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aus+uk / uk.d-i-y / Re: AC LED Bulbs for Push Bike

SubjectAuthor
* AC LED Bulbs for Push Bikethescullster
+- Re: AC LED Bulbs for Push BikeThe Natural Philosopher
+* Re: AC LED Bulbs for Push BikeSpike
|`- Re: AC LED Bulbs for Push BikeTheo
+* Re: AC LED Bulbs for Push BikeMartin Brown
|+- Re: AC LED Bulbs for Push BikeClive Arthur
|`* Re: AC LED Bulbs for Push BikeBrian
| `- Re: AC LED Bulbs for Push BikeMartin Brown
+- Re: AC LED Bulbs for Push BikeTheo
+* Re: AC LED Bulbs for Push BikeJeff Layman
|`- Re: AC LED Bulbs for Push BikeTheo
+* Re: AC LED Bulbs for Push Bikethescullster
|`* Re: AC LED Bulbs for Push BikePaul
| +- Re: AC LED Bulbs for Push BikePaul
| `* Re: AC LED Bulbs for Push BikeMartin Brown
|  `- Re: AC LED Bulbs for Push BikePaul
`* Re: AC LED Bulbs for Push BikeScott
 +* Re: AC LED Bulbs for Push BikePaul
 |`- Re: AC LED Bulbs for Push BikeAnimal
 `* Re: AC LED Bulbs for Push BikeSteve Walker
  `- Re: AC LED Bulbs for Push BikeScott

1
AC LED Bulbs for Push Bike

<t50297$127$1@dont-email.me>

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From: Phi...@nospam.com (thescullster)
Newsgroups: uk.d-i-y
Subject: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 09:35:50 +0100
Organization: A noiseless patient Spider
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 by: thescullster - Thu, 5 May 2022 08:35 UTC

Hi All

I have recently resurrected my push bike for roaming the local villages.

This has a Sturmey Archer dynohub which generates around 12v AC.

Currently this drives a front and back light, both 6v.
The bulbs are the kind that have the filaments folded back on the
flattened bulb body (rather than the pin type) IYSWIM. They simply push
into the bulb holder, not the bayonet type.

Is there an LED equivalent of these that is worth considering?
I know I really need auxiliary lighting for after dark stationary periods.

Thanks

Phil

Re: AC LED Bulbs for Push Bike

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From: tnp...@invalid.invalid (The Natural Philosopher)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 09:59:26 +0100
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 by: The Natural Philosop - Thu, 5 May 2022 08:59 UTC

On 05/05/2022 09:35, thescullster wrote:
> Hi All
>
> I have recently resurrected my push bike for roaming the local villages.
>
> This has a Sturmey Archer dynohub which generates around 12v AC.
>
> Currently this drives a front and back light, both 6v.
> The bulbs are the kind that have the filaments folded back on the
> flattened bulb body (rather than the pin type) IYSWIM. They simply push
> into the bulb holder, not the bayonet type.
>
> Is there an LED equivalent of these that is worth considering?
> I know I really need auxiliary lighting for after dark stationary periods.
>
> Thanks
>
> Phil
Id be inclined to switch to rechargeable batteries and LED lights and
see if you could make a charge circuit out of the dynohub.

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

Re: AC LED Bulbs for Push Bike

<jdhircF88ucU1@mid.individual.net>

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From: Aero.Sp...@mail.invalid (Spike)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 09:14:21 +0000
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 by: Spike - Thu, 5 May 2022 09:14 UTC

On 05/05/2022 08:35, thescullster wrote:
> Hi All

> I have recently resurrected my push bike for roaming the local villages.

> This has a Sturmey Archer dynohub which generates around 12v AC.

> Currently this drives a front and back light, both 6v.
> The bulbs are the kind that have the filaments folded back on the
> flattened bulb body (rather than the pin type) IYSWIM. They simply push
> into the bulb holder, not the bayonet type.

> Is there an LED equivalent of these that is worth considering?
> I know I really need auxiliary lighting for after dark stationary periods.

Go for 'proper' modern battery-powered LED lights, the cycling world has
all sorts of cycle lights available, from ones that help you see where
you're going to 'make a statement' type of flashing monsters designed to
dazzle drivers.

Here's one review:

<https://www.bikeradar.com/advice/buyers-guides/best-bike-lights-for-road-cycling/>

--
Spike

Re: AC LED Bulbs for Push Bike

<t504lo$c4t$1@gioia.aioe.org>

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From: '''newsp...@nonad.co.uk (Martin Brown)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 10:16:39 +0100
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 by: Martin Brown - Thu, 5 May 2022 09:16 UTC

On 05/05/2022 09:35, thescullster wrote:
> Hi All
>
> I have recently resurrected my push bike for roaming the local villages.
>
> This has a Sturmey Archer dynohub which generates around 12v AC.
>
> Currently this drives a front and back light, both 6v.
> The bulbs are the kind that have the filaments folded back on the
> flattened bulb body (rather than the pin type) IYSWIM. They simply push
> into the bulb holder, not the bayonet type.
>
> Is there an LED equivalent of these that is worth considering?
> I know I really need auxiliary lighting for after dark stationary periods.

Rectify the AC with a bridge rectifier and you will have ~15v DC.

That would drive a chain of 3 power LEDs in series with a 100R 1W
dropper resistor at about 300mA (or 1 power LED and a 390R 5W resistor).

You could also charge a nominal 12v NiMH battery pack off the DC supply
so that when you are stationary the lights stay on.

Making a DIY LED bulb that would fit into the existing fixures might be
interesting an LED with a reverse diode across it and a current limiting
resistor in series would work if you can assemble it in the space.

--
Regards,
Martin Brown

Re: AC LED Bulbs for Push Bike

<aKk*sJoNy@news.chiark.greenend.org.uk>

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From: theom+n...@chiark.greenend.org.uk (Theo)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: 05 May 2022 11:13:28 +0100 (BST)
Organization: University of Cambridge, England
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 by: Theo - Thu, 5 May 2022 10:13 UTC

thescullster <Phil@nospam.com> wrote:
> Is there an LED equivalent of these that is worth considering?
> I know I really need auxiliary lighting for after dark stationary periods.

