Newbe here. Don't know jack about electronics, but I have a deep desire to learn about them.

Working on a project that has two 12v dc vibrator motors, each independently controlled with PWM controller to create a Interference pulsator modulation between the two vibrators, similar to a Nobra Twincharger.

I would like to add a master control potentiometer to control the two PWM controllers so that once I get the proper frequency interference of each motor, I can then use the master pot to increase or decrease the amplitude of both units. Clear? Probably not. Here's a diagram:

 

First post wouldn't let me add more photos, but this is what I would like to use. I am open to suggestions if you guys know of anything better.

 

I also have two of these PWM controllers that have the 3 wire outputs:

 

You can't use a double/ganged pot?
Max.

 

MaxHeadRoom - Thank you for the answer, but again, newbe here. I don't know. Can I? Would I install that before the PWM controllers or on their output to the motors? Across both of the PWM potiometers? This is why I came to this forum. So I can get help from experienced people.

 

If you have two PWM controllers controlled from two separate pots, you can get dual/ganged pots that share the same shaft, if this is what you are looking for?
Max.

 

Ok, I think I understand. Would that still allow each separate motor to still then be controlled independently? Would there be 3 pots total?

 

You cannot increase the amplitude of the PWN signal, its stated at 0-5V, 36mA max
You can how ever, add additional circuitry to achieve this

 

Your motor is rated at 7-13V max so you will need a couple of mosfets anyway