Manson NP-9613

[budm]

Re: Manson NP-9613

It looks like the easy test for the relays is to force them on then measure the Voltage drops on the relay contacts.
https://www.badcaps.net/forum/attach...9&d=1580238857

[R_J]

Re: Manson NP-9613

A relay not moving (stuck, open coil or bad control transistor) cannot not give zero output, as I see it. There is always a transformer tap feeding the bridge, one is alway switched in - unless a contact has failed open-circuit. So it's likely the relay has failed, or another problem altogether with the pass transistors/op-amp. OP is jumping around too much to really troubleshoot this.

Thats what I said, Likely the relay burnt one of the contacts so when it does switch, It contacts nothing so the voltage drops, when the relay switches back to the good contact the voltage comes up again. And I agree, about the jumping around, but when I said something I got shit for it.

[redwire]

Re: Manson NP-9613

A relay not moving (stuck, open coil or bad control transistor) cannot not give zero output, as I see it. There is always a transformer tap feeding the bridge, one is alway switched in - unless a contact has failed open-circuit. So it's likely the relay has failed, or another problem altogether with the pass transistors/op-amp. OP is jumping around too much to really troubleshoot this.

[R_J]

Re: Manson NP-9613

No relay/coil control combination will give zero output (nothing across C2).

The only way for the voltage across C2 to drop to 0 would be if one of the relay contacts was bad or the winding it was switching to was open. The OP checked the transformer, so it is ok, so it could be a burnt contact in one of the relays. Thats why checking the voltage across C2 when the relay clicked was important.

[redwire]

Re: Manson NP-9613

No relay/coil control combination will give zero output (nothing across C2).
I'm not sure why OP is not listening or taking those measurements.

It might be a different problem. OP says something went wrong with the pass transistors, so possibly that damaged the control circuit.

I have seen Manson power supplies where you dial up the output voltage and suddenly over a few seconds output just falls and then it sits there at almost nothing. It's like something heated up and then it collapsed.

The pass transistors 2N3055 and TIP31C are normally on full blast (R2), and the op-amp only turns them off for CV or CC mode.
If a 2N3055 or TIP31C shorted, the CC LED can explode and the op-amp IC gets damaged. Or the CV section gets cooked.
This NP-9613 model is missing protection diodes and resistors, so it damages the 4558 op-amp IC very easily. Never charge batteries with it.

[R_J]

Re: Manson NP-9613

I changed Q4, could it be Q5 is not working as well ? thanks

It could be, Q5 drives Q4, Was Q4 shorted? Also check R23. Can you tell which relay RLY1 or RLY2 is operating when you turn up the voltage control?
one should operate, then as the voltage increases the other will operate.

It is a bit of a strange circuit but I marked the COMMON in GREEN for the relay circuit. Q5 and Q8 get turned on by the voltage on the negative BLACK Ground line, so the VOLTAGE DIFFERENCE between common and ground is what tells the relays to operate. The voltage the relays operate at is set by VR7,VR8 & VR9 (dont adjust these).

The line I marked in light blue is just to supply the dc for the relays via R21 and R22.
The darker blue is the +12 volts for the relay drive circuit. and for the positive side of U1.
The yellow line is the negative 5.6v supply for U1
The orange line is just raw DC (25v?) for the fan
The pink is the +15v for the thermal and fan drive circuit.

I hope this makes the schematic a bit easier to follow

The way this power supply works is the DC across C2 will be lower for a DC output of 0~x volts.
as you continue to turn up the voltage control RLY2 changes switches to the other tranformer terminal increasing the voltage to C2to supply the DC output from Xvolts~Yvolts
As you continue to turn up the voltage control to get maximum voltage Y~30volts RLY1 switches to the other transformer teminal providing the maximum voltage across C2 (40v?)
As you turn the voltage control down, RLY1 switches back, the as you continue turning the control down, RLY1 switches back.