Look for replacement lights with a 'standlight', which is a capacitor that
keeps the LEDs running for a few minutes while stationary. 6v AC lights
designed to be driven from a dynamo are common, they have the rectification
and voltage clamping built in.

Busch and Mueller are good:
https://www.bumm.de/en/products/dynamo-rucklichter.html?filter%5Bstandlicht%5D=1

(in Germany dynamos are more common, in other countries they prefer battery
lights. At least pre-Brexit it was often cheaper to buy them from Germany
or the Netherlands)

You can try and just replace the bulbs in your existing lights with LEDs,
but you'll find the beam angles all wrong, since the diffuser is designed
for a filament rather than an LED source. Better to go for a light that has
all that properly designed.

Theo

Re: AC LED Bulbs for Push Bike

<cKk*xWoNy@news.chiark.greenend.org.uk>

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From: theom+n...@chiark.greenend.org.uk (Theo)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: 05 May 2022 12:09:18 +0100 (BST)
Organization: University of Cambridge, England
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 by: Theo - Thu, 5 May 2022 11:09 UTC

Spike <Aero.Spike@mail.invalid> wrote:
> Go for 'proper' modern battery-powered LED lights, the cycling world has
> all sorts of cycle lights available, from ones that help you see where
> you're going to 'make a statement' type of flashing monsters designed to
> dazzle drivers.

At the cheaper end, ebay has plenty of Chinese lights which have an 18650 or
similar lithium cell inside and charge off USB. You do need to charge them,
unlike a dynamo, but you don't need to charge them that often. Frequently
they quote one hour of runtime in peak mode, but you can often get away
without using peak brightness and that improves the battery life.

The downside though of those kind of pencil-torch lights is they're often
very 'spotlighty', which means you don't get a great beam spread. OK for
seeing the pothole immediately in front of you, but not for seeing the road
20m+ in front so you have time to avoid the pothole. The difference with a
quality light is the beam spread is better, and if it's solidly mounted to
the bike you can align it properly, rather than lighting your front wheel or
dazzling/shooting over the top of cars. Many of the cheap ones have flimsy
rubber mounts that aren't good for alignment.

Theo

Re: AC LED Bulbs for Push Bike

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From: jmlay...@invalid.invalid (Jeff Layman)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 12:31:32 +0100
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 by: Jeff Layman - Thu, 5 May 2022 11:31 UTC

On 05/05/2022 09:35, thescullster wrote:
> Hi All
>
> I have recently resurrected my push bike for roaming the local villages.
>
> This has a Sturmey Archer dynohub which generates around 12v AC.
>
> Currently this drives a front and back light, both 6v.
> The bulbs are the kind that have the filaments folded back on the
> flattened bulb body (rather than the pin type) IYSWIM. They simply push
> into the bulb holder, not the bayonet type.
>
> Is there an LED equivalent of these that is worth considering?
> I know I really need auxiliary lighting for after dark stationary periods.

<https://forum.cyclinguk.org/viewtopic.php?t=46433&start=15>
<https://www.bikeforums.net/electronics-lighting-gadgets/967199-retrofitting-vintage-lights-leds-sturmey-archer-dynohub-compatibility.html>
<http://www.bicyclehub.co.uk/sturmey-archer-gh6-dynohub>

etc.

--

Jeff

Re: AC LED Bulbs for Push Bike

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From: cli...@nowaytoday.co.uk (Clive Arthur)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 12:39:38 +0100
Organization: A noiseless patient Spider
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 by: Clive Arthur - Thu, 5 May 2022 11:39 UTC

On 05/05/2022 10:16, Martin Brown wrote:
<snipped>

> Rectify the AC with a bridge rectifier and you will have ~15v DC.
>
> That would drive a chain of 3 power LEDs in series with a 100R 1W
> dropper resistor at about 300mA (or 1 power LED and a 390R 5W resistor).
>
> You could also charge a nominal 12v NiMH battery pack off the DC supply
> so that when you are stationary the lights stay on.
>
> Making a DIY LED bulb that would fit into the existing fixures might be
> interesting an LED with a reverse diode across it and a current limiting
> resistor in series would work if you can assemble it in the space.
>
The dynamo's most likely more of a constant current than constant
voltage. Rectify with a bridge made from LEDs, and use a supercap
across the bridge output with further LEDs as a standlight.

[Wireless World idea from way back.]

--
Cheers
Clive

Re: AC LED Bulbs for Push Bike

<aKk*c7oNy@news.chiark.greenend.org.uk>

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From: theom+n...@chiark.greenend.org.uk (Theo)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: 05 May 2022 12:54:48 +0100 (BST)
Organization: University of Cambridge, England
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 by: Theo - Thu, 5 May 2022 11:54 UTC

Jeff Layman <jmlayman@invalid.invalid> wrote:
> On 05/05/2022 09:35, thescullster wrote:
> > Hi All
> >
> > I have recently resurrected my push bike for roaming the local villages.
> >
> > This has a Sturmey Archer dynohub which generates around 12v AC.
>
> <http://www.bicyclehub.co.uk/sturmey-archer-gh6-dynohub>

That has an interesting comment that the WWII-era Dynohubs were initially
12v, and later settled on 6v. If the OP's setup is a 12V antique it may be
driving two 6v bulbs in series, rather than the usual arrangement where it's
6v out of the dynamo to two parallel 6v bulbs.

However bike dynamos are roughly AC constant current devices - under no-load
conditions you can get the open-circuit voltage to go quite high, but once a
load is applied it will drop down substantially. If the OP is measuring the
no-load output of a 6v dynamo I'm not surprised it goes to 12v or more. You
still want 6v lights for that.

The main issue was when your 2.4W front bulb blew or became disconnected and
suddenly your 3W dynamo output was going through the 0.6W rear bulb, which
would cause the voltage to rise and that one to blow too. Modern LED dynamo
lights have zener diode clamps to absorb spikes like this so it's not a
problem.

