Author Topic: AOIP PJ6301 schematic  (Read 2368 times)

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Offline tatel

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Re: AOIP PJ6301 schematic
« Reply #25 on: March 09, 2024, 10:38:02 pm »
I have one last thing to fix, the binding posts of the device are in really bad shape and needs to be replaced, but i can't find anything  that can be adapted
(Attachment Link)
The back thread is 4mm, quite long, and they allow a wire to be clipped. Thay allow to use safety plugs.
Anyone have seen something similar?
Thanks!

I have... but it comes on an AOIP resistor decade box. Identical.
 
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Offline masterx81Topic starter

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Re: AOIP PJ6301 schematic
« Reply #26 on: March 09, 2024, 10:43:15 pm »
I have too an aiop resistor box, but i use it  ;D
I've rebuilt them using cyanacrilate and sodium bicarbonate. For a 60v device i think that i not have insulation problems.
The result is not perfect, but good enough.
2061161-0
 

Offline tatel

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Re: AOIP PJ6301 schematic
« Reply #27 on: March 09, 2024, 10:50:33 pm »
Here it is... I'm going to machine the new parts from teflon

 

Offline tatel

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Re: AOIP PJ6301 schematic
« Reply #28 on: March 09, 2024, 10:56:26 pm »
Yours look much more modern than mine. Plastic isolation looks quite a lot thinner. It surprised me you was able to get the cap out. Where they already broken? Not going to touch caps on mine, just replace the isolation.
 

Offline masterx81Topic starter

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Re: AOIP PJ6301 schematic
« Reply #29 on: March 09, 2024, 11:02:24 pm »
I'm looking at my decade box, and not have the safety shroudings like the meter. You can replace them easily. The threads are m4, cam be found also qute cheap on aliexpress, or quality one form hirshmann or staubli
 

Offline masterx81Topic starter

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Re: AOIP PJ6301 schematic
« Reply #30 on: March 10, 2024, 12:18:36 pm »
I've removed the transformer, and the feedback is given by a second primary, it's a type of feedback that i not see very often, most of the times i see a feedback from the secondary via an optocoupler.
According to the de5000, the resistance/inductance of those 2 windings are :
From gnd to first tap: 285mohm / 154uH
From first tap to last tap: 265mohm/ 142,5uH
From gnd to last tap: 0.536mohm/ 588uH

Why both windings in series have an inductance that ins't the sum of both single inductances?
In general, not seem too bad

I've also found that the 2 6.8ohm resistors in series are out of spec, both at 7.4ohm. Not change much, this are here only to allow a soft discharge of the capacitor after them.
I think that the power section is good...
I've found a -15v voltage source on the board (i've still not found what generate it, i not see inductances), that is used to generate the -10v output, so the 66v are enough the 60v positive part output.
I think that is better, as the other components can be replaced.
I'm unsure about few components that were replaced by who have tried to repair it before me.
One is the mosfet, then the 2 diodes in photo:
2062502-0
I not know if were replaced with equivalent components.
I not know the mosfet what is used for, but i suspect for generating the output voltage (but if is generated with pwm, i would suspect that there is the need at least of a filter capacitor after the fet, but i not find any).
Now, i think that is time to use the scope for the next part of the fault finding....

Edit

Whops, the other secondaries that generate +15,-15 and +5 have gnd in common with the 35+35 taps, so the -15 is the same used for the opamps.
« Last Edit: March 10, 2024, 12:37:35 pm by masterx81 »
 

Offline masterx81Topic starter

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Re: AOIP PJ6301 schematic
« Reply #31 on: March 26, 2024, 09:41:12 pm »
After have replaced the two 6.8ohm resistors, the 6v and 60v ranges works very well. Allowed me to do the calibration, and are really accurate from -1/-10v to +6/+60v.
Now remain the problem on the 0.6v range, at 0v output i get near 0.820mv, and at 500mv i get 500.814mv, but during the calibration it give an out of range adjustment error.
And on the current output i still have an unwanted -2.368ma offset, that can't be adjusted...
Let's find the next problem....
« Last Edit: March 26, 2024, 10:36:47 pm by masterx81 »
 
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