Date:   7/26/2009 12:28:40 AM ( 15 y ago)
Hits:   71,842
URL:   https://www.curezone.org/forums/fm.asp?i=1462444

"i just realised that the big capacitor , the 1 that is supposed to be 200 uf, well the 1 i have put in is actually 220 uf, that's 20uf difference, could this be the problem do you think?"

That will effect timing of the 555 timer chip, by how much I do not know. But the frequency go up with lower uF rating and gets lower with higher uF CAP because the larger the cap the longer it will take to charge. You also need 4 1.5V dc batteries to run the 555 timer chip otherwise there will be no signal send to the relay switch which reverses the polarity.

This is much more complicated build then it needs to be. The newer version is much easier to build.

Your resistors are correct.

I would now investigate if you are making connections where they are not suppose to be as the older diagram does not identify well where actual connections are when circuit runs intersect. This is where you could have trouble as your output is zero volts. It sounds you are shorting out your circuit.

LED constant on could be your testing switch - is it true momentary on? It should only work when you hold it down and release when you let go at that point LED should go off again.
Second reason could be short to active circuit keeping it on all the time.
Third possibility is miss wired relay is not switching - can you hear it click? Again make sure you are not shorting the circuit with unwanted connections. Trace back trough your circuit where in diagram it appears there is connection, but it actually should not be a connection, just two circuit runs intersecting with out connecting. Again it is hard to tell in the diagram.

I have made real component circuit diagram for my build for those who wish to replicate it. Here is the excel file:
//www.curezone.org/upload/PDF/single_9Vbeck_device1.xls


Gill




 

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