I would like to identify the state of 3 switches, sw 1, 2 & 3 and when
power is supplied to a fan …… so 4 indicators – assume these would be
LED. I.1 – I.4

Sketch is attached. https://flic.kr/p/2phwkJ8

Controller is self contained providing Blue tooth, Wireless, time &
temperature functions, thermocouple inputs etc .. they all work,
providing the 2 ‘conditional’ inputs are satisfied. Providing variable
voltage supply to the fan.

Input 1 – is satisfied when switch one is closed, this is a simple 12V
DC cct

Input 2 - is satisfied when Switch 2 & 3 are closed
The output voltage is then provided to the fan, this is a variable
voltage from 0 to 12V DC

What I want to ‘add’ are 4 indicators, showing state of each switch, and
when there is any power to the fan.
So I would need a way of identifying any voltage present and changing to
an on or off ‘switch indication’
Trying to think of an easy way …. I could use a voltage comparator to
detect a difference between fan driver voltage & ground, but as there
are 2 switches as well …. Assume then its 3 comparators, so getting
complicated.
The ‘comparator modules’ are an option https://tinyurl.com/54e89cp6
Hopefully someone can can up with something simpler than 3 of these.

The switched are spst plungers, with no option to change them to give
another set of contacts.

Anybody any suggestions, the simpler the better - no Ardui or similar …
just need a few thoughts to start me off

On 23/11/2023 21:31, Sargan wrote:

> Trying to think of an easy way …. I could use a voltage comparator to
> detect a difference between fan driver voltage & ground, but as there
> are 2 switches as well …. Assume then its 3 comparators, so getting
> complicated.

Are you sure that the speed control is a variable dc voltage and not
pulse width modulation?

Maybe
https://www.nutsvolts.com/magazine/article/led-graph-circuits

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 23/11/2023 21:31, Sargan wrote:
> I would like to identify the state of 3 switches, sw 1, 2 & 3   and when
> power is supplied to a fan …… so 4 indicators – assume these would be
> LED.   I.1 – I.4
>
> Sketch is attached.   https://flic.kr/p/2phwkJ8
>
> Controller is self contained providing Blue tooth, Wireless, time &
> temperature functions, thermocouple inputs etc .. they all work,
> providing the 2  ‘conditional’ inputs are satisfied.  Providing variable
> voltage supply to the fan.
>
> Input 1 – is satisfied when switch one is closed, this is a simple 12V
> DC  cct
>
> Input 2 - is satisfied when Switch 2 & 3 are closed
> The output voltage is then provided to the fan, this is a variable
> voltage from 0 to 12V DC
>
>
> What I want to ‘add’ are 4 indicators, showing state of each switch, and
> when there is any power to the fan.
> So I would need a way of identifying any voltage present and changing to
> an on or off  ‘switch indication’
> Trying to think of an easy way …. I could use a voltage comparator to
> detect a difference between fan driver voltage & ground, but as there
> are 2 switches as well …. Assume then its 3 comparators, so getting
> complicated.
> The ‘comparator modules’ are an option    https://tinyurl.com/54e89cp6
> Hopefully someone can can up with something simpler than 3 of these.
>
> The switched are spst plungers, with no option to change them to give
> another set of contacts.
>
> Anybody any suggestions, the simpler the better  - no Ardui or similar …
> just need a few thoughts to start me off
>
>
>
>
Do what I did, design and build your own, which has its own LEDS built in...

--
Climate is what you expect but weather is what you get.
Mark Twain

On 23/11/2023 21:31, Sargan wrote:
> I would like to identify the state of 3 switches, sw 1, 2 & 3   and when
> power is supplied to a fan …… so 4 indicators – assume these would be
> LED.   I.1 – I.4
>
> Sketch is attached.   https://flic.kr/p/2phwkJ8
>
> Controller is self contained providing Blue tooth, Wireless, time &
> temperature functions, thermocouple inputs etc .. they all work,
> providing the 2  ‘conditional’ inputs are satisfied.  Providing variable
> voltage supply to the fan.
>
> Input 1 – is satisfied when switch one is closed, this is a simple 12V
> DC  cct
>
> Input 2 - is satisfied when Switch 2 & 3 are closed
> The output voltage is then provided to the fan, this is a variable
> voltage from 0 to 12V DC
>
>
> What I want to ‘add’ are 4 indicators, showing state of each switch, and
> when there is any power to the fan.
> So I would need a way of identifying any voltage present and changing to
> an on or off  ‘switch indication’
> Trying to think of an easy way …. I could use a voltage comparator to
> detect a difference between fan driver voltage & ground, but as there
> are 2 switches as well …. Assume then its 3 comparators, so getting
> complicated.
> The ‘comparator modules’ are an option    https://tinyurl.com/54e89cp6
> Hopefully someone can can up with something simpler than 3 of these.
>
> The switched are spst plungers, with no option to change them to give
> another set of contacts.
>
> Anybody any suggestions, the simpler the better  - no Ardui or similar …
> just need a few thoughts to start me off
>
>
>
>
Yes get real. Ardui or similar is cheap and flexiable and when you don't
like the way it works you can change it.

