This is the central documentation page for NCH8200HV High Voltage module.
How to Test a Nixie tube using the NCH8200HV
Check your soldering. Use a multimeter to check the continuity between [Vin and GND], [Vout and GND}. Make sure they are not short.
To keep the NCH8200HV minimal in footprint, the SHDN (Shutdown) pin is not added to the module.
If you would like to use this feature, here is how to modify it.
Cut the trace on the PCB board as shown in the image below.
The pin (shown in green) on the IC is the SHDN pin. It may be used to enable/disable the 170V output.
When you need to drive more tubes, you may use multiple NCH8200HV modules.
Keep in mind that, do NOT tie the 170V output together.
Each NCH8200HV can power up some of the tubes, as shown below.
In certain circumstances, the module may generate a high pitch/frequency noise, audible to human ears. It can be suppressed, if not completely eliminated, by the following method.
This will efficiently suppress the noise level.
This method has also been used by Dalibor Farny in his Puri clock (Link) currently in mass production.