timed circuits with electromagnets

[PaulBrooke]

Hey guys,
I'm wanting to make a circuit with 4 electromagnets running on a 12v power supply, but I would like each electromagnet to turn on and off one after the other, so that iron fillings move on a surface above from the first to the last electromagnet.
Is there a way to do this manually or with Arduino?
Thanks!
Paul

 

[Harald Kapp]

Welcome to EP.

Manually: e.g. by using a rotary switch with four positions. By moving the dial on the switch the magnets become subsequently powered.
Using Arduino: Easily. You'll need drivers (transistors) to power the magnets as the Arduino cannot provide enough output power (unless your magnets are very weak). Connect each driver to one output of the Arduino with proper series resistors to limit base current. Activate and deactivate the outputs in the proper sequence by a short program.

 

[Minder]

Do you want variable rate?
If using a PIC or Arduino, you could look at logic gate Mosfets, no base currents.
M.

 

[AnalogKid]

If using a CD4017 Johnson counter, no programming.

What are the electromagnet coil resistance and voltage?

ak

 

[WHONOES]

I agree. Using a Johnson counter should be easy, just need a frequency source again easy, and mosfets on the outputs.