I read to use a digital potentiometer but I'm not sure what to get. I want to replace the 30k pot on a motor I have with an arduino so I can control the speed with arduino.
What's the cheapest way to do this? The potentiometer I'm using now is just a cheap 30k and it works great.
notsolowki:
I read to use a digital potentiometer but I'm not sure what to get. I want to replace the 30k pot on a motor I have with an arduino so I can control the speed with arduino.What's the cheapest way to do this? The potentiometer I'm using now is just a cheap 30k and it works great.
It's more about what the current pot does to control motor speed. Knowing that makes things much easier. A schematic of the speed controller would be nice. Type of motor? Type of control? Just knowing it is a 30K pot isn't enough. What power is the pot rated at? The cheapest way to do it is the way you see it being currently done. Now if you want to automate that exactly how the pot is being used is important.
Ron
Voltage is also important (most digital pots are rated for low voltage, low current, and low power). Plus if this is an AC motor running from the power line, the digital pot the low-voltage circuitry has to be electrically isolated.
...The sad truth is, in most cases you can't "simply" replace a mechanical pot with a digital pot. More often, the whole circuit has to be re-designed & replaced. 
I will check how much current is flowing through the pot and what voltage. We are actually working with DC sorry I didnt mention that.
Unfortantualy there is not schematic and the speed controller is covered in epoxy.
Okay so its actually 50k pot. Totally disconnected between 2 wires is full speed. When I check the current in amps on a dead short is only showing 0.01. A dead short of the pot wires is fully off.
When I check the voltages between the two wires it shows 10.8DC.
It almost seems like pulling it high shuts off the circuit. I wonder of I could get away with a mosfet in replace of the pot.
I'm not sure what current the pot is rated at but it's one of those real cheap ones that probably handles very little current. The pot dont get warm either so I'm assuming its low low current
What do you think? I didnt want to use the arduino directly as I know that's not possible but what should I use to replace the pot?
Next I would look at common to the pot wiper and see if they just use it as a 0 to some voltage out but from your description it sounds like one side of the pot is tied to the wiper. The idea being trying to figure out how the pot is used in the circuit.
Ron
I tested with wires from the pot to the earth ground but it didnt show anything except a few mv.
What I tried was using my rigol programmable dc power supply to send voltage down those wires where the pot is. 11v is max speed and I can step it down down .5v at a time until 1v is lowest speed. I was using a 100ma current protector but it only used 10ma max.
notsolowki:
What I tried was using my rigol programmable dc power supply to send voltage down those wires where the pot is. 11v is max speed and I can step it down down .5v at a time until 1v is lowest speed. I was using a 100ma current protector but it only used 10ma max.
Based on that, and I may well be wrong on this, I don't see an Arduino as a viable solution. The main problem being while an Arduino and similar micro-controllers have ADC they don't naively have DAC. You would need a DAC and a DAC with about a 12 volt reference. The DAC in turn being driven by the Arduino or similar. Not knowing the motor or the signal applied to the motor it gets hard to make any good suggestions. I understand it's a DC motor but there are a few methods of speed control used on DC motors. That makes it hard to give a suggested solution.
Ron
How could I use an arduino 0-5v to control12 volts to the pot wires.
I need the output to be .7 to 10.8dc to the wires. What transistor or mosfets would be suitable for this? I tried a 2n3906 but the leakage didnt allow me to full stop the motor
I was looking at this but It looks like it wont work because it only supports up to 5.5v?
I'm just trying to find the easiest fastest way to do this. I could handle the code i think but I'm not sure where to go from here. I would actually prefer to use esp8266 which brigs us down to logic level. Please help me here
Direct short of the pot wires @ 10.8v is fully off. Open circuit is fully on. Or .7v which ever comes first. I dont see any common wires I could really tap into but I do have a 12v wire I could use.
Ditch the controller and substitute your own.
Okay this is actually for a light. I have found a hardware schematic please have a look at it. It looks like you dimm it multiple ways. Sorry I dont know why I said it was a motor forgive me.
