Relay Question

Thread Starter

libra

Joined Jul 27, 2012
62
Hi,

I have buy the relay for the purpose to switch the LED ON when their is not electricity and LED OFF when electricity is present. so i connect the relay with the transformer 9VAC the relay is produce the noise sound then i turn off the AC.

At relay it was written that it work on 250VAC.

I also connect the relay with 9V battery but no sound is produced by the relay.


Here is the link from which you can see the relay which i Buy http://www.ebay.com/itm/100pcs-5V-DC-SONGLE-Power-Relay-SRD-5VDC-SL-C-PCB-Type-/250778760511?pt=LH_DefaultDomain_0&hash=item3a6394353f
 

edwardholmes91

Joined Feb 25, 2013
210
The reason the relay is making a buzzing sound is because you are using AC. There is nothing wrong with that... although you will hear a sound as the relay de-energises momentarily 50/60 times a second. It's called relay chatter... there is a circuit to minimise it but I don't know it sorry.
 

tracecom

Joined Apr 16, 2010
3,944
The relay coil you linked to is designed for 5 VDC to operate. If you use 9 VDC, you may burn out the coil.

It is the contacts which are rated for 250 VAC, not the coil.
 

edwardholmes91

Joined Feb 25, 2013
210
The relay coil you linked to is designed for 5 VDC to operate. If you use 9 VDC, you may burn out the coil.

It is the contacts which are rated for 250 VAC, not the coil.
Sorry, my mistake, I didn't even think to look at the link :rolleyes: If it states in the specification that you can operate the coil on either AC or DC... then that might be why you are getting the chatter effect.
 

Thread Starter

libra

Joined Jul 27, 2012
62
I gave the coil 9VAC then it produced the buzzing sound. Not on 9VDC.

Did i contact it 220VAC/50HZ? Because i buy it for that purpose. The purpose is that when the AC is not available the LED will turn ON and OFF when AC power is available and battery start charging.
 

tracecom

Joined Apr 16, 2010
3,944
No, if you connect the coil of a 5 VDC relay to 220 VAC, you will immediately destroy the coil, and the relay will be ruined. It may catch on fire.
 

mcgyvr

Joined Oct 15, 2009
5,394
You need a relay with a "Coil Voltage" rating of 220VAC. You connect your "electricity" to the "coil" and your LED is switched with the relays "contacts"

And please be safe..frankly this is really something you shouldn't be doing as you are exposing yourself to shock hazards/death playing with your AC "electricity".. AC is NOT for beginners.
 

tubeguy

Joined Nov 3, 2012
1,157
Hi,

I have buy the relay for the purpose to switch the LED ON when their is not electricity and LED OFF when electricity is present. so i connect the relay with the transformer 9VAC the relay is produce the noise sound then i turn off the AC.

At relay it was written that it work on 250VAC.

I also connect the relay with 9V battery but no sound is produced by the relay.


Here is the link from which you can see the relay which i Buy http://www.ebay.com/itm/100pcs-5V-D...511?pt=LH_DefaultDomain_0&hash=item3a6394353f
Where are you getting 9 volts AC when the power is off ?
 

Thread Starter

libra

Joined Jul 27, 2012
62
I am getting 9 volt AC from transformer. I will not operate the relay on 220 volt ac. i use transformer of 6 volt ac, then connect it with bridge and then relay. In that i thing i put in safe way or not?
 

crutschow

Joined Mar 14, 2008
34,469
Sorry, my mistake, I didn't even think to look at the link :rolleyes: If it states in the specification that you can operate the coil on either AC or DC... then that might be why you are getting the chatter effect.
MY reading of the spec says the coil is rated for 3-48V DC (although I'd be surprised if it will actually that high a voltage) . The contacts are rated for AC but not the coil.

Operating the coil from the transformer is safe but you will need to rectify (and perhaps filter) the voltage.
 

#12

Joined Nov 30, 2010
18,224
I'm seeing 5V, DC only, 75ma to 90 ma by reading the label on the relay. As far as the Chingrish description, all bets are off. Maybe this drawing will give ideas.
 

Attachments

Thread Starter

libra

Joined Jul 27, 2012
62
I'm seeing 5V, DC only, 75ma to 90 ma by reading the label on the relay. As far as the Chingrish description, all bets are off. Maybe this drawing will give ideas.
Thank you for the drawing. It will help me alot. I also making this drawing but i do not put the zener-diode in it.
 

Thread Starter

libra

Joined Jul 27, 2012
62
MY reading of the spec says the coil is rated for 3-48V DC (although I'd be surprised if it will actually that high a voltage) . The contacts are rated for AC but not the coil.

Operating the coil from the transformer is safe but you will need to rectify (and perhaps filter) the voltage.
Yes after rectify and filter then to relay. As suggested by #12.
 
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