Quote Originally Posted by jstrack2 View Post
It only uses about 50 mA at 5V.
That looks really simple and could be very effective. However, I think you should modify it to work around the current modulation scheme the peachy uses for mirror positioning. This would need to use FM, because AM is already used using it or PM would just be too complicated and costly in my opinion. Also, using FM directly should translate into an up and down motion in the magnet, so it should be able to easily control the actuation directly. Problem is, the line level of most audio output is very low, so I think there's really no way of getting around an op amp or some other kind of amplification, which also means you need a DC bias, and as far as I know there's basiaclly no way to get around this without using requiring separate USB power, batteries, or a transformer. A transformer could be used to directly power the bias from the audio output, but then you're at least doubling the cost and probably quite a bit more ( think) to achieve the Voltage and current simultaneously. So, in my opinion USB power would be the way to go here since it's already connected to audio and practically every source of audio is going to have some sort of USB connection. I'm not sure what kind of power mico and mini USB provide, though. So, powering this entirely from a device that doesn't have a standard USB connection might be a little bit tricky.

As for the magnet itself, it would probably help to have some sort of support system inside the pipe as well to provide some surface the magnet can press against when it is up so that the viscosity, pressure, and flow rate of the resin does not affect the orientation of the magnet very much either. Any ideas there?