Theo

Re: AC LED Bulbs for Push Bike

<t50roh$5f6$2@dont-email.me>

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From: noi...@lid.org (Brian)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 15:50:41 -0000 (UTC)
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 by: Brian - Thu, 5 May 2022 15:50 UTC

Martin Brown <'''newspam'''@nonad.co.uk> wrote:
> On 05/05/2022 09:35, thescullster wrote:
>> Hi All
>>
>> I have recently resurrected my push bike for roaming the local villages.
>>
>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>
>> Currently this drives a front and back light, both 6v.
>> The bulbs are the kind that have the filaments folded back on the
>> flattened bulb body (rather than the pin type) IYSWIM. They simply push
>> into the bulb holder, not the bayonet type.
>>
>> Is there an LED equivalent of these that is worth considering?
>> I know I really need auxiliary lighting for after dark stationary periods.
>
> Rectify the AC with a bridge rectifier and you will have ~15v DC.
>
> That would drive a chain of 3 power LEDs in series with a 100R 1W
> dropper resistor at about 300mA (or 1 power LED and a 390R 5W resistor).
>
> You could also charge a nominal 12v NiMH battery pack off the DC supply
> so that when you are stationary the lights stay on.
>
> Making a DIY LED bulb that would fit into the existing fixures might be
> interesting an LED with a reverse diode across it and a current limiting
> resistor in series would work if you can assemble it in the space.
>

That is the way to go.

Long before LEDs, when I was a teenager, I did something similar with
ordinary bulbs and some rechargeable batteries, with one of the dynamos the
ran on the side of the rear tyre.

Re: AC LED Bulbs for Push Bike

<t50tal$ar8$1@gioia.aioe.org>

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From: '''newsp...@nonad.co.uk (Martin Brown)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Thu, 5 May 2022 17:17:24 +0100
Organization: Aioe.org NNTP Server
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 by: Martin Brown - Thu, 5 May 2022 16:17 UTC

On 05/05/2022 16:50, Brian wrote:
> Martin Brown <'''newspam'''@nonad.co.uk> wrote:
>> On 05/05/2022 09:35, thescullster wrote:
>>> Hi All
>>>
>>> I have recently resurrected my push bike for roaming the local villages.
>>>
>>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>>
>>> Currently this drives a front and back light, both 6v.
>>> The bulbs are the kind that have the filaments folded back on the
>>> flattened bulb body (rather than the pin type) IYSWIM. They simply push
>>> into the bulb holder, not the bayonet type.
>>>
>>> Is there an LED equivalent of these that is worth considering?
>>> I know I really need auxiliary lighting for after dark stationary periods.
>>
>> Rectify the AC with a bridge rectifier and you will have ~15v DC.
>>
>> That would drive a chain of 3 power LEDs in series with a 100R 1W
>> dropper resistor at about 300mA (or 1 power LED and a 390R 5W resistor).
>>
>> You could also charge a nominal 12v NiMH battery pack off the DC supply
>> so that when you are stationary the lights stay on.
>>
>> Making a DIY LED bulb that would fit into the existing fixures might be
>> interesting an LED with a reverse diode across it and a current limiting
>> resistor in series would work if you can assemble it in the space.
>>
>
> That is the way to go.
>
> Long before LEDs, when I was a teenager, I did something similar with
> ordinary bulbs and some rechargeable batteries, with one of the dynamos the
> ran on the side of the rear tyre.

In a DIY sense maybe.

But modern LED based bike lights are now so efficient that battery
powered ones (rechargeable or not) are quite long lasting.

4Ah D cells @300mA ~ 12 hours continuous use. 2Ah AA cells ~ 6 hours.

The OP might be better off buying something intended for the purpose.
NB Rear red LED lights have different voltage drop ~2.2v each (and it
makes good sense to make red light efficiently rather than the old style
white filament lamp with a clear red filter).

--
Regards,
Martin Brown

Re: AC LED Bulbs for Push Bike

<t52j9p$cj2$1@dont-email.me>

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From: Phi...@nospam.com (thescullster)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Fri, 6 May 2022 08:38:32 +0100
Organization: A noiseless patient Spider
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 by: thescullster - Fri, 6 May 2022 07:38 UTC

On 05/05/2022 09:35, thescullster wrote:
> Hi All
>
> I have recently resurrected my push bike for roaming the local villages.
>
> This has a Sturmey Archer dynohub which generates around 12v AC.
>
> Currently this drives a front and back light, both 6v.
> The bulbs are the kind that have the filaments folded back on the
> flattened bulb body (rather than the pin type) IYSWIM. They simply push
> into the bulb holder, not the bayonet type.
>
> Is there an LED equivalent of these that is worth considering?
> I know I really need auxiliary lighting for after dark stationary periods.
>
> Thanks
>
> Phil

Guys

Thanks for all your informed comments.

To answer the question raised by Theo, the bike is described as Vintage
in posts I have read. It's a BSA Bermuda dating from around 1970.

I was measuring the 12v with no load on the dynamo and assumed that the
two bulbs were in series. The lights had stopped working, but this was
due to a detached connection and once reconnected both bulbs were found
to be fine.

Of the suggestions offered, I think I prefer the option to use the
dynamo to charge a battery pack to feed more modern lights.

Phil

Re: AC LED Bulbs for Push Bike

<t546t8$uo0$1@gioia.aioe.org>

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From: nos...@needed.invalid (Paul)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Fri, 6 May 2022 18:19:21 -0400
Organization: Aioe.org NNTP Server
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 by: Paul - Fri, 6 May 2022 22:19 UTC

On 5/6/2022 3:38 AM, thescullster wrote:
> On 05/05/2022 09:35, thescullster wrote:
>> Hi All
>>
>> I have recently resurrected my push bike for roaming the local villages.
>>
>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>
>> Currently this drives a front and back light, both 6v.
>> The bulbs are the kind that have the filaments folded back on the flattened bulb body (rather than the pin type) IYSWIM. They simply push into the bulb holder, not the bayonet type.
>>
>> Is there an LED equivalent of these that is worth considering?
>> I know I really need auxiliary lighting for after dark stationary periods.
>>
>> Thanks
>>
>> Phil
>
> Guys
>
> Thanks for all your informed comments.
>
> To answer the question raised by Theo, the bike is described as Vintage in posts I have read.  It's a BSA Bermuda dating from around 1970.
>
> I was measuring the 12v with no load on the dynamo and assumed that the two bulbs were in series.  The lights had stopped working, but this was due to a detached connection and once reconnected both bulbs were found to be fine.
>
> Of the suggestions offered, I think I prefer the option to use the dynamo to charge a battery pack to feed more modern lights.
>
> Phil

I've done this.

