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DIY High Voltage PSU

Some time ago I’ve found on eBay a couple of HV generator modules made by FuG Elektronik GmbH, model HCN 20 EM-2000. This kind of modules coud be simply modified to be used as variable HV power supply.

Quick fact-sheet with pinout: 13822-01doc

  • Positive HV output
  • variable output from  to 2000V
  • maxiumum ouptput current 10mA with overcurrent protection
  • 31 pin back connector
  • 24Vcc supply
  • 5k linear multiturn potentiometer for voltage selection
  • 0-10V out voltage monitor, 10V = 2000V out
  • 0-10V out current monitor, 10V = 10mA out

The mod consist into simply reencase it, add a 24V supply and an Arduino-driven LCD wich shows voltage and current.

I’ve started with removing the aluminium case and put all the electronics into a nice tabletop ABS enclosure with handle them, I’ve made a front panel with LCD, 5k pot. knob, HV output SHV connector. On the back panel I’ve putted a fuse holder with power switch and mains cable socket.

The HV it’s further filtered by a big R-C-R-C-R stage for leveling andswitching noise cleaning. For R i suggest to use 100kOhm 1W resstor. For C use as much capacity you have in the range 10-100nF with working voltage over 2000V.

Into the picture you can clearly see the Arduino proto board that drives the LCD, the troidal transformer that supply the 18Vac—>24Vdc after rectification and fltering needed by the module. The big black block under the LCD it’s a 5k trimmer “Helipot” 11 turns. Extremply precise device, buy one if you can fnd it even if it costs aprox. 20€.

The current and voltage output are aquired by Arduino analog inputs by a couple of voltage dividers. Them divide the 0-10V monitor output by a factor of 2 in order to fit the Arduino’s 0-5V maximum acceptable input range. A small nF range capacitor it’s in parallel to the second resistor to GND to smooth the ADC readings by adding some hysteresis.

 

Here the arduino code, it’s self-explaining: 2kv hv

Here the PSU module schematic: 13822-01

Connections:

  • 5k pot. (26) +10V (29) whiper (24) GND
  • (1-2) GND (3-4) +24V input
  • (8) V-Mon output 0-10V
  • (10) I-Mon output 0-10V