Dave

On 24/11/2023 10:56, David Wade wrote:
> On 23/11/2023 21:31, Sargan wrote:
>> I would like to identify the state of 3 switches, sw 1, 2 & 3   and
>> when power is supplied to a fan …… so 4 indicators – assume these
>> would be LED.   I.1 – I.4
>>
>> Sketch is attached.   https://flic.kr/p/2phwkJ8
>>
>> Controller is self contained providing Blue tooth, Wireless, time &
>> temperature functions, thermocouple inputs etc .. they all work,
>> providing the 2  ‘conditional’ inputs are satisfied.  Providing
>> variable voltage supply to the fan.
>>
>> Input 1 – is satisfied when switch one is closed, this is a simple 12V
>> DC  cct
>>
>> Input 2 - is satisfied when Switch 2 & 3 are closed
>> The output voltage is then provided to the fan, this is a variable
>> voltage from 0 to 12V DC
>>
>>
>> What I want to ‘add’ are 4 indicators, showing state of each switch,
>> and when there is any power to the fan.
>> So I would need a way of identifying any voltage present and changing
>> to an on or off  ‘switch indication’
>> Trying to think of an easy way …. I could use a voltage comparator to
>> detect a difference between fan driver voltage & ground, but as there
>> are 2 switches as well …. Assume then its 3 comparators, so getting
>> complicated.
>> The ‘comparator modules’ are an option    https://tinyurl.com/54e89cp6
>> Hopefully someone can can up with something simpler than 3 of these.
>>
>> The switched are spst plungers, with no option to change them to give
>> another set of contacts.
>>
>> Anybody any suggestions, the simpler the better  - no Ardui or similar
>> … just need a few thoughts to start me off
>>
>>
>>
>>
> Yes get real. Ardui or similar is cheap and flexiable and when you don't
> like the way it works you can change it.
> Raspberry Pi Pico W is cheaper than arduino, and a Pi ZeroW is far more
flexible at the same price.

> Dave

--
“The urge to save humanity is almost always only a false face for the
urge to rule it.”
– H. L. Mencken

On 24/11/2023 11:13, The Natural Philosopher wrote:
> On 24/11/2023 10:56, David Wade wrote:
>> On 23/11/2023 21:31, Sargan wrote:
>>> I would like to identify the state of 3 switches, sw 1, 2 & 3   and
>>> when power is supplied to a fan …… so 4 indicators – assume these
>>> would be LED.   I.1 – I.4
>>>
>>> Sketch is attached.   https://flic.kr/p/2phwkJ8
>>>
>>> Controller is self contained providing Blue tooth, Wireless, time &
>>> temperature functions, thermocouple inputs etc .. they all work,
>>> providing the 2  ‘conditional’ inputs are satisfied.  Providing
>>> variable voltage supply to the fan.
>>>
>>> Input 1 – is satisfied when switch one is closed, this is a simple
>>> 12V DC  cct
>>>
>>> Input 2 - is satisfied when Switch 2 & 3 are closed
>>> The output voltage is then provided to the fan, this is a variable
>>> voltage from 0 to 12V DC
>>>
>>>
>>> What I want to ‘add’ are 4 indicators, showing state of each switch,
>>> and when there is any power to the fan.
>>> So I would need a way of identifying any voltage present and changing
>>> to an on or off  ‘switch indication’
>>> Trying to think of an easy way …. I could use a voltage comparator to
>>> detect a difference between fan driver voltage & ground, but as there
>>> are 2 switches as well …. Assume then its 3 comparators, so getting
>>> complicated.
>>> The ‘comparator modules’ are an option    https://tinyurl.com/54e89cp6
>>> Hopefully someone can can up with something simpler than 3 of these.
>>>
>>> The switched are spst plungers, with no option to change them to give
>>> another set of contacts.
>>>
>>> Anybody any suggestions, the simpler the better  - no Ardui or
>>> similar … just need a few thoughts to start me off
>>>
>>>
>>>
>>>
>> Yes get real. Ardui or similar is cheap and flexiable and when you
>> don't like the way it works you can change it.
>> Raspberry Pi Pico W is cheaper than arduino, and a Pi ZeroW is far more
> flexible at the same price.