You do AC to DC conversion, just in the same way you would do it
for a hobby 5V supply in the old days. In the old days of digital
logic breadboarding, you would use

transformer - bridge rectifier - filter cap - 7805_regulator

That's an example of an inefficient linear implementation of a 5V supply.

You will be replacing that with:

hub/bottle_gen - bridge rectifier - filter cap ==> wide range DC out

That's the very most basic part of it (the three items produce
"wide ranging DC" and more circuit is needed than that).
The three named components are only "sufficient" under
a very special set of circumstances.

My power source on the current commuter bicycle is a 1950's...

Sturmey Archer bottle generator 6VAC 0.5A [Danger: Max Output 100VAC at 0 amps]

All that you need, to start, is a bridge rectifier.
I built mine from four individual 2 ampere Schottky
rectifiers arranged in the bridge. Schottky improve
the efficiency of the rectifier stage slightly. Considering
the gobs of power yours has, any old bridge rectifier will do.
The limiter is intended to clip output peaks, so the
generator never rises to the 100VAC level by accident.
You insert zeners in series so "the zeners don't get hot
in normal operation", yet the filter cap is protected
against the possibility of excess voltage. Your 12V hub
might require four zeners in series like that (band "up").
Your filter cap will need a higher volts rating. Because
your hub has twice the voltage of my bottle gen. The
bridge rectifier, four leg device, have those very
symbols printed right on the plastic. Hookup is simple.

+---------+
Generator ~ ------| ~ + |--------+------------------+---------------+
| | _|_/ | |
Gen Ground ~ ------| ~ - |--+ / ^ 5.1V 5W --- |
+---------+ | _|_/ zener etc V 2.5V 20mA | +
| / ^ --- White LED --- 47uF 16V
| | "Limiter" | --- filter cap
| | --- | -
| | V 2.5V 20mA |
| | --- White LED | Filter cap to
| | | | be placed next
+-----+------------------+---------------+ to LED tree!

\__________________/

This section is your
"basic unit of light"

The audience members will immediately point out "you idiot, you forgot
the *resistor* to protect the LED".

Well, as it turns out, the generators of the day, were constant current
sources. On my generator, it approximately wants to produce 0.5 amperes,
no matter what. You must be doing around 5 MPH for the output to rise
sufficiently for lighting usage.

The voltage drops in my circuit are approximately

0.5V (first bridge rectifier diode)
2.5V LED
2.5V LED
0.5V (second bridge rectifier diode)
------
6.0V but this is relatively unimportant (efficiency issue maybe)
------

Now the next thing I'm going to do, is put "multiple basic units of light"
in parallel. The audience will howl "this will result in current hogging!".
Yes, it might... if the LEDs had not been carefully matched on Vf at
a fixed If. I set up a test jig, and measured all the LEDs for their
Vf. Then, pairs of LEDs, their "total Vf" is the same as all other
"basic units of light". I used a spread sheet, to track all my LEDs.

Using 48 pairs of LEDs, uses up the 0.5 ampere being offered.
Each LED pair has about 10mA flowing. If the cable for the front
light falls off, the 24 pairs sink 20mA each. In other words, by
over-rating the lights a bit, if half the load falls away,
the second array gets "twice as bright" but nothing burns.

The more LEDs placed in series, the easier it is to tune the Vf of
each vertical column of LEDs. If the LED trees were one LED high,
this would be impossible to arrange (a single VF isn't close enough).
Two LEDs (what I used) is the shortest column that is practical.

The result is, my lighting system has *no resistors at all*. The
internal impedance of the Sturmey Archer is the only impedance
in the circuit.

The circuit still has *lots* of failure modes. For example, if one
LED fails short, the second LED in the stack carries *all* the
generator current, damaging the second LED. If your array goes
dark and one LED is "blasting out light", you know its mate
failed short.

The two stacked Zeners, are to try to avoid blowing the filter
caps. If the circuit loses its load for any reason (circuit "rusts out"),
the filter caps *might* be the most expensive part of the circuit.
You stack enough 5.1V zeners, so that the zeners do not
normally conduct. If the filter cap is 35V for example,
you might stack four zeners and clamp the max positive rail
at 20.4V.

I used ceramic capacitors for a distributed filter. At the time,
they were "priced to clear" at Newark (Element14/AVNET). I really
should have bought two or three times as many, as the price
rose 5X the year after. They are no longer practical at this point.
As you would expect, not in stock either. If you lived in Japan,
these would be easy to get. But not here.

https://canada.newark.com/w/search/prl/results?st=EMK325BJ476MM-T&scope=partnumberlookahead&searchref=searchlookahead

By placing the ceramic capacitor right next to the LED column, the
impedance of the distribution cables is taken out of the circuit.
If you "clump" all the capacitors at one end of the bicycle,
an inferior level of ripple will be seen in the light output.

The purpose of using ceramic SMT caps in a project like this,
is there are no legs to break off. A natural choice would be
the usage of an electrolytic. They have legs. It takes only
*one week* of bicycle vibrations (pot holes) to break a leg
off an electrolytic capacitor. You might use potting compound
to fasten the body of the electrolytic to the PCB, but
I'm not interested in testing the reliability of those
capacitor legs any more.

The LED diodes are an inherently low-impedance load. The front and
back light on the bicycle are joined with 14ga lamp cord. The
bicycle frame is not relied upon for any purpose. The electronics
are insulated from the frame. One leg of the generator
output, is tied to bicycle frame (normally), so we have to assume
the bicycle frame has AC on it. Do not touch any of the DC
part of the circuit, to frame.

I pick up both "~" outputs of the generator, as close to the
generator as I can get, then use my decent wire to run to
any other conversion boxes on the bike.

