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defective relays?

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=127993
Printed Date: May 01, 2024 at 9:07 PM


Topic: defective relays?

Posted By: replica9000
Subject: defective relays?
Date Posted: July 20, 2011 at 10:04 PM

I've recently bought two DF005 "Baja Tough" relays. I think they may be defective. When I connect power to pins 85 & 86 I can here the relay switch, so that seems to be fine. When I connect LEDs to pins 87a & 30, I have nothing. When I connect something to pins 87 & 87a, the LEDs light up. Shouldn't that be impossible to complete a circuit using only pins 87 & 87a?



Replies:

Posted By: oldspark
Date Posted: July 21, 2011 at 2:11 AM
Correct. But check your circuit - 87 & 30 should complete the LED circuit when the relay is on, as should 87a & 30 when off. IE = +V to LED with its Kathode to 30 to (87 or 87a) to GND etc.


But I wonder why you are using a relay for LEDs? A single string of LEDs is about 20mA. The relay (coil) is probably up to 250mA.




Posted By: i am an idiot
Date Posted: July 21, 2011 at 3:14 AM
What are the chances that you have a single pole single throw relay (2 terminal 87s and no 87a)?
what are the chances you are looking at it upside down?




Posted By: replica9000
Date Posted: July 21, 2011 at 8:31 AM
The set up I have is the LEDs come on with the parking lights, when the parking lights are on, and I use the turn signal, the LEDs will blink (turn off with voltage from turn signal).

So power from parking lights go from pin 87a to pin 30 (NC), lighting up LEDs, when pins 85 & 86 receive power from turn signal, relay should switch on and stop connecting between pins 87a & 30 (NO), allowing LEDS to alternate blinking with turn signal.

When I connect power from the parking lights to pin 87a, and positive to the LEDs to 30, they don't work (yes they are grounded).

Right now I have it set up turn signal positive to pin 86, 85 connects to pin 87, and 87a has the parking lights with 30 connecting to the LEDs.

If I leave pin 87 empty, and connect 85 to ground, I hear the relay switch, but nothing lights up.

I hope I'm not confusing anyone.




Posted By: i am an idiot
Date Posted: July 21, 2011 at 8:44 AM
To energize a relay, you need power on 86 and ground on 85.




Posted By: replica9000
Date Posted: July 21, 2011 at 9:02 AM
I've done that, and the relay does switch. But the LEDs don't light up unless I connect pin 85 to 87.




Posted By: i am an idiot
Date Posted: July 21, 2011 at 9:38 AM
Using Microsoft Paint, can you draw a diagram of the relay, the LED and all associated wiring? Save it as a GIF file and upload it here. Or I can give you an e-mail address in which to send it.




Posted By: oldspark
Date Posted: July 21, 2011 at 10:12 AM
You need to connect the relay coil between the parker +ve and turn signal.
Then the relay will turn the LEDs on when the parkers are on & flashers off, or the flashers are on and parkers off.

The relay (#30 & #87) can either ground the "hot" LEDs, or supply +12V to grounded LEDs.




Posted By: replica9000
Date Posted: July 21, 2011 at 10:32 AM
Sorry for the late reply. I just bought two new relays, BWD R3177, and they work. I connect power to pin 87a, and the LEDs on pin 30 light up. And with power supplied to pin 86 and 85 to ground, the relay switched, blinking the LEDs, this works with pin 87 empty. So the DF005 relays must be defective.




Posted By: replica9000
Date Posted: July 21, 2011 at 3:32 PM
For anyone still interested, this is the finished product of my relay setup.

What this does is.... (2 relays per side)
With parking lights off:
Power supplied to LEDs with lock / unlock / turn signal.

With parking lights on:
Power supplied to LEDs from parking lights.
When turn signal active, cuts power supplied from parking lights during each blink of turn signal.


posted_image





Posted By: dualsport
Date Posted: July 26, 2011 at 6:13 AM
If you have the standard incandescent bulbs on the turn signal and parking light lines in addition to your LED strip lights, you can simplify it and use a single relay, with parking light power going to terminal 30, the LED strip to 87, and the coil inputs connected to the turn signal input and parking light input.

Whenever either the parking light or turn signal lights are on, the relay will energize and light up the LEDs, but when both are on at the same time, the relay will deenergize and leave the LED off, which is what you wanted.
Just use a non polarized relay without any internal suppression diodes.
This uses the low impedance of the incan lamps to act as a virtual ground for the relatively higher impedance of the relay.   If you've removed the incan lamps then this wouldn't work-




Posted By: replica9000
Date Posted: July 26, 2011 at 11:40 AM
Thanks for the suggestion. I do have the normal incandescent bulbs in right now, but I may be changing those soon to LED, so everything flashes at the same rate.





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