[bianchi77]

Re: Manson NP-9613

There are 2 relays that do the voltage switching, correct? In post #11 you replaced both 2n3904 transistors, which ones were they? Q4,Q5,Q7 or Q8. It could be that one relay is switching but not the other one.
I suspect as you increase the voltage from 0, after it reaches a certain point (voltage), one of the relays switches to increase the voltage across C2, as you continue to increase the voltage the other relay switches and increases the voltage across C2 to maximum (around 40v) It could be that the second relay is not switching to give you the extra input voltage to stabalize the output

I am trying to help, but I don't know which parts were damaged other that ZD1

I changed Q4, could it be Q5 is not working as well ? thanks

[bianchi77]

Re: Manson NP-9613

So now you say it works above 19 volts, but the voltage from 20~30v is not stable?
The reason I had asked to measure the AC voltage across the input to the bridge rectifier was to confirm the operation of the transformer, The relays AND the circuit that drives the relays.
If that is difficult to check this part of the circuit (hard to get at), Then check the voltage across C2 (4700µf) This voltage is NOT REGULATED so it will be at least 46 volts DC. (based on the 33vac you measured)
If this voltage is there, THEN you can start checking the REGULATED circuit Q1, Q3 etc. but you must have a stable and at least 31volts on Q1 collector. If you don't have this voltage then the voltage from Q1 emitter will not be stable.

Let me check the voltage across C2 and see...

[R_J]

Re: Manson NP-9613

There are 2 relays that do the voltage switching, correct? In post #11 you replaced both 2n3904 transistors, which ones were they? Q4,Q5,Q7 or Q8. It could be that one relay is switching but not the other one.
I suspect as you increase the voltage from 0, after it reaches a certain point (voltage), one of the relays switches to increase the voltage across C2, as you continue to increase the voltage the other relay switches and increases the voltage across C2 to maximum (around 40v) It could be that the second relay is not switching to give you the extra input voltage to stabalize the output

I am trying to help, but I don't know which parts were damaged other that ZD1

[R_J]

Re: Manson NP-9613

So now you say it works above 19 volts, but the voltage from 20~30v is not stable?
The reason I had asked to measure the AC voltage across the input to the bridge rectifier was to confirm the operation of the transformer, The relays AND the circuit that drives the relays.
If that is difficult to check this part of the circuit (hard to get at), Then check the voltage across C2 (4700µf) This voltage is NOT REGULATED so it will be at least 46 volts DC. (based on the 33vac you measured)
If this voltage is there, THEN you can start checking the REGULATED circuit Q1, Q3 etc. but you must have a stable and at least 31volts on Q1 collector. If you don't have this voltage then the voltage from Q1 emitter will not be stable.

[bianchi77]

Re: Manson NP-9613

AVO = Ampere Volt Ohm....it's the meter, I used to call it AVO
Yes it does measures AC voltage out of the transformer..

I tested this area :

[bianchi77]

Re: Manson NP-9613

If you won't do the test like I asked then what is the point? The circuit is so simple and so easy to test but you won't do it.
If you car does'nt start do you change the tires?

The transistors are working, The circuit works from 0 to 19 volts correct? or is that NOT correct?
You keep saying "I'm not sure if the relays are good or not" I gave you a simple way to test them but you refuse.

What is the AVO? Does it measure the AC voltage out of the transformer?

AVO = Ampere Volt Ohm....it's the meter, I used to call it AVO
Yes it does measures AC voltage out of the transformer..

[bianchi77]

Re: Manson NP-9613

If you won't do the test like I asked then what is the point? The circuit is so simple and so easy to test but you won't do it.
If you car does'nt start do you change the tires?

The transistors are working, The circuit works from 0 to 19 volts correct? or is that NOT correct?
You keep saying "I'm not sure if the relays are good or not" I gave you a simple way to test them but you refuse.

Which test hadn't I done ? yes, it's working from 0 to 19V..
I tested to maximum, it can show until 30V on the output but not stable and going down...

Thanks for helping, take it easy R_J....

