Hey guys, I've been reading through the sticky and had an idea for the blower and didn't know if it would work well or not. I just bought a little bench grinder that actually has a variable speed dial on it... is there any reason something like this wouldn't work on our blower motors? I was thinking a single relay connected to the same wire that activates the blower speed control switch and then just mount the dial on the dash. If that would work, anyone know where I could get the little variable voltage dial?

 

Your Bench Grinder is probably and AC unit and most of the speed controls are simply a Triac like in a light dimmer, the best way to install a speed control would be to use a Pulse Width Modulated controller and as the name implies the wdith of the 12 volt pulse it modulated or turned off and on many times per second to control how fast the motor will turn.

With a PWM controller the motor always has full voltage so that it will have its maximum torque from the first revolution all the way up to full speed.

I use these controllers for robotic controls to control traction motors.

An example of these are on electric wheelchairs except they use 2 of them and are connected with an H-controller to allow the use of a joystick.

Simple.
Jim

 

sounds like it will be more expensive than a couple relays and some wire... maybe I should just stick to that!

 

It would be a little more expensive but you would have a lot more control over the blower speed.

I have 3 of these PWM controllers integrated into some of my projects at the present time.

With a PWM controller the motor has full torque from the instant it starts to turn all of the way to full speed.

http://www.diverseelectronicservices...ontroller.html

Jim