Another relay thread. Relay's not activating completely

[mcshaner2k]

I read through as many relay threads as I could, I can't figure this out.

My relays aren't completely engaging/making contact.

I'm running radio shack transformer 273-1365A @ 12v 450ma, 7812 12v voltage regulator, G5V-2 12v relays, and a prefab relay board. I'm getting 17v dc coming out of the board to regulator input and 12.3v dc of output from regulator to relays. The relays activate with a 9v battery and I get continuity between poles when switching, so I know the relays are working.



Link to prefab board

http://agbamplifiers.com/pcb/RELAY%20PS ... 0NOTES.pdf

[ayan]

I wonder if the relays you're using might be polarized. If that is not the case, have you checked the voltage at the output of the regulator when the relays are energized?

Gil

I read through as many relay threads as I could, I can't figure this out.

My relays aren't completely engaging/making contact.

I'm running radio shack transformer 273-1365A @ 12v 450ma, 7812 12v voltage regulator, G5V-2 12v relays, and a prefab relay board. I'm getting 17v dc coming out of the board to regulator input and 12.3v dc of output from regulator to relays. The relays activate with a 9v battery and I get continuity between poles when switching, so I know the relays are working.



Link to prefab board

http://agbamplifiers.com/pcb/RELAY%20PS ... 0NOTES.pdf

[hitchcaster]

450ma not enough for your relays maybe?

[mcshaner2k]

I wonder if the relays you're using might be polarized. If that is not the case, have you checked the voltage at the output of the regulator when the relays are energized?

Gil

I read through as many relay threads as I could, I can't figure this out.

My relays aren't completely engaging/making contact.

I'm running radio shack transformer 273-1365A @ 12v 450ma, 7812 12v voltage regulator, G5V-2 12v relays, and a prefab relay board. I'm getting 17v dc coming out of the board to regulator input and 12.3v dc of output from regulator to relays. The relays activate with a 9v battery and I get continuity


between poles when switching, so I know the relays are working.



Link to prefab board

http://agbamplifiers.com/pcb/RELAY%20PS ... 0NOTES.pdf

I noticed that I'm getting 12v on both the negative and positive terminals of the relay board when the relays aren't active. I thought this was weird, but the relay doesn't see a ground until the switch is active.
I'm not sure if I checked the voltage at the regulator while the relays are active. I'll check that out later. The relays are rated at 2amps. I wasn't sure if this meant 2a max or 2a minimum. I assumed it meant 2a maximum.

[mcshaner2k]

I may have solved my problem. Looks like the contact rating of this relay is .5a, somehow I missed this. My transformer doesn't have enough juice to activate these relays.


http://www.mouser.com/Search/m_ProductD ... o1Dw%3D%3D

[John_P_WI]

Um, no. The relay that you linked only has a power consumption of 150 ma, on a dumble circuit you will never see anything near the switch rating of 0.5 amp.

From experience, the 5 volt -H version of the same relay + LED only pulls 0.08 ma.

Either, you have the flyback diode backwards, a wiring error, or your power supply is current limited / missing a ground. Make sure the diode band (cathode) is to the positive side of the relay switch wiring and your grounds are in place. Honestly, reading through the threads it sounds like everything is floating without a ground reference.

Start at the ps and remember for analog circuits you need power, ground, and signal - in this case a switch contact.

[mcshaner2k]

Um, no. The relay that you linked only has a power consumption of 150 ma, on a dumble circuit you will never see anything near the switch rating of 0.5 amp.

From experience, the 5 volt -H version of the same relay + LED only pulls 0.08 ma.

Either, you have the flyback diode backwards, a wiring error, or your power supply is current limited / missing a ground. Make sure the diode band (cathode) is to the positive side of the relay switch wiring and your grounds are in place. Honestly, reading through the threads it sounds like everything is floating without a ground reference.

Start at the ps and remember for analog circuits you need power, ground, and signal - in this case a switch contact.

I'll check this out. Thanks for your help!

[mcshaner2k]

Turns out I was testing the relay poles incorrectly...

They're working as they should. Thanks again