Possibly. I was actually going to suggest a PIC chip as these are also
cheap...

>
>
>> Dave
>

Dave

On 24/11/2023 10:37, The Natural Philosopher wrote:
> On 23/11/2023 21:31, Sargan wrote:
>> I would like to identify the state of 3 switches, sw 1, 2 & 3   and
>> when power is supplied to a fan …… so 4 indicators – assume these
>> would be LED.   I.1 – I.4
>>
>> Sketch is attached.   https://flic.kr/p/2phwkJ8
>>
>> Controller is self contained providing Blue tooth, Wireless, time &
>> temperature functions, thermocouple inputs etc .. they all work,
>> providing the 2  ‘conditional’ inputs are satisfied.  Providing
>> variable voltage supply to the fan.
>>
>> Input 1 – is satisfied when switch one is closed, this is a simple 12V
>> DC  cct
>>
>> Input 2 - is satisfied when Switch 2 & 3 are closed
>> The output voltage is then provided to the fan, this is a variable
>> voltage from 0 to 12V DC
>>
>>
>> What I want to ‘add’ are 4 indicators, showing state of each switch,
>> and when there is any power to the fan.
>> So I would need a way of identifying any voltage present and changing
>> to an on or off  ‘switch indication’
>> Trying to think of an easy way …. I could use a voltage comparator to
>> detect a difference between fan driver voltage & ground, but as there
>> are 2 switches as well …. Assume then its 3 comparators, so getting
>> complicated.
>> The ‘comparator modules’ are an option    https://tinyurl.com/54e89cp6
>> Hopefully someone can can up with something simpler than 3 of these.
>>
>> The switched are spst plungers, with no option to change them to give
>> another set of contacts.
>>
>> Anybody any suggestions, the simpler the better  - no Ardui or similar
>> … just need a few thoughts to start me off
>>
>>
>>
>>
> Do what I did, design and build your own, which has its own LEDS built
> in...
>
>
The controller is already in place so just want to 'supplement; with LED

On 24/11/2023 10:56, David Wade wrote:

> Dave
don't want to use Ardui

On 11/23/2023 4:31 PM, Sargan wrote:
> I would like to identify the state of 3 switches, sw 1, 2 & 3   and when power is supplied to a fan …… so 4 indicators – assume these would be LED.   I.1 – I.4
>
> Sketch is attached.   https://flic.kr/p/2phwkJ8
>
> Controller is self contained providing Blue tooth, Wireless, time & temperature functions, thermocouple inputs etc .. they all work, providing the 2  ‘conditional’ inputs are satisfied.  Providing variable voltage supply to the fan.
>
> Input 1 – is satisfied when switch one is closed, this is a simple 12V DC  cct
>
> Input 2 - is satisfied when Switch 2 & 3 are closed
> The output voltage is then provided to the fan, this is a variable voltage from 0 to 12V DC
>
>
> What I want to ‘add’ are 4 indicators, showing state of each switch, and when there is any power to the fan.
> So I would need a way of identifying any voltage present and changing to an on or off  ‘switch indication’
> Trying to think of an easy way …. I could use a voltage comparator to detect a difference between fan driver voltage & ground, but as there are 2 switches as well …. Assume then its 3 comparators, so getting complicated.
> The ‘comparator modules’ are an option    https://tinyurl.com/54e89cp6
> Hopefully someone can can up with something simpler than 3 of these.
>
> The switched are spst plungers, with no option to change them to give another set of contacts.
>
> Anybody any suggestions, the simpler the better  - no Ardui or similar … just need a few thoughts to start me off

1) Sense current flow in wire, make a status that way.
Ground referenced sense resistor, ground referenced capable opamp.
2) Extra contact pair on switch (which you have dismissed as a solution).
3) Optoisolator, which works as long as the load will share 25mA with you.
4) Tachometer output on fan. Use a series resistor and a zener, to condition
the tacho output for input to your controller. You can use a monostable
and some logic gates, to measure the period between fan pulses (instead of
measuring the period in software with your controller), and
that is how you "guarantee a minimum fan speed is met".