Your hub is a 12V circuit, likely 1 ampere output, The circuit
will need to be fiddled a bit, to make best usage of the power.
You could use four LEDs in a stack, which is 10V approximately.
The LEDs are 2.5V, because the current flow is so low in each column.

0.6V (first bridge rectifier diode) [More total current, more Vf in schottky]
2.5V LED
2.5V LED
2.5V LED
2.5V LED
0.6V (second bridge rectifier diode)
------
11.2V but this is relatively unimportant (you want it sorta close to 12V or so)
------

We could put five LEDs in a stack, and the generator output
current will drop a bit.


Click here to read the complete article
Re: AC LED Bulbs for Push Bike

<t5498a$1o0l$1@gioia.aioe.org>

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From: nos...@needed.invalid (Paul)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Fri, 6 May 2022 18:59:22 -0400
Organization: Aioe.org NNTP Server
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 by: Paul - Fri, 6 May 2022 22:59 UTC

On 5/6/2022 6:19 PM, Paul wrote:
> On 5/6/2022 3:38 AM, thescullster wrote:
>> On 05/05/2022 09:35, thescullster wrote:
>>> Hi All
>>>
>>> I have recently resurrected my push bike for roaming the local villages.
>>>
>>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>>
>>> Currently this drives a front and back light, both 6v.
>>> The bulbs are the kind that have the filaments folded back on the flattened bulb body (rather than the pin type) IYSWIM. They simply push into the bulb holder, not the bayonet type.
>>>
>>> Is there an LED equivalent of these that is worth considering?
>>> I know I really need auxiliary lighting for after dark stationary periods.
>>>
>>> Thanks
>>>
>>> Phil
>>
>> Guys
>>
>> Thanks for all your informed comments.
>>
>> To answer the question raised by Theo, the bike is described as Vintage in posts I have read.  It's a BSA Bermuda dating from around 1970.
>>
>> I was measuring the 12v with no load on the dynamo and assumed that the two bulbs were in series.  The lights had stopped working, but this was due to a detached connection and once reconnected both bulbs were found to be fine.
>>
>> Of the suggestions offered, I think I prefer the option to use the dynamo to charge a battery pack to feed more modern lights.
>>
>> Phil
>
> I've done this.

Here is a picture of the back unit, under the seat,
which does AC to DC conversion and has a LED bank.

[Picture]

https://i.postimg.cc/JhRjRv5b/bicycle-light.gif

Paul

Re: AC LED Bulbs for Push Bike

<pa2c7h1koectt8csoc0e2pdfscdlsa1lpo@4ax.com>

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From: newsgro...@gefion.myzen.co.uk (Scott)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Sat, 07 May 2022 06:54:05 +0100
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 by: Scott - Sat, 7 May 2022 05:54 UTC

On Thu, 5 May 2022 09:35:50 +0100, thescullster <Phil@nospam.com>
wrote:

>Hi All
>
>I have recently resurrected my push bike for roaming the local villages.
>
>This has a Sturmey Archer dynohub which generates around 12v AC.
>
>Currently this drives a front and back light, both 6v.
>The bulbs are the kind that have the filaments folded back on the
>flattened bulb body (rather than the pin type) IYSWIM. They simply push
>into the bulb holder, not the bayonet type.
>
>Is there an LED equivalent of these that is worth considering?
>I know I really need auxiliary lighting for after dark stationary periods.
>
I always understood dynamos were DC and alternators AC. Am I
mistaken?

Re: AC LED Bulbs for Push Bike

<t55aee$1klg$1@gioia.aioe.org>

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From: '''newsp...@nonad.co.uk (Martin Brown)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Sat, 7 May 2022 09:25:50 +0100
Organization: Aioe.org NNTP Server
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 by: Martin Brown - Sat, 7 May 2022 08:25 UTC

