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Old 26th November 2006, 11:18 AM   #721
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Hi

It sounds like you might have a short. Use your dmm to see if there is a short from the output of the 7812 to GND.

Inspect the board very carefully for solder bridges.

Cheers!
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Old 26th November 2006, 07:17 PM   #722
D1GGY is offline D1GGY  New Zealand
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I have measured the voltage output from the Trafo (no load) and i get 15V. This is not correct is it, it should be 30V

I am using the standard amveco transformer and am trying to get my head round the issue of primary and secondary configurations with regard to 230V operation. I have wired the primary in series configuration as highlighted in on the Amveco website and in the earlier post, but i am convinced that the secondary configuration needs to changed also in order to get 30V out,

Is it coincidence that i am getting 15v output due to wiring configuration or did I fry one windings (by turning the trafo into a small heater )before I realised that i needed to modify the primary to work work with 230V and not 110?

i will also check for shorts when i get back from work.

mark
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Old 26th November 2006, 07:21 PM   #723
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Quote:
Originally posted by D1GGY
I have measured the voltage output from the Trafo (no load) and i get 15V. This is not correct is it, it should be 30V

I am using the standard amveco transformer and am trying to get my head round the issue of primary and secondary configurations with regard to 230V operation. I have wired the primary in series configuration as highlighted in on the Amveco website and in the earlier post, but i am convinced that the secondary configuration needs to changed also in order to get 30V out,

Is it coincidence that i am getting 15v output due to wiring configuration or did I fry one windings (by turning the trafo into a small heater )before I realised that i needed to modify the primary to work work with 230V and not 110?

i will also check for shorts when i get back from work.

mark
Hi Mark,

Make sure your secondaries are wired in series, and that the point where you join the secondaries (the center tap) is connected to the center "GND" pin on the power header/connector.

Cheers!
Russ
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Old 26th November 2006, 07:36 PM   #724
D1GGY is offline D1GGY  New Zealand
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Default brown & red connected together - brain failure the likely cause!!

You have got me thinking........

i may have measured quite correctly 15V between the centre pin and each of the phase (hot) pins and not engaged brain before opening mouth.....(for some reason expecting 30V)

I will check tonight and go from there before i disapear in ever decreasing circles

m
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Old 27th November 2006, 12:26 AM   #725
D1GGY is offline D1GGY  New Zealand
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OK, I have noticed one thing, One of my caps (round one next to C20) is the otjher way round to the example on the twistedpear website, mine is soldered as per the PCB detail, has ths been changed in the design at all?

I have also included the image below, any thing obviously wrong looking at this?
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Old 27th November 2006, 12:28 AM   #726
D1GGY is offline D1GGY  New Zealand
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And the soldering...
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Old 27th November 2006, 12:31 AM   #727
D1GGY is offline D1GGY  New Zealand
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Sorry spotted it,

Half of the Bridge rectifier diodes are round the wrong way......
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Old 27th November 2006, 12:33 AM   #728
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Yes, the bottom 4 diodes should be installed the other direction.
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Old 27th November 2006, 07:31 PM   #729
D1GGY is offline D1GGY  New Zealand
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OK I do not want to trash this thread by going through how to repair a kook after some muppet not installing the components correctly trashed his, but how might i go about fixing my cooked kook....

The diodes are now installed correctly, I measured the output voltage on the voltage regulators and two read 19V +- and one 12V one 5V so i assume two are trashed, these i will replace but what else is likely to have become fit for the bin?

Am i better getting another kit at this point and learning to read?

Mark
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Old 27th November 2006, 07:36 PM   #730
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Quote:
Originally posted by D1GGY
OK I do not want to trash this thread by going through how to repair a kook after some muppet not installing the components correctly trashed his, but how might i go about fixing my cooked kook....

The diodes are now installed correctly, I measured the output voltage on the voltage regulators and two read 19V +- and one 12V one 5V so i assume two are trashed, these i will replace but what else is likely to have become fit for the bin?

Am i better getting another kit at this point and learning to read?

Mark

I well I think the worst case would probably be that you would need to replace all the other ICs. That would be the PGA, two opamps, and the PIC. You would also want to test each of the caps to make sure that they have not become a short.

Sorry for your bad luck, I have made many similar mistakes myself.

Cheers!
Russ
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