4Ke PSU shot, replacing with a modded 5K PSU

[PMcC]

Hi Xmax, good to hear from you...I am sooooġ happy to have metering back, I know we all trust our ears more than anything else but just for that DAW playback line up, super.

When I get a clear minute I'll draw up a schematic and upload here with actual voltages at the key points. By the way if found 240V low wattage halogen lamps a great way of loading the hi volt supply for bench testing.

Back soon

Pat

[PMcC]

Hi All,

Fact...32 plasma modules draw a maximum current of 164mA from the 250VDC supply.

How do I know this?

By taking voltage readings across the two 4.7R current sharing resistors that are in series with the two power Mosfets of the supply I built to replace the failed 4K unit, I have been able to calculate this current.

The voltages across these resistors are reassuringly similar, 384.89mV and 389.6mV. This equates to approximately 82mA in each resistor.

To draw the greatest current, I needed to light up every segment of every plasma module. This meant max'ing out all VCA faders with the metering switched to monitor VCA positions.

Clearly plasma metering is no power hungry monster, nice to know.

I've included a couple of pics, ok the HV supply build has a prototype look but it works well and being completely separate and independent of the main 5K supply, if the worst does happen, it can easily be dispatched to the 'bench' for fixing while the session can continue.

[PMcC]

The voltage across one 4.7R current sharing resistor...all plasmas flat out.

[PMcC]

Early doors for the assembly of the HV regulator power components...two International Rectifier high voltage Mosfets (TO220 package type) plus their associated 4R7 current sharing power resistors (ceramic), all four mounted on an 'L' extrusion bracket.

Pat