On 06/05/2022 23:19, Paul wrote:
> On 5/6/2022 3:38 AM, thescullster wrote:
>> On 05/05/2022 09:35, thescullster wrote:
>>> Hi All
>>>
>>> I have recently resurrected my push bike for roaming the local villages.
>>>
>>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>>
>>> Currently this drives a front and back light, both 6v.
>>> The bulbs are the kind that have the filaments folded back on the
>>> flattened bulb body (rather than the pin type) IYSWIM. They simply
>>> push into the bulb holder, not the bayonet type.
>>>
>>> Is there an LED equivalent of these that is worth considering?
>>> I know I really need auxiliary lighting for after dark stationary
>>> periods.
>>>
>>> Thanks
>>>
>>> Phil
>>
>> Guys
>>
>> Thanks for all your informed comments.
>>
>> To answer the question raised by Theo, the bike is described as
>> Vintage in posts I have read.  It's a BSA Bermuda dating from around
>> 1970.
>>
>> I was measuring the 12v with no load on the dynamo and assumed that
>> the two bulbs were in series.  The lights had stopped working, but
>> this was due to a detached connection and once reconnected both bulbs
>> were found to be fine.
>>
>> Of the suggestions offered, I think I prefer the option to use the
>> dynamo to charge a battery pack to feed more modern lights.
>>
>> Phil
>
> I've done this.
>
> You do AC to DC conversion, just in the same way you would do it
> for a hobby 5V supply in the old days. In the old days of digital
> logic breadboarding, you would use
>
>     transformer - bridge rectifier - filter cap - 7805_regulator
>
> That's an example of an inefficient linear implementation of a 5V supply.
>
> You will be replacing that with:
>
>     hub/bottle_gen  -  bridge rectifier - filter cap   ==> wide range
> DC out
>
> That's the very most basic part of it (the three items produce
> "wide ranging DC" and more circuit is needed than that).
> The three named components are only "sufficient" under
> a very special set of circumstances.
>
> My power source on the current commuter bicycle is a 1950's...
>
>    Sturmey Archer bottle generator 6VAC 0.5A  [Danger: Max Output
> 100VAC at 0 amps]
>
> All that you need, to start, is a bridge rectifier.
> I built mine from four individual 2 ampere Schottky
> rectifiers arranged in the bridge. Schottky improve
> the efficiency of the rectifier stage slightly. Considering
> the gobs of power yours has, any old bridge rectifier will do.
> The limiter is intended to clip output peaks, so the
> generator never rises to the 100VAC level by accident.
> You insert zeners in series so "the zeners don't get hot
> in normal operation", yet the filter cap is protected
> against the possibility of excess voltage. Your 12V hub
> might require four zeners in series like that (band "up").
> Your filter cap will need a higher volts rating. Because
> your hub has twice the voltage of my bottle gen.  The
> bridge rectifier, four leg device, have those very
> symbols printed right on the plastic. Hookup is simple.
>
>                        +---------+
>    Generator   ~ ------| ~     + |
--------+------------------+---------------+
>                        |         |       _|_/
> |               |
>    Gen Ground  ~ ------| ~     - |--+   / ^   5.1V 5W
> ---              |
>                        +---------+  |    _|_/ zener etc      V  2.5V
> 20mA   | +
>                                     |   / ^                 --- White
> LED   ---  47uF 16V
>                                     |     |  "Limiter"
> |              ---  filter cap
>                                     |     |
> ---              | -
>                                     |     |                  V  2.5V
> 20mA   |
>                                     |     |                 --- White
> LED    | Filter cap to
>                                     |     |
> |               | be placed next
>
> +-----+------------------+---------------+ to LED tree!
>
>
> \__________________/
>
>                                                            This section
> is your
>                                                            "basic unit
> of light"
>
> The audience members will immediately point out "you idiot, you forgot
> the *resistor* to protect the LED".
>
> Well, as it turns out, the generators of the day, were constant current
> sources. On my generator, it approximately wants to produce 0.5 amperes,
> no matter what. You must be doing around 5 MPH for the output to rise
> sufficiently for lighting usage.
>
> The voltage drops in my circuit are approximately
>
>     0.5V (first bridge rectifier diode)
>     2.5V LED
>     2.5V LED
>     0.5V (second bridge rectifier diode)
>    ------
>     6.0V    but this is relatively unimportant (efficiency issue maybe)
>    ------
>
> Now the next thing I'm going to do, is put "multiple basic units of light"
> in parallel. The audience will howl "this will result in current hogging!".
> Yes, it might... if the LEDs had not been carefully matched on Vf at
> a fixed If. I set up a test jig, and measured all the LEDs for their
> Vf. Then, pairs of LEDs, their "total Vf" is the same as all other
> "basic units of light". I used a spread sheet, to track all my LEDs.
>
> Using 48 pairs of LEDs, uses up the 0.5 ampere being offered.
> Each LED pair has about 10mA flowing. If the cable for the front
> light falls off, the 24 pairs sink 20mA each. In other words, by
> over-rating the lights a bit, if half the load falls away,
> the second array gets "twice as bright" but nothing burns.
>
> The more LEDs placed in series, the easier it is to tune the Vf of
> each vertical column of LEDs. If the LED trees were one LED high,
> this would be impossible to arrange (a single VF isn't close enough).
> Two LEDs (what I used) is the shortest column that is practical.
>
> The result is, my lighting system has *no resistors at all*. The
> internal impedance of the Sturmey Archer is the only impedance
> in the circuit.
>
> The circuit still has *lots* of failure modes. For example, if one
> LED fails short, the second LED in the stack carries *all* the
> generator current, damaging the second LED. If your array goes
> dark and one LED is "blasting out light", you know its mate
> failed short.
>
> The two stacked Zeners, are to try to avoid blowing the filter
> caps. If the circuit loses its load for any reason (circuit "rusts out"),
> the filter caps *might* be the most expensive part of the circuit.
> You stack enough 5.1V zeners, so that the zeners do not
> normally conduct. If the filter cap is 35V for example,
> you might stack four zeners and clamp the max positive rail
> at 20.4V.

A couple of quick points.

If you are going to only draw 20mA from the supply you might as well
limit the current with a high wattage resistor and use much cheaper less
beefy standard Zener diodes.

Rough values

R = 470 ohm 1/3W (20mA approx)
R = 220 ohm 1W (50mA approx)

Zeners can then be standard 300mW types in both cases.

High power Zeners are expensive and increasingly rare these days.

A bit more care needed with the computations and heatsinking if you want
to drive higher power LEDs at 300mA or 0.5A.

BTW 6mm White LEDs will run fine at 50mA and about 4.2v voltage drop.
(a 4v voltage drop is more typical for a white LED - not 2.5v)

--
Regards,
Martin Brown

Re: AC LED Bulbs for Push Bike

<t55jq8$1f4v$1@gioia.aioe.org>

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From: nos...@needed.invalid (Paul)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Sat, 7 May 2022 07:05:45 -0400
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 by: Paul - Sat, 7 May 2022 11:05 UTC

On 5/7/2022 1:54 AM, Scott wrote:
> On Thu, 5 May 2022 09:35:50 +0100, thescullster <Phil@nospam.com>
> wrote:
>
>> Hi All
>>
>> I have recently resurrected my push bike for roaming the local villages.
>>
>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>
>> Currently this drives a front and back light, both 6v.
>> The bulbs are the kind that have the filaments folded back on the
>> flattened bulb body (rather than the pin type) IYSWIM. They simply push
>> into the bulb holder, not the bayonet type.
>>
>> Is there an LED equivalent of these that is worth considering?
>> I know I really need auxiliary lighting for after dark stationary periods.
>>
> I always understood dynamos were DC and alternators AC. Am I
> mistaken?
>

You can check these things with a meter. You don't
have to leave it to chance.

You can also connect ceramic power resistors, and measure the V and I
with that fixed load, to give you some idea of what it can make. This
pre-supposes you have some idea what the output is, and want to make
a little chart for yourself, for prediction purposes.

These are the style of power resistor I might use for a home project.
They come in various ohm values and are handy for a quick test. (In
school labs, we might have "load boxes" with rotary switches for fun things
like this.)

https://www.amazon.com/NTE-ELECTRONICS-10W010-RESISTOR-WIREWOUND/dp/B00HPLNSUG

Because the generating device is constant current, once the speed is between
5 MPH and 30 MPH, the output should be pretty stable. V=RI. Inverting the
bicycle, would allow you to make a scheme to provide excitation (it's harder
to make a front wheel turn at a constant speed for this testing).

