Hi Charles thank you for your response. The resistor is not hot at all. 81.6 degrees. Its 9 ma. for the inverter. The rest of the power is simply the switcher losses. The .31 watts is the 120 vac consumption not the 3500V inverter. I actually use 2 X 220 ohm resistors in series as thats what I had but it could be 470. Its not critical. Regards Paul
On Thu, Aug 5, 2021 at 6:51 PM Charles Steinmetz <[email protected]> wrote: > paul wrote: > > > Leave just the 3500V supply run. Disconnect it from the internal power > add > > a resistor and cap powered by a external switching wallwort in the 1 watt > > range. Brand new meanwell units are $11. These are medical grade not > that > > its required. The resistor is about 470 ohms a 1/4 watt. Dropping 24V to > > 19V. Use a 470 uf cap on the side of the resistor connected to the 3500V > > supply. Ground the negative to the chassis so the I pump meter works. > > I may have misunderstood what you are doing, but a 470 ohm resistor > dropping 19v to 24v will draw from 40 to 51mA, and will dissipate from > 0.75W to nearly 1.25W. > > If this is the real operating condition, it's not a happy place for a > 1/4 watt resistor. You'd really want a 2W or greater resistor there, > with some good ventilation around it. > > Best regards, > > Charles > > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send > an email to [email protected] > To unsubscribe, go to and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
