PL504 PSU

159

01:47:52

The one on the left is for Europe (230V/50Hz)
The one on the right is for USA (120V/60Hz) 

The 120ohm resistor should be 10W. 
All caps should be rated at 450V 
The PL500/PL504 parameters are:

Va - 275V (static) 550V (dynamic) 7kV (pulsed peak) 
Ik - 250mA

That are the important parameters for designing the power supply. We only need the static voltage required. The dynamic voltage is when the anode is transformer coupled. So we set the Plate voltage at 275V and the cathode current at 250mA. I'm not even sure that these parameters are optimal, because the maximum power dissipation stated in the datasheet is around 22W, but at 275V/250mA the dissipation comes to around 70W. That's a very large discrepancy. Just stick to more normal tubes like EL84. I made an excellent 15W amplifier with 2 EL84 tubes in a push pull topology. I can upload the circuit i designed somewhere if you're interested. 

published 9 years ago

giomix

9 years ago

Whitch is the scope of 56 ohm resistor? Voltage drop is around 12 volt. Do you need to limit current through the coil ?

WTFCircuit

9 years ago

I guess it's the inductor internal resistance

WTFCircuit

9 years ago

I have to make a vacuum tube tesla coil with a pl504 (actually a el504, but the only difference between the two is the filament voltage and current) and I have to use a voltage multiplier to step up the voltage to at least 600Vdc directely into the tube anode.

thebugger

9 years ago

Tesla coils don't need an amplifying device. The 56ohm and 180ohm resistors are much needed to minimize the ringing. They're close to the critical dampening value.

WTFCircuit

9 years ago

If the multiplier is not needed why everybody uses it?

hurz

9 years ago

Buggzy seems to be electro shocked the last time he was not listening to me as i warned him to better use a galvanic separation. Now its nice to see all this 1:1 transformer. Would be nice if Igor could make a second different looking "ground" symbol we can use on secondary side to emphasis its not earth ground!

thebugger

9 years ago

No, I've always known that you have to separate the mains ground, and I've always suspected why, but an isolation transformer is often expensive and bulky, and that's why they often skipped it in old tv's and radios making them essentially shock hazardous. I too would like a few ground symbols. There should be an earth ground, a chassis ground and a signal ground according to me, but one ground works too. In reality using the same ground as earth ground can lead to ground loop problems.

WTFCircuit

9 years ago

What is the ground loop?

thebugger

9 years ago

It'll be easier if i make a tutorial. Search for Ground Loops 101

Lucan01

9 years ago

Link circuit here please :)

thebugger

9 years ago

http://everycircuit.com/circuit/5928224299679744

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.