# How do you calculate voltage peaks after a tube full-wave rectifier?

Discussion in 'Electronic Basics' started by at, Aug 29, 2004.

1. ### atGuest

How do you calculate the voltage peaks of voltage coming out of a full-wave
rectifier tube?

If 230V 50Hz AC has voltage peaks approx 1.41 times the average voltage, the
voltage peaks seen by the rectifier tube would also be like that. But what
happens in the rectifier? How high are the peaks coming out of it?
The rectifier in question is a GZ34 tube, and it has a voltage multiplier of
1.3, so output voltage (DC) is 1.3 times input voltage (AC), so if 230VAC
average goes in, the output is 299 average. But how high are the voltage
peaks that come out of the tube?

Thanks!

-at

2. ### Michael A. CovingtonGuest

The voltage drop through a tube rectifier under light load is practically
zero.

3. ### petrus bitbyterGuest

According to the datasheet
http://www.drtube.com/tubedata.htm
the peak voltage depends on the current. If you have no or a very small
load, the peak voltage will be about 1.41 * Vin. Vin being the RMS value of
a sine wave AC source. The current will highly depend on the load and the
smoothing filter. This and the accurancy of the tube parameters make a
general calculation scheme less usefull. (Although you can make one if you
want.)

petrus bitbyter

5. ### Kevin AylwardGuest

"How do you calculate voltage peaks after a tube full-wave rectifier?"

Just run some spice simulations. It will take you < 1sec per run.

Hint: SuperSpice has the GZ34 tube model and a symbol for it.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

6. ### atGuest

Thanks.

This will help.

-at