Help with my Transformer - vibrating

[Brit01]

Hi guys,

Something strange is happening with my psu

Just stoppped working and blew the fuse on the primary.

I disconnected the psu, replaced the fuse, and placed a light bulb between the connections on the secondary.

Light bulb lit fine.

Now I replaced the rectifier, checked all connections, and then re-attached and powered up. The tranny shakes like a earthquake!! Immediately switched it off, checked everything and tried again. again the same vibration and no B+ voltage.

What's going on?

 

[Brit01]

Update:

I tried using my SS rectifier with the tranny and still it vibrates like crazy.

What's happening with the tranny? Has it died? Strange that it still illuminates the light bulb.

 

[whitelabrat]

Something is shorted, but I don't think it is the transformer. That's my first guess.

 

[chris661]

Same problem in the physics lab. The one we were using was very old, so it vibrated itself off the desk.

I'd try a new one.

Chris

 

[Shoog]

Excessive current draw from a short somewhere. If the transformer isn't giving off rank smelling smoke then its probably somewhere else.
Start by looking for blackened resistors - especially cathode resistors.

Shoog

 

[Brit01]

Had a good night sleep and checked everything in the morning. seems to be my tube power supply.

Tried a new SS power supply and everything works fine.

Very strange, checked everything visually on Bas's psu and everything looks undamaged. Have to do some probing.

Cheers

 

[Brit01]

Checking the circuitry:

D2 on Bas's psu is reading both ways

Blown diode here?

 

[richwalters]

A shorted diode creating half wave seems a possible cause.
On the otherhand; some years ago I came across a sim problem to find a 110V transformer wired for a 230V supply. Over voltage leading to core-saturation can also cause sim noises. Check primary wiring config.

richy

 

[Brit01]

Turned out to be one of the diodes! Swapped it and all works fine now

 

[richwalters]

Although you may have found the fault; there may be an underlying reason behind this: It may repeat.
Is surge current (input inrush) into cap input filter too high ?
Too high reverse peak volts for diode? (Vrrm ratings)
Mechanically busted.

An anti surge fuse used in primary ?

richy

 

[Brit01]

I've been experimenting with various designs of circuitry. First testing with psu2 but this is just approx I know.

I'm suspecting it was the 6080 I was testing. bought a load of new tubes last week and was testing a lot of them. Think I overloaded it with the 6080.

I need to get a new tranny built to run the heavy current 6080's for a future project.