Power transformer from Tek545 'oscope

[jim]

Hi,

I've 3 power transformer from Tektronix 545 oscilloscopes.
I figured out the specs for the heater winding (by means of
the handbook/service manual).
But I have no clue for the high voltage current ratings.
Does any of you have any info on these trannies ?
There are 100+ tubes in this scope so I think they are
pretty beefy.

Thanks,
Jim

[Stocker]

??? you have the specs there! what is the question?

[jim]

The current ratings of the HV-windings ???

Jim

[Tom Bavis]

Doesn't the schematic show the load on each? I recall that each winding had 10 Ohm power resistors which were used as current test points.

If not, you can measure the DC resistance and allow 2W dissipation for each. So a 10 Ohm winding can handle 450 mA (.45^2 * 10 = 2.02W). Maybe a little more if some windings are left unloaded.

Naturally you can series connect windings for the voltage you want - Tektronix did.

A stereo 6550 amp would be no problem with one of these...

[Brian Beck]

I've also got a few salvaged Tek scope transformers, sitting on a shelf awaiting a new call to service. I don't know that this will help you a whole lot, but I've attached the schematic for the 545 supply if you don't have it already. You can get at least some idea of each winding's prowess by looking at the regulator that goes with each one.

Tek 545 power supply

[jim]

You can get at least some idea of each winding's prowess by looking at the regulator that goes with each one.

Yes, that's what I also did to have an idea of each winding.

If not, you can measure the DC resistance and allow 2W dissipation for each. So a 10 Ohm winding can handle 450 mA (.45^2 * 10 = 2.02W). Maybe a little more if some windings are left unloaded.

Is this a sort of "rule of thumb" ?

I'm going to measure the windings and calculate, then compare these findings with the schematic.

Thanks,
Jim

[DigitalJunkie]

Those old Tek trannies are great for projecs,and experimenting.I've got a couple here..Loads of windings to play with!

Humm.. 545 huh? Whats the number on the tranny? (120-xxx or something?)

*digs around*

Dean Kidd: dektyr(at)teleport(dot)com
or
Stan: w7ni(at)easystreet(dot)com

Can probably help you out,they've helped me find specs for Tek trannies before.

Another good place to check would be:
http://groups.yahoo.com/group/TekScopes/

[astouffer]

This may be of some help

http://www.fairradio.com/0120037.htm

[jim]

Originally posted by astouffer
This may be of some help

http://www.fairradio.com/0120037.htm

Thanks, this data gives some indication although I have another transformer.

Jim

[Brian Beck]

And here's the power supply schematic to the Tek 531/541. It is very similar to the 545 power supply I posted above. Which means that if we can believe the Fair Radio ratings provided for the 531 transfomer, the 545 rating ought to be close to the same. Note also that in the 531/541 schematic, voltage drops across the 10 ohm resistors are given.