RK07 repairable?

From: Jochen Kunz <jkunz_at_unixag-kl.fh-kl.de>
Date: Sat Jan 18 02:30:01 2003

On 2003.01.17 20:35 Tony Duell wrote:

> The DEC 'bricks' -- the H744, etc, regulators -- used in the 10.5"
> PDP11/34 box are relatively friendly to work on. They are swtichers,
> but they start from a 30V AC input (from a large mains transformer --
> an isolating transformer).
The owner showed me already a big transformer (should be around 200..400
VA) from the PSU. He also said that the PSU is modular and one of the
modules is broken. An other reason why I an expecting a /34.

> So they're not as dangerous to work on as most SMPSUs.
Well, I have a isolating transformer...

> And they're fairly simple electronically.
Hmm. I have no clue about SMPSUs. Good reason to learn more about them.
Especially as there is a SGI Personal Iris 4D35 with broken PSU waiting
for repair also. Fortunately I know a electronics designer who has
designed several SMPSUs. So I am able to get some help.

> On the other hand, the PDP11/44 supply is painful.
Heared about that.

> smoothing capacitors -- the later are coke-can sized (!).
I have a 78 mF (mili, not micro) capacitor from a Printronix chain
printer. It is about 1' tall and 5" in diameter...
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/
Received on Sat Jan 18 2003 - 02:30:01 GMT

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