[R_J]

Re: Manson NP-9613

If you won't do the test like I asked then what is the point? The circuit is so simple and so easy to test but you won't do it.
If you car does'nt start do you change the tires?

The transistors are working, The circuit works from 0 to 19 volts correct? or is that NOT correct?
You keep saying "I'm not sure if the relays are good or not" I gave you a simple way to test them but you refuse.

What is the AVO? Does it measure the AC voltage out of the transformer?

[bianchi77]

Re: Manson NP-9613

How do you measure 3 different voltages on 2 points? Or is that voltage measured across C1 as you turn up the voltage control? You need to explain what your doing.

One thing I wonder is when you advance the voltage control between 0 and 19 volts, during that variation, do you ever here one of the relays click?


There is nothing wrong with the 4700µf. even if its value droped to 1000µf, the voltage would not drop because you are not drawing any real current from the power supply at the moment.

There is a connector from the transformer, I opened it, I want to check the condition of the transformer,
4 pins on it, I put one as reference (0) and the other for checking the secondary voltage output, from the result, the transformer is ok .

I checked it with AC voltage on my AVO.

I'm not sure if the relay is good or not, or may be one of the 3 transistors is not good 2x 2N3055 and 1 x TIP 31, I have replaced one of 2N3055 since I checked the hfe of it, it's low. but it doesn't help yet....

Could it be TIP 31 ?

Thanks

[R_J]

Re: Manson NP-9613

I got
13V 23V and 33V on the transformer voltage...

How do you measure 3 different voltages on 2 points? Or is that voltage measured across C1 as you turn up the voltage control? You need to explain what your doing.

One thing I wonder is when you advance the voltage control between 0 and 19 volts, during that variation, do you ever here one of the relays click?


There is nothing wrong with the 4700µf. even if its value droped to 1000µf, the voltage would not drop because you are not drawing any real current from the power supply at the moment.

[bianchi77]

Re: Manson NP-9613

When you say "no more voltage increasing" That AC voltage will be constant untill the relay clicks? OR did the voltage drop to 0? It can't just stay the same if the relay clicks, if it does then the relays are not switching at all.

What is the AC voltage on those points on the transformer? I will guess what they are and you can check them. (you don't need to adjust the dc output pot)

Provide pictures of the transformer and the relays and how they are connected

is it possible that 4700uF caps going bad ? making the output drop ?

[bianchi77]

Re: Manson NP-9613

When you say "no more voltage increasing" That AC voltage will be constant untill the relay clicks? OR did the voltage drop to 0? It can't just stay the same if the relay clicks, if it does then the relays are not switching at all.

What is the AC voltage on those points on the transformer? I will guess what they are and you can check them. (you don't need to adjust the dc output pot)

Provide pictures of the transformer and the relays and how they are connected

I got
13V 23V and 33V on the transformer voltage...

[R_J]

Re: Manson NP-9613

When you say "no more voltage increasing" That AC voltage will be constant untill the relay clicks? OR did the voltage drop to 0? It can't just stay the same if the relay clicks, if it does then the relays are not switching at all.

What is the AC voltage on those points on the transformer? I will guess what they are and you can check them. (you don't need to adjust the dc output pot)

Provide pictures of the transformer and the relays and how they are connected

[bianchi77]

Re: Manson NP-9613

I told you how to check the voltage going to the relays (this also checks the relays) here is a picture of what to do. This should be easier then removing them and testing them.
I will only guess there are two relays and I they may switch at different times based on the output voltage.
If the relay contacts are bad you should measure the AC likeI pointed out when the DC output is low (less than 19v) then as you increase the control to increase the voltage and the relay clicks, If the AC voltage drops, one of the relays contacts are bad. (ore the transformer winding is open) or bad connection from transformer to relay somwhere.

It could have been the transformer, since I rotated until 20V and no more voltage increasing on the point you gave me, and the pot was maximum...

if the transformer winding is opened....difficult..