Extending/Halving the time of a timing motor, 120V, 60Hz

[pben613]

Hello, I was wondering if anyone can point me in the right direction in adjusting the speed of a timing motor. This motor is part of a cam timer for an oven, similar to a dryer. I was hoping to slow the motor down to change a 1 hour cycle to a 2 hour cycle.

The timer motor is 120vac 60 Hz 2 wire AC motor (3 watt).

Thanks,

Ben

 

[FvM]

Most likely it's a synchronous motor. Driving it with 30 Hz 60 VAC should work.

 

[pben613]

Most likely it's a synchronous motor. Driving it with 30 Hz 60 VAC should work.

Thanks, I just wasn't sure how to accomplish it. It is a synchronous motor. My first idea got to complicated. I was going to use a cycle timer to stop and start the motor every 10 sec.

I was hoping there was a better idea floating around.

Am I looking at VFD or is there something even simpler for a 3 watt application?

Thanks,

Ben

- - - Updated - - -

Do you think I could put a delay-on relay on the timer motor to extend the oven cycle? Where the timing motor doesn't start for a set period of time.

Thanks,

Ben

 

[BradtheRad]

This schematic can divide incoming mains AC frequency by two (in theory).



The control circuit will be tricky.

Somewhere it will have a flip flop (which implies a low voltage device). The input will be triggered by the 60 Hz sinewave.
The flip flop divides-by-two. The output is applied to the mosfet gates. This requires it be stepped up to 170 V or so.

So I made it easy on myself by using a 'generic clock', alternating between 0 and 170 V.

I don't know for certain that the above will work. It's just a concept.

 

[FvM]

It is a synchronous motor. My first idea got to complicated. I was going to use a cycle timer to stop and start the motor every 10 sec.

I appreciate the idea. The effort is most likely considerable smaller than for a VFD.