2N3055 failure (power supply)

I tracked down the fault in a failed power supply to a failed 2N3055
power transistor. It's conducting from C->B in a gang with 4 other
transistors driven by a TIP31. The net result was that the failure
caused the supply to jump to 22V+, far higher than its typical max
voltage, and with no current limiting. Are there any obvious mods
I should consider while I'm fixing it?

___
|
TIP31 | ___
LM723 ___ |/ |
[Vout>-|___|-o-----| |
22R | |> o---o---o---o---o
| | | | | | |
| ___ | | | | | |
'-|___|-o |/ |/ |/ |/ |/ 2N3055
2k2 '-----|---|---|---|---|
|> |> |> |> |>
| | | | |
.-. .-. .-. .-. .-.
| | | | | | | | | |
0.1R | | | | | | | | | |
5W '-' '-' '-' '-' '-'
| | | | |
o---o---o---o---o---->>>

(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

--
Ben Jackson AD7GD
<ben@xxxxxxx>
http://www.ben.com/
.

Relevant Pages

  • Re: 2N3055 failure (power supply)
    ... power transistor. ... The net result was that the failure ... This gives the gang of 3055s a slow turn off and a voltage overshoot when a .load is step reduced. ...
    (sci.electronics.design)
  • Re: 2N3055 failure (power supply)
    ... power transistor. ... It's conducting from C->B in a gang with 4 other ... transistors driven by a TIP31. ... The net result was that the failure ...
    (sci.electronics.design)