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Combining state-of-the art HV Mosfets with a photodiode array optocoupler allows for a simple linear series regulated high voltage supply. The proof-of-pronciple setup covers the ranges for 0..+1400V and 0..-1400V with the ability to supply several 100 microAmperes. The residual rms ripple/noise is < 100mV.

To prepare for a project to build a general purpose high accuracy high-voltage supply suitable various experiments I wanted to explore the possibilities to make a simple to build high voltage (1.5kV) series regulator that works for both polarities.
The presented project addresses this challenge using state-of-the art HV-Mosfets and a not-so-common optocoupler as essential ingredients. Using these, the rest of the regulation circuitry is straightforward and simple.

In order to make a simple low-noise high voltage supply for some experiments with photomultipliers and other radiation detectors I grabbed some parts that were laying around (2 print transformers 230/9V, 6VA, a bunch of 10mF/450V capacitors and 1N4007 diodes). This is enough to experimentally create the raw HV voltages in the range of ±1600V. For stabilization and control using a MOS-FET as series voltage regulator, two dedicated special modern components had to be purchased: a 1700V SIC-Mosfet (MSC750SMA170B, ~5Eur) and a optocoupler (TLP3905, ~1 Eur) that supplies the voltage from a series array of photodiodes as output (up to 7V) that is able to directly drive the MOS_FET. These two latter make the rest of the schematics quite simple and safe.
The corresponding regulation allows to setup positive and negative (using two branches) voltages for 0 to about 1400V (max 0.5mA) with a residual noise floor < 100mV rms.

More details and results arre described in the attached file: HV_regulated_supply1.pdf.