Compressor timer

Thread Starter

soda

Joined Dec 7, 2008
177
Is the Cap discharging properly in that manner. ?

If it cannot discharge then timer won't work in the successive cycles. I think this is why u are getting one time buzzes. It is discharging over time.
Rifaa, when i press the start button, the relay flip from normal close to normal open on the one side of the relay. When this happen, the supply to the capacitor was cut off because if you look closely to the schematic,you'll notice that the cap was connected to the normal close contacts

I bet you never read my reply's, because the questions you asked let me think it's like that. I've already said that the circuit is working now, mate
 
Last edited:

Thread Starter

soda

Joined Dec 7, 2008
177
Care to share some pictures...?
I can take some pic's if you like, but just remember, it a dirty mess around that etching tank

I just take a plastic bucket with a lid and then add sparge pipes to the bottom. An single pipe from the compressor is then feeding the air to the sparge pipes which causing the bubbles in the tank.The pcb hang on top of this on another pvc bracket. It's got a pvc adjustable screw to set the different sizes of the boards.

The best part is my UV scanner, witch i use for the exposure of the board. Do you want me to add those pic's as well?
 

nerdegutta

Joined Dec 15, 2009
2,676
Why not create an album, and put all the picture there? Then it won't get lost when this thread eventually dies...

A picture says a thousand words, you know.
 

praondevou

Joined Jul 9, 2011
2,942
Rifaa, when i press the start button, the relay flip from normal close to normal open on the one side of the relay. When this happen, the supply to the capacitor was cut off because if you look closely to the schematic,you'll notice that the cap was connected to the normal close contacts

I bet you never read my reply's, because the questions you asked let me think it's like that. I've already said that the circuit is working now, mate
I have to agree with Riffa. I'm glad you have it working, but the right side of the coupling capacitor is "floating", i.e. it's not at a defined voltage potential when the compressor is on.

If it's working then try to use it as it is. If you run into further problems, I described how to do it.

Good luck
 

Thread Starter

soda

Joined Dec 7, 2008
177
I have to agree with Riffa. I'm glad you have it working, but the right side of the coupling capacitor is "floating", i.e. it's not at a defined voltage potential when the compressor is on.

If it's working then try to use it as it is. If you run into further problems, I described how to do it.

Good luck
Ok thanks for the advice, but can you please explain why it's so important for the cap to be always connected to the power line. The thing is I've tested it on a breadboard and the cap constantly give a short pulse to Q1 each time i removed and reconnect the power and when i leave it connected, there was no pulse at all.

I'll be away this weekend but will be back on Tuesday.
(Sorry Rifaa if i was ugly with you)
 

praondevou

Joined Jul 9, 2011
2,942
Ok thanks for the advice, but can you please explain why it's so important for the cap to be always connected to the power line. The thing is I've tested it on a breadboard and the cap constantly give a short pulse to Q1 each time i removed and reconnect the power and when i leave it connected, there was no pulse at all.
The cap discharges by itself after a certain time. The way you connected it (according to your last picture) the correct way would be to add a resistor (100k for example) from the NC contact to Gnd, at the contact the cap is connected to. It will then be discharged when the relay is activated, i.e. the NC contact is open.

Leaving it open is just not the right way to do it, even if it works.
 

Thread Starter

soda

Joined Dec 7, 2008
177
The cap discharges by itself after a certain time. The way you connected it (according to your last picture) the correct way would be to add a resistor (100k for example) from the NC contact to Gnd, at the contact the cap is connected to. It will then be discharged when the relay is activated, i.e. the NC contact is open.

Leaving it open is just not the right way to do it, even if it works.
Thanks praondevou. I see what you mean. I'm going to change my circuit the way you explained above and make a note for future use.

Thanks again for all your help.
 
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