how do i rotate a 3 v dc motor 90 degrees at a time?

I would like to use a limit switch to stop the motor and a push button switch to start it again and move it to the next stop. There will be a mechanical arm at each 90 degree position to trigger the limit switch.

YOu need a circuit like a windshield wiper. You could try this one, I designed for a fellow 'ibler.

This was designed to turn a shaft once, all you need to do is make it do it 4 times per rev.

reland (author)  steveastrouk5 years ago
Thanks, I have revised it a bit for just what I have on hand. Here are some photos.
It works without the relay and the IC, I just need the transitor and two single pole switches.
I have one more query. Is there a way to run it with a non-pushbutton type switch.
Lets say the user flicks the switch completing to circuit, the motor turns 90 degrees trips the limit. Then to continue to the next 90 degs they hit the switch again, this time the circuit as drawn is incomplete. Would i need to add another transistor to complete the circuit between the non-limit switch and motor, right?

Thanks for the help!