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Author Topic: Problem with circuit  (Read 6088 times)

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manley_V

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Problem with circuit
« on: March 01, 2008, 21:45:48 PM »
Ok. I am getting now a little bit nuts.

I have this circuit made. It is a simple circuit with some decade dividers and a clock (with 555 timer) that periodically it will have to switch 6 relays on and off. Each relay will control one small motor. Only one motor each time will function. Every relay output has a reverse current diode limit and is driven by a 2n222 power transistor. I also tried a darlington connection.

Now what happens is really strange. I test the circuit w/o load (i mean motors) and acts as it should be. It turns on and off the relays according to the limit switches and the timer and everything else is correct. When i connect the motors it goes pop. It works somehow but from time to time start go crazy. I really do not understand what is going on.

I checked for shortcircuits or broken motors or something but seems to work correct.

Please help me. Save me from going nuts!

kam

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Re: Problem with circuit
« Reply #1 on: March 01, 2008, 22:13:47 PM »
Well that is strange. Can you post a schematic for this?

Alex

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Re: Problem with circuit
« Reply #2 on: March 01, 2008, 22:47:18 PM »
And what kind of motors do u use?

Erkeli

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Re: Problem with circuit
« Reply #3 on: March 02, 2008, 01:28:14 AM »
is there any kind of galvanic connection between the components before the relays and the motors? Because if there is one, then it may be some kind of noise of the motor. even if they have common power supply.
If also you have the same power supply to the motor and to the circuit (which i do not expect that you have done such a mistake) then it would be normal to have brown out to the ttl as they have a narrow operating voltage range.  :-\

manley_V

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Re: Problem with circuit
« Reply #4 on: March 02, 2008, 02:28:02 AM »
ehmmmm...  :-X :-X :-X :-X

Just don't tell anyone ok?

It was a brown out because of the supply. I put a bigger psu and it works.

Let's just stay between us... :'( :'(

kam

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Re: Problem with circuit
« Reply #5 on: March 02, 2008, 02:35:57 AM »
shit happens  ;)