12v VFD circuit

[lostnconfused]

I am trying to come up with a simple cheap circuit that will switch a 12v 2 amp load, from about 20 Hz to .2 Hz. It needs to switch positive / negative (ac) and have a ramped function of about 10 seconds to go from these two low frequency’s. Initially, just to try it out (and if simpler) a pot turned by hand can be the control. Icing on the cake would be the ability to variably bias the output, say about 60% positive 40% negative. Square wave also a plus. All the above is +/- about 100% of the stated values. Thanks for any possible help -Tom

 

[itsmoked]

At these voltages you would probably be best served by a classic H-Bridge or a Half-H-Bridge. A pot is not going to directly work. For a one-off I would use a PIC STAMP or similar to generate a PWM based switching signal to the Bridge from the pot or easier from an UP and DOWN set of buttons.

For a product I would toolup a micro system from scratch to do the whole thing and anything else needed.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com