With a 4538, I can build just about any timing function you can think of.
I used to use those for bench automation, so I could go home while a lab
circuit did repetitive procedures.

https://en.wikipedia.org/wiki/List_of_4000-series_integrated_circuits

The original ones run over a wide supply range (5V to 15V?)

https://www.jameco.com/z/CD4538B-Major-Brands-IC-CD14538B-DUAL-MONOSTABLE-MULTIVIBRATOR-MC14538CP-_13653.html

Fans come in the following configurations:

2-wire Basic fan, runs 5V to 12V or runs 7V to 12V. You should not feed
them 3V, as they may draw some amount of current (stall) and not spin
if you don't meet the fan_min input. As you lower the voltage, the
current flow should increase a bit. Test for this! Your driver must be
able to supply stall current, if you insist on driving at 3V.

3-wire Two pulse per revolution tachometer output. Based on output from
brushless DC coil drive.

4-wire Fan now receives a constant 12V power. The PWM signal, uses pulse width
to indicate what the desired fan speed is. At "0 PWM", an Intel Spec
fan continues to spin at fan_min speed. At "0 PWM", a non-Intel fan
would spin at zero speed. The PWM signal operates at a high enough
frequency, so that there is no acoustic effect coming from the fan hub.
(PWM fans sometimes "sound different" than 2-wire or 3-wire fans.)

Paul

On 24/11/2023 17:19, Sargan wrote:
> On 24/11/2023 10:37, The Natural Philosopher wrote:
>> On 23/11/2023 21:31, Sargan wrote:
>>> I would like to identify the state of 3 switches, sw 1, 2 & 3   and
>>> when power is supplied to a fan …… so 4 indicators – assume these
>>> would be LED.   I.1 – I.4
>>>
>>> Sketch is attached.   https://flic.kr/p/2phwkJ8
>>>
>>> Controller is self contained providing Blue tooth, Wireless, time &
>>> temperature functions, thermocouple inputs etc .. they all work,
>>> providing the 2  ‘conditional’ inputs are satisfied.  Providing
>>> variable voltage supply to the fan.
>>>
>>> Input 1 – is satisfied when switch one is closed, this is a simple
>>> 12V DC  cct
>>>
>>> Input 2 - is satisfied when Switch 2 & 3 are closed
>>> The output voltage is then provided to the fan, this is a variable
>>> voltage from 0 to 12V DC
>>>
>>>
>>> What I want to ‘add’ are 4 indicators, showing state of each switch,
>>> and when there is any power to the fan.
>>> So I would need a way of identifying any voltage present and changing
>>> to an on or off  ‘switch indication’
>>> Trying to think of an easy way …. I could use a voltage comparator to
>>> detect a difference between fan driver voltage & ground, but as there
>>> are 2 switches as well …. Assume then its 3 comparators, so getting
>>> complicated.
>>> The ‘comparator modules’ are an option    https://tinyurl.com/54e89cp6
>>> Hopefully someone can can up with something simpler than 3 of these.
>>>
>>> The switched are spst plungers, with no option to change them to give
>>> another set of contacts.
>>>
>>> Anybody any suggestions, the simpler the better  - no Ardui or
>>> similar … just need a few thoughts to start me off
>>>
>>>
>>>
>>>
>> Do what I did, design and build your own, which has its own LEDS built
>> in...
>>
>>
> The controller is already in place so just want to 'supplement; with LED

It will be more work to modify it than to start from scratch.

My controller went live two hours ago, so far so good.

--
"The most difficult subjects can be explained to the most slow witted
man if he has not formed any idea of them already; but the simplest
thing cannot be made clear to the most intelligent man if he is firmly
persuaded that he knows already, without a shadow of doubt, what is laid
before him."

- Leo Tolstoy

On 24/11/2023 17:20, Sargan wrote:
> On 24/11/2023 10:56, David Wade wrote:
>
>> Dave
> don't want to use Ardui

Well try praying to god then

--
In a Time of Universal Deceit, Telling the Truth Is a Revolutionary Act.