Anyways I didnt know this schematic existed until now.
What are my options to control that dimmer circuit with an esp8266?
it seems like it would be really easy if i could find a digital pot with the capability to handle 11v. All i see are 5v versions. I have read a lot of forums about dimming the Meanwell Led Driver with an arduino but they all end without a solution.
I would like to control these drivers with an esp8266 or esp32. i want to be able to fully turn on this driver so loosing 10 or 5% output from the driver because my signal is 1v short is not going to cut it. i tried using a NPN transistor with DIM+ connected to collector, DIM- and Supply ground to emitter. when i apply voltage to the base i can use my programmable dc power supply to adjust the brightness but i have to stay between 600-650mv supply to the base. just changing it 1mv makes a big difference in output.
notsolowki:
I have read a lot of forums about dimming the Meanwell Led Driver with an arduino but they all end without a solution.
Look again.
I gave some, on this forum.
notsolowki:
i tried using a NPN transistor with DIM+ connected to collector, DIM- and Supply ground to emitter. when i apply voltage to the base i can use my programmable dc power supply to adjust the brightness but i have to stay between 600-650mv supply to the base. just changing it 1mv makes a big difference in output.
Of course it does. The transistor amplifies, and makes it into a digital on/off signal.
Try connecting the lab supply (0-10volt) directly to the DIM pins.
If you want to dim with a 'voltage' from an Arduino, then you could smooth a PWM signal, and amplify to 10volt with an op-amp.
The common way for LED drivers, is with a PWM signal (invisible/fast on/off control).
An opto coupler could be safer for that than just a transistor.
Not sure what you're trying to do.
Motor?
What kind.
Leo..
Wawa:
Look again.
I gave some, on this forum.
Of course it does. The transistor amplifies, and makes it into a digital on/off signal.
Try connecting the lab supply (0-10volt) directly to the DIM pins.
If you want to dim with a 'voltage' from an Arduino, then you could smooth a PWM signal, and amplify to 10volt with an op-amp.The common way for LED drivers, is with a PWM signal (invisible/fast on/off control).
An opto coupler could be safer for that than just a transistor.Not sure what you're trying to do.
Motor?
What kind.
Leo..
Yes every thread about this LED Driver dimmer had you in there helping out. I got the idea for the transistor in one of the threads you replied in. I'm sorry this thread must be a confusing mess by now. Let me try this again.
i have a Meanwell 600 driver that is dimmable one of 3 ways,pwm@10v ,0-10v linear, 100k pot.
I want to control the dimming of it with "preferably" esp8266 or esp32. i have read about the optocoupler but i have never used one. I have to make sure i get full output from the driver which ever way i end up going.
I would prefer to be able to go down to 0.7v and up to atleast 10.8v with the circuit controlled by an esp. Im not sure which way is best i have little experience in all of this. I have lots of transistors and mofests including TIP120'S.
if i feed power in from the dc programmable 0.7v is threshold for full off and 10.8 is fully on. everywhere in between is dimming. I really really want to be able to dim with an esp. i have located a 12.4vdc and ground wire on the ballast that i can use for whatever so a 1.5v voltage drop shouldn't hurt me too bad.
Do you think this circuit could work with a esp8266? Minus the arduino voltage in and pot
it would be nice to make use of something i already have. but i dont know if a transistor or mosfet is the answer
notsolowki:
I want to control the dimming of it with "preferably" esp8266 or esp32.
That's all you need. No Uno, no 12volt supply, no LM317.
Just power an ESP breakout board of your choice with a 5volt cellphone charger with USB connector.
And use a small signal NPN transistor, with base CL resistor, across the DIM pins.
Or an opto coupler, for an extra safety layer.
The ESP32 has more I/O than the ESP8266, and could be more stable (pot and PWM).
No experience there, because I only have used the ESP8266 (Wemos D1 mini).
Leo..
