I have a dc motor that I use for building fishing rods. I run it in both directions now with a switch & potentiometer manually. I purchased a PWM & foot pedal to replace that and would like the ability to use both. Any ideas how to wire this foot pedal into the PWM to be able to use either of them? DPDT switch somehow? I’m baffled on how to accomplish this.

 

Yeah DPDT switch would solve the direction but I am not sure if your pedal can substitute the potentiometer without additional stuff.
Is the pedal just a big potentiometer or it has some other stuff inside?
Measure resistance between "5V" and "P" while pressing the pedal (pedal disconnected). Does it change? What are the minimum and maximum values?

Also, what is the value of the resistance of your potentiometer on the controller, between pins 1 and 3?

 

Welcome to AAC!
Your Hall-effect pedal puts out a voltage but your PWM controller is designed to respond to the potentiometer resistance. Depending on its construction, the controller might not like a voltage applied to its control input.
Can you post the full technical spec of the controller?

 

OK for some stupid reason my brain processed "HALL" pedal as "WAH" pedal and I thought it means it is potentiometer-based (facepalm).

 

Yeah DPDT switch would solve the direction but I am not sure if your pedal can substitute the potentiometer without additional stuff.
Is the pedal just a big potentiometer or it has some other stuff inside?
Measure resistance between "5V" and "P" while pressing the pedal (pedal disconnected). Does it change? What are the minimum and maximum values?

Also, what is the value of the resistance of your potentiometer on the controller, between pins 1 and 3?

The switch in the image is actually controlling the direction now. Essentially it's doing everything I need, I just want to add a pedal to control variable speed with my foot but still maintain the ability to turn it on & control the variable speed from the potentiometer. I forgot to bring it this morning to test today, so I may run & grab it later. I'll try to get those values, thanks for your help. I was thinking about just building a circuit with what I have in the images, then another circuit with the foot pedal, DPDT switch for direction and then have another DPDT switch that I can toggle between the 2. I just had a feeling there was a much easier way of handling this.

 

I think the easiest way to do is just change the rotary pot with a pedal like this:



Just check the value of the rotary pot..

If you really want to use the pedal you bought, and want to make it work just for fun, the approach should be:

Use an op-amp as comparator, on one input you bring your output of the pedal, and on the other input sawtooth signal generated by NE555. When the sawtooth is higher than the pedal, output is ON, when it is lower, output is OFF.. voala.. PWM.. you probably would have to bring that signal into MOSFET driver for your motor.

Anyway, either different pedal with your controller, or your pedal with DIY controller.

 

Welcome to AAC!
Your Hall-effect pedal puts out a voltage but your PWM controller is designed to respond to the potentiometer resistance. Depending on its construction, the controller might not like a voltage applied to its control input.
Can you post the full technical spec of the controller?

Sadly, what's in those images are all I have. This was a quick cheap purchase for testing and I got what I paid for. I had replied to meth that I considered trying to just keep 2 separate circuits using a switch to flip between the 2. For the pedal, would I need some other controller? I'm not sure how the pedal actually works in relation to increasing voltage, etc.

 

OK for some stupid reason my brain processed "HALL" pedal as "WAH" pedal and I thought it means it is potentiometer-based (facepalm).

No worries, this is all new to me and I'm learning. I have an electronics degree from 30 years ago & never utilized it, so I'm a little green on remembering all of this.

 

I think the easiest way to do is just change the rotary pot with a pedal like this:

View attachment 352435

Just check the value of the rotary pot..

If you really want to use the pedal you bought, and want to make it work just for fun, the approach should be:

Use an op-amp as comparator, on one input you bring your output of the pedal, and on the other input sawtooth signal generated by NE555. When the sawtooth is higher than the pedal, output is ON, when it is lower, output is OFF.. voala.. PWM.. you probably would have to bring that signal into MOSFET driver for your motor.

Anyway, either different pedal with your controller, or your pedal with DIY controller.

Could a switch & potentiometer also be put into the circuit with this new pedal elsewhere so I could just run this without having to use the pedal, a constant on?

 

Everything else can stay as it is, we are just talking about the controller and the pot.

 

Everything else can stay as it is, we are just talking about the controller and the pot.

Yea, I was just curious if there's a possibility to have it both ways. Have it setup with the potentiometer and switch that I can control fwd & rev and also a method to have the foot pedal that I can control fwd & rev. There's time I need to run it constantly varying the speed & direction, but not wanting to have to hold the pedal down as I'm moving around sanding, etc. I believe I want more than can be accomplished easily without some complex circuity.

 

I think the easiest way to do is just change the rotary pot with a pedal like this:

View attachment 352435

Just check the value of the rotary pot..

If you really want to use the pedal you bought, and want to make it work just for fun, the approach should be:

Use an op-amp as comparator, on one input you bring your output of the pedal, and on the other input sawtooth signal generated by NE555. When the sawtooth is higher than the pedal, output is ON, when it is lower, output is OFF.. voala.. PWM.. you probably would have to bring that signal into MOSFET driver for your motor.

Anyway, either different pedal with your controller, or your pedal with DIY controller.

Of course that pedal would be a few weeks lead time, just my luck. And I can't find any others, within a reasonable budget, that ships sooner.

 

I just thought of something, I somehow bought 2 of the PWM's. Couldn't I replace the potentiometer with a pedal on one of them, then use a DPDT switch on the outputs of both PWM's to toggle between the 2? That would allow me to use the pedal if needed, then just turn it on with the other one by flipping the switch?

 

Didn't the PWM controller come with istructions for use?

 

Didn't the PWM controller come with istructions for use?

No, besides the plastic it was in, that was it. No instructions or specs whatsoever.

 

Yeah DPDT switch would solve the direction but I am not sure if your pedal can substitute the potentiometer without additional stuff.
Is the pedal just a big potentiometer or it has some other stuff inside?
Measure resistance between "5V" and "P" while pressing the pedal (pedal disconnected). Does it change? What are the minimum and maximum values?

Also, what is the value of the resistance of your potentiometer on the controller, between pins 1 and 3?

I ohm’d out the pedal with no resistance from any pins. The pot itself shows around 4 ohms all the way turned up. The pedal has 3 wires with pins going to a contractor plate that is near a sliding plate operated by the pedal. The 2 plates appear to get further away as it moves with the pedal.

 

I wrote that reply before I realized it is not pure potentiometer, but it has a hall sensor instead.
As I mentioned your best solution is to buy that aliexpress pot pedal.

 

1) What voltage is your power supply to the motor?
2) Do you have a 5V supply for the Hall pedal?
3) If you have a voltmeter, connect the pot, controller, motor supply and controller as per post #1. Don't connect the Hall pedal for now. Power up the assembly and measure the voltages at the three pot terminals relative to the supply negative terminal, with the motor running at about half speed. Post the values.

 

I wrote that reply before I realized it is not pure potentiometer, but it has a hall sensor instead.
As I mentioned your best solution is to buy that aliexpress pot pedal.

No worries, I appreciate the help.

 

1) What voltage is your power supply to the motor?
2) Do you have a 5V supply for the Hall pedal?
3) If you have a voltmeter, connect the pot, controller, motor supply and controller as per post #1. Don't connect the Hall pedal for now. Power up the assembly and measure the voltages at the three pot terminals relative to the supply negative terminal, with the motor running at about half speed. Post the values.

Thanks Alec_T, I will try that. I did check the output voltage to the motor but didn't write them down. I will check the POT when I get a chance this afternoon. I didn't even consider that, I just checked the output voltage. Thank y'all both for sticking with me here, it's appreciated.