arduino for field inversion


I'm a life-long hack at simple circuits and Arduino is my first foray into microcontrollers. This project is for SCIENCE on a shoestring. Here's my project: I want to perform FIGE (field inversion gel electrophoresis). Don't know FIGE? Not important. I have a regulated, switchable power supply that produces DC (variable from 10-300 volts, 4-400 mA). All I want is a circuit that will invert the polarity of this nice smooth current on command from a program I load onto the chip.

I've been considering just using a solid-state relay that uses the +5v current to switch.

So, questions.

One, does my approach sound appropriate/ideal? (fast, cheap, effective)

Two, any suggestions about suppliers for an appropriate SSR?

Three, my goal is to interfere with the current as little as possible except for the inversion. Any suggestions for how to avoid spikes during the switches? Caps across the relay leads?

Thanks for any input. May Science smile upon you.


What you've described sounds fine but I'm not sure about spikes with solid state relays.