How can I build a 12V DC motor controller for my fishing pole?

[yrliner]

I have attached a 12v DC electric drill moter to a fishing pole.
I need a 12v dc motor controler or PWM that will allow me to cut the rpm's down from 550 rpm to about 20 to 100 rpm. less then 20 would work better for bottom fishing.
I believe a PWM would work but I am not sure as to a schematic I can use to build one.
Any ideas or input would help. I am not wanting to buy something. I want to build it with my son. it's our project together. thanks for the help. Just F.Y.I we are makeing this so I can go fishing independtly I only have the use of 1 arm.

 

[davenn]

hi there
welcome to PF :)

do some google searching PWM+H-bridge+motor+circuits

you should come up with lots of ideas :)

cheers
Dave

 

[yrliner]

No will not need a H-bridge It is only going to turn 1 way.

 

[milesyoung]

What you want can be done very simple and cheap using a 555 IC, a power transistor and a few passive components. It's probably one of the most well-documented hobby projects around since so many start out building exactly that circuit.

Like davenn suggested, do a Google search for something like "555 pwm motor" - you should find plenty of material.