A high-voltage amplifier takes a lower voltage input signal -- e.g. from a function generator of some sort -- and amplifies it to a high voltage. In this case, the output range is -200V to +200V. High voltage amplifiers can be used for a variety of applications, such as driving piezos, or digital microfluidics electrodes.
This board was created in KiCad 6.0.4.
This project can be dangerous. 200V is sufficient to kill you under the right conditions. Even under the best conditions, it can give you a painful shock. You should not build this unless you know what you're doing. If you do build this, you should handle it with caution. Be very careful about what you touch when it is energized. Don't touch it with both hands simultaneously. If you don't have to have it exposed, enclose it. Insulate any wiring connected to the HV output.
This design uses the Apex PA88 high-voltage op-amp. These are fairly expensive (~$250) at mouser, but I was able to find one for much cheaper on Ebay when I built this. It also has a switching power supply which generates the positive and negative high voltage rails from a 9V input.
It can be operated at 100V, or 200V, based on whether the jumper JP1 is shorted.
The gain (Output voltage / control voltage) is adjustable from 15.9x to 60.2x, using the potentiometer. At maximum gain, an input of 3.3V will provide an output of 199V.
When idle, it draws about 40mA when operating at 100V, and about 80mA at 200V. It should be able to source about 4mA, although I have not tested under this kind of load. For my application the current draw is much less. At some point I may stress test it, but I am putting it off in case this test proves to be destructive!
I have provided some mesh files for a 3D printable enclosure. It requires some M3 heat inserts (like these) and 18-23mm long M3 screws (like these) to assemble. The STLs can be found in the enclosure directory.