The old incandescent bulbs, didn't care. DC or
AC made them work. As long as the voltage level
was correct for the job.

LEDs are DC only. The small LEDs have a 5 volt max Peak Inverse Volts rating
(PIV). Large power LEDs *do not* allow reversal. The large power LEDs
sometimes even contain a reverse protection device inside, intended for
transient/ESD protection. Even working with the little LEDs, it's quite possible
you might inadvertently reverse the polarity and damage something (if the
voltages involved are way more than the 5V accident rating). The
LEDs in your computer (which are the small ones), the nice thing
about the 5V PIV, is you can reverse the cabling when assembling
a computer, and there will be no damage to the T1 3/4 LEDs on the case.

*******

You can see if you head over to Wiki, even they're a bit confused.
Showing some waveforms in the article, might have helped pass on
info about pulsating AC and pulsating DC waveforms. In the old
days, a pulsating DC could be "cleaned up" with a battery
as a cheesy form of regulation.

https://en.wikipedia.org/wiki/Alternator # "alternating current"

https://en.wikipedia.org/wiki/Electric_generator#Bicycles # bottle dynamos, hub dynamos

"The name is conventional as these are
small permanent-magnet alternators, not <=== AC
self-excited DC machines as are dynamos"

https://en.wikipedia.org/wiki/Dynamo

"direct current generators which use exclusively the self-excitation
(self-induction) principle to generate DC power."

"commutated direct current electric generator"

[See the section entitled "Commutation" as for how DC is possible]
It is pulsating DC, and needs to be filtered.

https://en.wikipedia.org/wiki/Magneto

"A magneto is an electrical generator that uses permanent magnets
to produce periodic pulses of alternating current. Unlike a dynamo,
a magneto does not contain a commutator to produce direct current."

The commutator in your electric hand drill, complete with sparks,
shows you why commutators are a bad idea. Like slip rings, they
can wear out, or a groove can be worn in the surface, or a
piece of grit in a carbon brush can make a mess. Good commutators
are so thick, they can be turned down on a lathe. But that's
only on big electric machines. Not fractional horsepower style devices.

My bicycle bottle generator, has no commutator or slip rings,
which would have been the least reliable part.

*******

With the hub or bottle options on bicycles, when
selecting incandescent bulbs, you need a bulb that
draws "just the right current". If the incandescent
bulb draws too little juice, the bulb "burns out
when you go down a hill". If the incandescent bulb
draws too much juice, then the bulb will be too dim
for car drivers to see you.

When changing the old incandescent bulbs, you had to
go through your "drawer full of bicycle bulbs", until
you found the exact right one for the job. You sweep
the hardware store, the bicycle shop, for these things.
The "shape" of some of them, hinted they might be the
right type, but you still had to read the legend printed
on the base! No incandescent bulbs with a lens on the
front ("penlight"), was ever the right type.

I nearly got run over one night, because the incandescent
bulb I was using on front and back, wasn't bright enough.
(This means the resistance of the bulb was slightly too low.)

That's when I started the LED replacement project. It
was the shock of nearly getting run over, that
provided the incentive. My array lights are much
brighter than the old incandescents. By a country mile.

I used to have a sealed beam on the bicycle (this is close to it,
but not quite)

https://www.bulbamerica.com/products/ge-6w-4-7v-4547-par36-g53-incandescent-bulb

but... I burned that out going down a hill one night (one of the
steepest hills in that city). A policeman pulled me over
five minutes later, for "no light", and I'm thinking to
myself "he's never going to believe my story".
Now, that was a nice light, but buying a second would
require fitting something to tame it. Since the bulb had no
decent structural fittings on it, you *glue* the bulb to a
fat dowel and bolt the dowel to the bicycle. The screw
terminals are only for electrical connections, not mechanical.

Paul

Re: AC LED Bulbs for Push Bike

<t55kns$3es$1@dont-email.me>

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From: ste...@walker-family.me.uk (Steve Walker)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Sat, 7 May 2022 12:21:32 +0100
Organization: A noiseless patient Spider
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 by: Steve Walker - Sat, 7 May 2022 11:21 UTC

On 07/05/2022 06:54, Scott wrote:
> On Thu, 5 May 2022 09:35:50 +0100, thescullster <Phil@nospam.com>
> wrote:
>
>> Hi All
>>
>> I have recently resurrected my push bike for roaming the local villages.
>>
>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>
>> Currently this drives a front and back light, both 6v.
>> The bulbs are the kind that have the filaments folded back on the
>> flattened bulb body (rather than the pin type) IYSWIM. They simply push
>> into the bulb holder, not the bayonet type.
>>
>> Is there an LED equivalent of these that is worth considering?
>> I know I really need auxiliary lighting for after dark stationary periods.
>>
> I always understood dynamos were DC and alternators AC. Am I
> mistaken?

That's certainly the terms used when referring to cars, but bike ones
are normally known as dynamos and, in all likelihood are AC - why have
the additional complication of a commutator and brushes or a rectifier,
just to drive filament lamps that are equally happy with ac or dc?

Re: AC LED Bulbs for Push Bike

<oslc7hlggql5u0aildfgsv1vf3ljcbdig4@4ax.com>

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From: newsgro...@gefion.myzen.co.uk (Scott)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Sat, 07 May 2022 12:28:40 +0100
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 by: Scott - Sat, 7 May 2022 11:28 UTC

On Sat, 7 May 2022 12:21:32 +0100, Steve Walker
<steve@walker-family.me.uk> wrote:

>On 07/05/2022 06:54, Scott wrote:
>> On Thu, 5 May 2022 09:35:50 +0100, thescullster <Phil@nospam.com>
>> wrote:
>>
>>> Hi All
>>>
>>> I have recently resurrected my push bike for roaming the local villages.
>>>
>>> This has a Sturmey Archer dynohub which generates around 12v AC.
>>>
>>> Currently this drives a front and back light, both 6v.
>>> The bulbs are the kind that have the filaments folded back on the
>>> flattened bulb body (rather than the pin type) IYSWIM. They simply push
>>> into the bulb holder, not the bayonet type.
>>>
>>> Is there an LED equivalent of these that is worth considering?
>>> I know I really need auxiliary lighting for after dark stationary periods.
>>>
>> I always understood dynamos were DC and alternators AC. Am I
>> mistaken?
>
>That's certainly the terms used when referring to cars, but bike ones
>are normally known as dynamos and, in all likelihood are AC - why have
>the additional complication of a commutator and brushes or a rectifier,
>just to drive filament lamps that are equally happy with ac or dc?

