[time-nuts] Strange E3610A PSU - Old revision

[Adrian]

There appears to be some massive contamination on the board, apparently 
not only from a leaked electrolytic cap. It looks much like some unknown 
liquid flooded a large area of the board and dried.

I do not see any reworked solder joints on the board, so the 'unusual' 
components have to be original to the unit. Do not attempt to change the 
circuit (replace components with values from a schematic that does not 
match the given circuit exactly), otherwise you'll end up in a mess. You 
may perform the service note changes though, given you check carefully 
if they work for your unit. Especially the voltage overshoot issue 
should be easy to check in advance.

The 12/91 date code on the transformer (unfortunately, the serial number 
is still undisclosed) indicates a very early example of the E3610A that 
was actually introduced in the 1992 catalog.

As by the 1992 catalog, there is a 10-turn voltage pot and a 1-turn 
current pot. More recent versions have 10-turn current pots as does mine 
from 1998. Also, it has U2 = LM340T (!), U4 = LF442CN, U5 = LM393N, U1 = 
LF411CN, U3 = LM336.

Hope that helps.

Adrian


cfo schrieb:
> I just bought a E3610A PSU on ebay , as defective.
>
> Main problem right now is ... This seems to be an older revision
>
> And has other comp values , than the "Schematic on the net"
>
> Comp    Item		      - Org Value	      - Inserted
> value
> -----   -------------------     ---------------------   -----------------
> R19     CC frontpanel Pot     - 10 turn 10k 	      - 1 turn 10K
> U2      12v Regulator         - MC7812CT              - LM340T12
> U4      Current OpAmp         - LF442CN               - LM1458N
> U5      CC/CV Indicator       - LM393CN               - LM393N
> U1      Voltage OpAmp         - LF411CN               - LM741EN
> U3      Volt Ref              - LM336-5.0 5.0v        - LM329 6.9v
>
> PCB     PCB number            - ??
>
> C7	Pos. REF CAP          - 330uF 50v             - 330uF 50v
> C13	Neg. REF CAP          - 470uF 50v             - 330uF 50v
>
> I posted some pics here.
> http://tinyurl.com/cn9p4s9
>
>
> Does anyone have a schematic of a E3610A , that might have ie. LM1458 in
> it or a 6.9v Ref , instead of a 5v Ref ?
>
> Tia
> CFO Denmark
>
>
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