Relay Problem

Discussion in 'The Projects Forum' started by kieron151, Jul 11, 2013.

1. kieron151 Thread Starter New Member

Sep 5, 2010
8
0
I'm using a monostable delay timer to operate a 12v electro holding magnet, As soon as I connect the the power, the relay stops working altogether, Can anyone help me find a solution.

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2. rsfoto Member

May 14, 2013
134
1
Hi,

Perhaps I can help.

When you have no power connected to the circuit the relay works and as soon as you connect power to the circuit it stops working ?

The relay on your circuit is a SPDT Single Pole Double Throw relay.

NC means Normally Closed and if you connect something there between Common and NC it is always connected unless you send a pulse and it disconnects.

If you connect to NO = Normally Open and Common then that line is open and will close when the circuit is activated.

So you have there the possibility to either switch ON or switch OFF with a pulse. SO you need to decide if you want to actuvate something it must be connected to NO and common.

I hope that helps.

So far is what I understand does your circuit do.

3. ScottWang Moderator

Aug 23, 2012
6,421
994
What's the function you want, relay working after a delay time or waiting for a delay time to work?

If you want the relay working after a delay time, then after you power on, did you push the S1(Trig)?

4. kieron151 Thread Starter New Member

Sep 5, 2010
8
0
The magnet is a two pole connection, I have a connection to earth X1 and the other to NO, I want the magnet to be on when S1 is pressed and off when S2 is pressed, I connected a 12v buzzer the same way and it worked fine.

5. #12 Expert

Nov 30, 2010
18,093
9,679
Maybe the magnet requires so much current that it is dragging down the power supply.

6. ScottWang Moderator

Aug 23, 2012
6,421
994
What's your 12V power and how much current it can offer?
How much current of Buz?
How much current of magnet?
After the power is on, when you press S1, you can measure the voltage of Pin 3 of NE555.

7. tubeguy Well-Known Member

Nov 3, 2012
1,157
198
If you have an ohm meter, post the magnets resistance.
Or, measure the power supply voltage first with the magnet directly connected and then disconnected.

8. kieron151 Thread Starter New Member

Sep 5, 2010
8
0
Just Like to thank all of you that's helped, The problem wasn't with the relay or the amount of current to the magnet, It was a simple and stupid error by me, The magnet is an energise to release, so all I had to do is swap wire from NO to NC, so off is on, on is off. What an idiot!!!

9. wayneh Expert

Sep 9, 2010
15,000
5,453
Hardly. There's a reason it's called Murphy's LAW.