Integrating AC motor with DC Logic

Thread Starter


Joined Apr 10, 2014
Hello I'm a newb here I just joined the site. I have been a student at a Technical Institute for about 1 year and am working towards a robotics automation degree. The things I have been learning I am itchy to start a project of my own. But still have lots to learn...

So what I am trying to do is integrate an AC motor into a DC logic circuit. I just recently found a motor that will work for my application...I think... The motor is 115VAC synchronous geared with cw/ccw control. What I would like to do is be able to communicate to the motor using DC logic to tell it when to turn on/stop/cw/ccw. I was told that there is relays that can be communicated to using DC but keeps the AC seperate from the DC Circuit...True?

any tips and advice on what to use would be greatly appreciated.

thank you



Joined Jul 18, 2013
First what is the nature of the synchronous motor, AC stepper motor or shaded pole etc?
Either way, relays can be used for control, the advantage of AC stepper is very precise stop/start/reverse/position.
A shaded pole synchronous require an initial 'kick' mechanism to rotate in the desired direction.
Any reason you are using an AC synchronous motor, apart from being available?


Joined Mar 14, 2008
If you really need to use a AC motor and it will be turned on and off frequently then the safe way to control it from a DC signal is to use a Solid-State-Relay (SSR). This provides complete isolation between the DC control input and the AC output. For infrequent operation you could use a standard mechanical relay.