Paradise Builders

[RCruz]

Originally Posted by brozatus

@Rcruz,

yes, as I said, I measure AC volts after the rectifiers.

see the schematic:

I have about 81 ac between plus vdc and ground, 163 v ac between plus vdc and minus vdc.

@studeb,

please look at the schematic, it is exactly as I explained it.

Thanks a lot,
Christoph

That is very strange.... can you measure again with a different DMM ?

Maybe your DMM is plying tricks with you

Please check the rectifiers.

A picture of your setup would help enourmously

[brozatus]

Hello Rcruz,

I have no second dmm

First time I try to get some pictures in here
Topside
[IMG][/IMG]

Underside, next time I will do better
[IMG][/IMG]

DC on output
[IMG][/IMG]

DC across the resistor
[IMG][/IMG]

AC across the resistor
[IMG][/IMG]

AC on output
[IMG][/IMG]

Did some mistakes putting pics in, they are in my photo gallery.

Regards,
Christoph

[RCruz]

What are those yellow / black wires coming from the sides of the board ?

What is the AC voltage in the input ? (TX secondaries).

Please build a simple diode bridge, connect it to the TX and make the same measurements... (test the diodes continuity befor build just to be sure they are ok)

If the diodes are ok, and you still measure AC after the bridge... something is wrong with the DMM

[brozatus]

Hello Rcruz,

the yellow and blacks are the cables of the chokes.

AC input voltage is 27 v

Tomorrow i will try to build the diode bridge and do the measurements.

Thanks a lot for helping,
Christoph

[RCruz]

If AC input is 27Vac, there is no way you could get 80Vac after the rectifiers.... Something must be wrong with the DMM.

Try loading the output of the board with a 1000ohm and measure the voltage across... then lift one leg of the resistor and measure the current throu it with the dmm.

[mkoerner]

Are you 100% shure, that you got the connection to the trafo right? Are the windings really black/blue each and not black/black , blue/blue (which imho is more common).

Mike

[mkoerner]

Originally Posted by RCruz

If the diodes are ok, and you still measure AC after the bridge... something is wrong with the DMM

If you measure behind a diode bridge there will always be some AC, but it has to be very low compared to the DC, (it's the ripple...). If it's still higher than DC THEN there is something wrong with the Voltmeter.

Mike

[Bksabath]

Originally Posted by brozatus

Hello Rcruz,

the yellow and blacks are the cables of the chokes.

AC input voltage is 27 v

Tomorrow i will try to build the diode bridge and do the measurements.

Thanks a lot for helping,
Christoph

Just a couple of comments while You fault find on boards nothing major but Paradise is realy good and worth the effort

Can you draw/post SCH of your circuit.
I wuld reccomend you use 2 rectifiers board to suply Pardise
I posted a picture of my BETA PSU the top board uses the same telema common mode cokes
Can you etch your own boards as if you need I can post the PCB lay out as I am using it
Could you get better diodes?
I have posted picture of beta PSU

The AC there as shown by your multymeter is definetley wrong

[sq225917]

Sabbath, what transformers did you use?

[PMA]

Originally Posted by RCruz

If AC input is 27Vac, there is no way you could get 80Vac after the rectifiers.... Something must be wrong with the DMM.

Try loading the output of the board with a 1000ohm and measure the voltage across... then lift one leg of the resistor and measure the current throu it with the dmm.

There is ....

As you are saying, he has to load output of the power supply board. Plus Vdc vs. ground and Minus Vdc vs. ground with something like 1 kohm - 10 kohm. Without this load, the output capacitors with inductors in series may create resonant circuit and the DMM may either measure voltage on the overcharged capacitor or it is fooled by resonance. With output reasonably loaded, everything should be OK.