On going power supply question??

[MrPontiac]

Its got me scratching my head,. i can be going along copy cading parts then out of the blue i loose my voltage and my amps go way up, I know i thought i had a bad connection, i check all my wires, i have a jumper between my anodes witch now are new, there perfect visualy, my black wire connected to the copper pipe is perfect, im using a copper wire connected to a brass hook, its ok,, My power supply has a button next to the voltage scale, if you hold it in or tape it in the voltage reads good then?? Im stumped here ive tryed everything, could it be the red jumper between anodes, its just a thin wire electrical jumper with aliagator clips?? I can plate a few more parts and then its works again?? Looking for suggestions, anybody??

[chromo]

"My power supply has a button next to the voltage scale, if you hold it in or tape it in the voltage reads good then?"

Maybe dumb question, but have you tested the power supply itself? Test when NOT putting out the volts on the scale. Could be under a load something is getting hot or such and the power supply is messing up, not your setup. Test the wires for the power supply close to the supply as you can. They should show your volts rather your parts are getting the volts or not if the supply is putting out the volts.

I don't have any idea what that black button is for, but it must do something to the power supply since it does not really do anything for the parts right. So if pressing the button puts out the right volts but not pressing it you lose the volts, again I think it might be in the supply.

I would run it as normall till the scale drops the volts. Just connect a digital meter to the power suppies wires. Watch the volts on the meter and the scale, see if they match and if they stay the same. Does the scale drop low but the meter still read high? Do both drop?
If the meter shows low volts also then disconnect a wire from your tank and see if the volts jump right back up again.

Also you could test the power supply under load without your tanks. Figure out your normal Volts X amps = watts. Once you know the watts your normally running connect a few car tail light bulbs and light them up awhile with the power supply. See if after about the same amount of time the volts drop on your scale as when tanking. If the volts drop of course you then know it's the supply and not your setup.

[seanc]

Voltage going to 0, and current going to max., indicates a short circuit. Perhaps your parts are touching the anodes?

Sean

[fmahone]

What type of power supply are you using? Brand, model, etc.

The full scale amps and no volts indicates an excessive load with the power supply going in to current limiting (that's why zero volts, high current).

The black button may be an output circuit breaker or a way to set the current limit. No load you push the button and set the maximum current. This, of course, is if it has such an adjustment.

I do not know of any power supply failure that could cause this and not open the main fuse or circuit breaker. Shorts on the output reflect back to the input.

There could be an overvoltage circuit that has failed and is tripping at a lower voltage than originally set, but usually they completely shut the power supply off or open the main fuse.

[MrPontiac]

seanc, i think you may of figured it out, yes i had a long piece in the bucket, it may be hitting the anodes, may i ask, if the copper pipe is corroded very badly would that cause it I clean the pipe every time i use my rectifier, but after about 15 parts its corroded pretty badly.

[seanc]

Originally Posted by MrPontiac

.. if the copper pipe is corroded very badly would that cause it

No, that would have the opposite effect.

Voltage would go high, and current would drop low. A complete loss of connection would be an effective open circuit, and current would be zero.

I clean the pipe every time i use my rectifier, but after about 15 parts its corroded pretty badly.

I run into the same issue, and clean the pipe as soon as I see visible corrosion.

Sean

[MrPontiac]

Seanc, im no electrical wizzard but i thought that also may be the problem, i polished my copper pipe and even made sure the copper wires where clean, seems you found the problem, im ok, now, i think, just after about 20 parts that pipe looks nasty!! I guess my next question is, Is there anything i can do to keep the green corozon down??

[seanc]

Originally Posted by MrPontiac

I guess my next question is, Is there anything i can do to keep the green corozon down??

You could zinc plate it. It will last longer, but will still eventually oxidize/corrode. You might also wipe it with a thin layer of dielectric grease, but then you run a risk of getting grease on your fingers during handling, & transferring it to the parts.

I prefer to leave mine bare copper for maximum conductivity (copper is a better conductor than zinc), and put up with cleaning it every so often.

Sean

[kxkraze]

You can get rid of that green corrosion in a second or two by dipping your copper pipe in a bath of #4 pickle. I have a special bucket just for this. I also clean the pipe at the end of a plating session so that it can dry. Don't want that pickle in your plate solution. If you have an air compressor, it helps to blow out the inside of the pipe after you pickle it.

Pickle it
Rinse it
Compressed air (if available)
Allow it to dry.

[JewellerTed]

Originally Posted by kxkraze

...
Compressed air (if available)

Make sure that your compressor's motor is separated from the compressor itself, or else your compressed air will carry a microscopic oil-film from the motor-oil. You can usually smell the oil if you stick your nose into the compressed air. If it smells oil, better not use it in galvanic environments (and not in jewellery casting)

Ted