The train ones were called dynamos (for the lighting). I assumed they
were DC.

Re: AC LED Bulbs for Push Bike

<t58jqh$cvg$1@gioia.aioe.org>

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From: nos...@needed.invalid (Paul)
Newsgroups: uk.d-i-y
Subject: Re: AC LED Bulbs for Push Bike
Date: Sun, 8 May 2022 10:24:18 -0400
Organization: Aioe.org NNTP Server
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 by: Paul - Sun, 8 May 2022 14:24 UTC

On 5/7/2022 4:25 AM, Martin Brown wrote:

> A couple of quick points.
>
> If you are going to only draw 20mA from the supply you might as well limit the current with a high wattage resistor and use much cheaper less beefy standard Zener diodes.
>
> Rough values
>
> R = 470 ohm 1/3W (20mA approx)
> R = 220 ohm 1W   (50mA approx)
>
> Zeners can then be standard 300mW types in both cases.
>
> High power Zeners are expensive and increasingly rare these days.
>
> A bit more care needed with the computations and heatsinking if you want to drive higher power LEDs at 300mA or 0.5A.
>
> BTW 6mm White LEDs will run fine at 50mA and about 4.2v voltage drop.
> (a 4v voltage drop is more typical for a white LED - not 2.5v)
>

In any case, this is an easily DIY type project.

But you would only DIY it, if you cannot find
any ready-made solutions. You don't exactly save
money by building these yourself.

The main benefit, is never having to worry about
batteries. I have nothing to charge. Having had
battery lights before on a bike, I did not want
any batteries on there. Stand light or no.

*******

Yes, the first attempt, with high power LEDs, used
extruded cylindrical finned heatsinks.

| | <=== Copper pipe cap
| |
| ===== | <=== Star emitter, thermal paste to copper cap
+-------+
|| || || | <=== Extruded heatsink with radial fins
|| || || |
|| || || |
|| || || |
|| || || |

That's overkill for the power involved at the moment,
and I can't feel any heat in the metals. I use that
for "kitchen mood lighting" and it runs all day long.
There are two of those, running off a wall wart and
a small circuit board. So the materials were not
wasted. I found a use for them. It's just, as a bike
light, it sucked. The output pattern was not useful
in any way. Missing from the diagram, is a poly-carbonate
silvered mirror, which sits around the LED and reflects
the light out the front. It was tailor made for use
with the Star scheme (or so they claim).

With the array of small LEDs in the successful version
of the project, no heatsink is necessary.
There is free air circulation around the LED legs.
(You leave the legs on the LEDs, and the LEDs mount
in a drilled plate about an inch from the circuit board.)
Since light leaks out on all sides of the project,
car drivers can see you more easily from the side.

The "Star emitter" is a high power LED having nothing
to do with Star packaging particularly, which is
soldered to an alumina circuit board (the Star). The
alumina is part of the thermal path. They mount all
sorts and brands of LEDs on those plates now. But
in small, hobbyist, quantity.

When you get someone else to mount the power LED for
you, you don't have to worry about damaging the LED
your own self. This is just an example of one
available this year. The older ones were white,
and there's different wiring patterns for the
quad LEDs (which is what I used, was a quad, and the
quad is uncommitted wiring with eight contacts). With
the quad, you can make a 3.2V LED, a 6.4V LED, a 12.8V LED.
The quad LED, all the dies have matched characteristics,
so you can do series-parallel combos if you want.

https://www.pcboard.ca/high-power-led-3-watt.html

https://www.ledsupply.com/blog/wp-content/uploads/2015/07/Untitled-Banner-64.png

Since you rely on middle men or small shops to do
a Star for you, you don't get an infinite choice on
materials. They mount whatever is "popular" at the moment.

The first example there, the LED is well suited to
hobbyist use. It's some of the SMT ones with contacts
on the bottom, it's better to get someone else to do those
for you.

On the second Star example, the LED electrical contacts
are on the bottom, plus a heat slug.

|||||||| <=== electrical (+)

|||||||| \
|||||||| \___ Supports heat transfer
|||||||| / into the thermally conductive substrate

|||||||| <=== electrical (-)

Working with power LEDs is a bit different than the ease
of working with T1 3/4 sized LEDs. Most of the work on
the LED array version, is... "boring". Lots and lots of holes
to drill with your hand drill. Ugh.

Paul

Re: AC LED Bulbs for Push Bike

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Subject: Re: AC LED Bulbs for Push Bike
From: tabbyp...@gmail.com (Animal)
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 by: Animal - Sun, 8 May 2022 20:38 UTC

On Saturday, 7 May 2022 at 12:05:51 UTC+1, Paul wrote:
> On 5/7/2022 1:54 AM, Scott wrote:

> LEDs are DC only. The small LEDs have a 5 volt max Peak Inverse Volts rating
> (PIV). Large power LEDs *do not* allow reversal. The large power LEDs
> sometimes even contain a reverse protection device inside, intended for
> transient/ESD protection. Even working with the little LEDs, it's quite possible
> you might inadvertently reverse the polarity and damage something (if the
> voltages involved are way more than the 5V accident rating). The
> LEDs in your computer (which are the small ones), the nice thing
> about the 5V PIV, is you can reverse the cabling when assembling
> a computer, and there will be no damage to the T1 3/4 LEDs on the case.

LED V_r rating is often misunderstood. They aren't tested for it, as it's usually irrelevant in its task. 5v is just a blanket promise. Real V_r limits vary from not much to over 100v.

1
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