- George Orwell

On 24/11/2023 11:13, The Natural Philosopher wrote:
> On 24/11/2023 10:56, David Wade wrote:

>> Yes get real. Ardui or similar is cheap and flexiable and when you
>> don't like the way it works you can change it.
>> Raspberry Pi Pico W is cheaper than arduino, and a Pi ZeroW is far more
> flexible at the same price.
>
>
>> Dave

Both require knowledge & skills I don't have, and expensive to turn ion
or off 4 LEDs
My thoughts are use an LM319 voltage comparator to get me a 12V signal
anytime there is any Fan +ve
Remove switches from controller and use them to power DPST reed relays
... outputs complete fan circuit and drive LED

Cost is under a Tenner

Looking like:https://flic.kr/p/2phFn7G

On Friday, 24 November 2023 at 18:45:40 UTC, Sargan wrote:
> On 24/11/2023 11:13, The Natural Philosopher wrote:
> > On 24/11/2023 10:56, David Wade wrote:
>
> >> Yes get real. Ardui or similar is cheap and flexiable and when you
> >> don't like the way it works you can change it.
> >> Raspberry Pi Pico W is cheaper than arduino, and a Pi ZeroW is far more
> > flexible at the same price.
> >
> >
> >> Dave
> Both require knowledge & skills I don't have, and expensive to turn ion
> or off 4 LEDs
> My thoughts are use an LM319 voltage comparator to get me a 12V signal
> anytime there is any Fan +ve
> Remove switches from controller and use them to power DPST reed relays
> .. outputs complete fan circuit and drive LED
>
> Cost is under a Tenner
>
> Looking like:https://flic.kr/p/2phFn7G

Your schematics don't display.
A LED just needs a resistor from switched 12v to indicate.
A comparator is another way, where needed.
A transistor can be used as the comparator, a resistor divider on the input setting the threshold.
For mains voltages a neon is easier.
There are plenty of free parts in e-waste.

On 24/11/2023 18:31, The Natural Philosopher wrote:
> On 24/11/2023 17:20, Sargan wrote:
>> On 24/11/2023 10:56, David Wade wrote:
>>
>>> Dave
>> don't want to use Ardui
>
> Well try praying to god then
>

I did and he said don't use a sledgehammer to crack a nut ....

After suggestions here and elsewhere I can achieve what is needed with 2
x DPST reed relays and a pre-built voltage comparator module or even
this simple voltage detector
https://www.eleccircuit.com/simple-level-voltage-detector-using-lm741/

I don't have experience to use an open source electronic prototyping
platform such as Arduino, I'm not knocking it but don't have time to
learn to use it.
Plus I can achieve what I want for under a tenner.

If I was building my own system controller from scratch that would be a
different proposition, but the existing one is under warranty for a
year, so will keep with it for now.

On 24/11/2023 18:01, Paul wrote:
> On 11/23/2023 4:31 PM, Sargan wrote:

> Fans come in the following configurations:
>
> 2-wire Basic fan, runs 5V to 12V or runs 7V to 12V. You should not feed
> them 3V, as they may draw some amount of current (stall) and not spin
> if you don't meet the fan_min input. As you lower the voltage, the
> current flow should increase a bit. Test for this! Your driver must be
> able to supply stall current, if you insist on driving at 3V.
>

Thanks its simple 2 wire 12V DC

On 11/25/2023 3:19 PM, Sargan wrote:
> On 24/11/2023 18:01, Paul wrote:
>> On 11/23/2023 4:31 PM, Sargan wrote:
>
>> Fans come in the following configurations:
>>
>> 2-wire   Basic fan, runs 5V to 12V or runs 7V to 12V. You should not feed
>>           them 3V, as they may draw some amount of current (stall) and not spin
>>           if you don't meet the fan_min input. As you lower the voltage, the
>>           current flow should increase a bit. Test for this! Your driver must be
>>           able to supply stall current, if you insist on driving at 3V.
>>
>
>
> Thanks its simple 2 wire 12V DC

With a three wire fan, the options for the third wire
are "stall" status or "tacho 2PPM output". With the tacho output,
you can actually determine the current rate of rotation.
Some Panaflo fans had a "stall" output (fans intended for instrumentation
chassis applications, tend to use "stall", while fans for computers
use "tacho" instead).

Computer fans use tacho. they measure the period between pulses,
then invert, to get RPM.

Fans without tacho, can be optically monitored. They make various
kinds of transmitters and receivers, where the blade rotating
through the optical path, yields a signal. A good optical monitor,
used encoded transmission, and at the receiver, the receiver
is "synchronous", which wipes out all of the "noise" in the
received signal. That gives a relatively clean indication of
blocked or not-blocked optical path.

But buying a fan with tacho, is cheaper than retrofitting a
sensor the hard way.

You CAN solder a transistor to the PCB inside the fan hub
and make your own third-wire tacho signal.

https://hw-by-design.blogspot.com/2018/07/adding-tachometric-output-to-cheap-pc.html

Paul