Author Topic: BK Precision 1735(Non-A) PSU Recap Question - SOLVED  (Read 1348 times)

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Offline t1dTopic starter

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BK Precision 1735(Non-A) PSU Recap Question - SOLVED
« on: May 29, 2019, 10:40:55 am »
I am considering replacing the caps in my PSU, as it is decades old. In doing my homework before starting the project, I came across these photos of the PCB. Some of the caps have connections that I do not know. I expected just two pins for each cap, but...
- C1 and C2 have four, maybe six, solder points. My guess is that two holes are bodged for a pin spacing that was not that drilled originally. And, that the remaining two might be for a jumper wire, between two pours... But, this would mean the jumper is under the cap?
- C3 and C4 have two, maybe three, solder points. My guess is that one hole was bodged for a pin spacing that was not that drilled originally.
- C9 looks as I would have expected, two pins.

All of these caps have a "SSS" silk-screened between two of the pins. I could use some help with what this symbol means and its orientation, too.

This is the Bottom PCB Photo. Top of PCB photo and Schematic are on the following posts.

« Last Edit: May 29, 2019, 12:49:56 pm by t1d »
 

Offline t1dTopic starter

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Re: BK Precision 1735(Non-A) PSU Recap Question
« Reply #1 on: May 29, 2019, 10:41:37 am »
Photo 2

« Last Edit: May 29, 2019, 10:43:28 am by t1d »
 

Offline t1dTopic starter

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Re: BK Precision 1735(Non-A) PSU Recap Question
« Reply #2 on: May 29, 2019, 10:42:10 am »
Schematic
« Last Edit: May 29, 2019, 10:44:43 am by t1d »
 

Offline Jay_Diddy_B

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Re: BK Precision 1735(Non-A) PSU Recap Question
« Reply #3 on: May 29, 2019, 12:16:35 pm »
T1D and the group.

Those extra pads are so BK can build the 1711 & 1715 (60V)models on the same PCB.
In these models the capacitors are in series and resistor R1B an R1C are installed.

On the 30V models the capacitors are in parallel.

On these models the electrolytic capacitors will be rotated 90 degrees.



C1B and C2B designations are used.



Regards,
Jay_Diddy_B
« Last Edit: May 29, 2019, 12:21:07 pm by Jay_Diddy_B »
 
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Offline t1dTopic starter

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Re: BK Precision 1735(Non-A) PSU Recap Question
« Reply #4 on: May 29, 2019, 12:29:51 pm »
Hi, Jay. Thanks for the info. You really are a knowledgeable guy and I always appreciate your input. Can you tell me what the "SSS" means? Is it a designater for the pin orientation for the specific model?
 

Offline t1dTopic starter

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Re: BK Precision 1735(Non-A) PSU Recap Question
« Reply #5 on: May 29, 2019, 12:48:15 pm »
The "SSS" silkscreen is just a different way to indicate that it is an electrolytic. Maybe used by the Japanese?
https://electronics.stackexchange.com/questions/105441/what-is-the-symbol-on-the-supply-voltage-that-looks-like-a-shaded-in-capacitor
 


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