Virtual Battery PSU

[Tyimo]

Hi!

Could somebody tell me how to adjust this circuit for lower output voltage??
e.g. 180Vdc and 100Vdc? It has now 270Vdc on the output. (info from Andrea Ciuffoli"s great site)
Greets:
Tyimo

 

[Mark Johnson]

Since zener diode D5 is a voltage clamp which protects MOSFET Q1's gate-to-source thin oxide, I would have expected that Q1's source would be on the output side (connected to R6), while Q1's drain would be on the input side (connected to R1).

However the schematic is drawn the other way, with Q1's source = input, and Q1's drain = output, and clamp diode D5 from gate to drain. Jeepers!

 

[Tyimo]

However the schematic is drawn the other way, with Q1's source = input, and Q1's drain = output, and clamp diode D5 from gate to drain.

Yes, but I don't know what do you want to say????

 

[Mark Johnson]

I worry that the schematic contains at least one error and possibly more.

 

[Zen Mod]

please , complete this completely non-commercial survey and then you can see our circuit , without deliberate errors

 

[Tyimo]

What?!?

 

[Tyimo]

I tried to get contact with Andrea Ciuffoli, but He didn't answer yet.

 

[audiodesign]

Hi,
This circuit can work without any changes from 100V to 350V

to support 450V voltage use IRF840

 

[audiodesign]

You can use better diodes like UF4007 1A or UF5407 3A if current is more than 0.2A

 

[Tyimo]

Hi!
Thanks!
Do I need to adjust or change some value if I need to get 180Vdc?
What should be the input Vac in this case? I don't know the voltage drop of your circuit.

Merry Christmas!

Tyimo

 

[audiodesign]

If the DC voltage on C5 is 200V

Vout = 200 * ( R2 / ( R2 + R1 )) - Vgs = 200 * ( 100K / ( 100K + 22K)) - 4 = 200 * 0.82 - 4 = 159V

about VAC = 1.2 + 200 / 1.41 = 143V

 

[audiodesign]

VAC = 160V
VC5 = 224V
VOUT = 179V

The final output voltage depend in part by the current so probably you need to adjust R1 or R2.

 

[Tyimo]

Thanks a lot!!!!!!!

 

[Zen Mod]

virtual battery , all the way from time of Technics coining da name , is just fancy name for cap multiplier , with added resistive divider for establishing output voltage range

in other words - neither proper cap multiplier nor proper reg