[sdiy] Siel OR400 Transformer needed
Stromeko at nexgo.de
Sat Jul 27 12:56:45 CEST 2013
[sorry if you get this twice, mail client is acting up]
On Saturday 27 July 2013, 05:05:33, M Maeghan Skala wrote:
> The voltage readings I gave off were from the spare PSU board.
Thanks, that explains a lot. So, the board is slightly dodgy from age or
abuse, but it is likely that the IC are still functioning.
> I went to my local electronics store tonight and purchased some new
> components … frankly, i wouldn't mind building a whole new power supply.
> I got some LM317's and LM337's and some bridge rectifiers, since I didn't
> have any adjustable regulators in my inventory or any bridge rectifiers …
> i know off the top of my head the sill cruise uses lm317's, and LM337's to
> supply +12/-12, and +6/-6 VDC to the board … maybe I could copy that
That would probably work, but I'm not familiar with that circuit.
> this would be a quick and easy re-build if it wasn't for the µA79MG &
> µA78MG voltage regulators being 4-pin … can i make the current board work
> with connecting some leads? or should i start drawing up a new PSU board
> to etch later today?
If you go for a new board, then maybe you can find one that you only need to
wire the connectors for. But given your spare board, I'd try to salvage it
first: Check if the regulator IC are still functioning by putting a 100k
resistor in parallel to each resistor Ra3..Ra10 (with small croco clamps or
micro-hook clamps so that you have your hands free) and check that the
respective output voltage changes by about 5% to 10%. Do this first with no
load and then load each output and do it again (the loaded voltage should
only be slightly smaller). If that works, simply get a new bridge rectifier
(the schematics show a 80V/1A most likely, you can substitute a 2A model in
the same package, but don't go for much higher voltage), the load caps
(1000µF/35V or 50V axial, same size) and the filter caps (1µF/25V radial)
plus all the resistors Ra3..Ra10 (as 1/2W metal film and better than 5%
precision). If you replace these you should then have a good as new PSU
board. Be careful when unsoldering the old parts and double check the
poarities of the parts.
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+
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