New Relay Diagrams

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=142642
Printed Date: May 04, 2024 at 4:29 PM

Topic: New Relay Diagrams

Posted By: mpheyse
Subject: New Relay Diagrams
Date Posted: February 21, 2017 at 10:50 AM

Currently there are four Constant to Momentary Output relays setups on Relay Diagrams page. The four cover the range of input to output polarities (-/- -/+, +/-, and +/+).

They all behave they same, and looking at just the positive input pair (for simplicity of this description) it operates on a principal that is called Rising Edge Triggered meaning that it only fires off (sends a pulse) when the switch line goes upto +12v (when switch line gets connected / turned on).

I think that there should be another set of four diagrams that are Falling Edge Triggered. Or a Relay that only fires off (sends a pulse) when the Switch line stops being +12 (when switch line gets DIS-connected / turned OFF)

Currently I'm home sick, and my head head hurts. The only thing I can think of is to use a second relay's NC terminal to invert the state (connected/disconnected) of the switch line before feeding it to the momentary relay. Can we do better, Simpler? (i.e. only one relay)

In either case, mine or a better one should be added to the relay Relay Diagrams page

Since this is mostly a Car forum, Here is an example for a Car based use.

On older cars with out fancy automation electronics... when Key-on stops driver turns off the car (switch line disconnected) a pulse is send to the door locks (unlock) because the driver is getting out soon.

Replies:

Posted By: the12volt
Date Posted: February 21, 2017 at 11:13 AM

https://www.the12volt.com/relays/relaydiagram7.html

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the12volt • Support the12volt.com

Posted By: the12volt
Date Posted: February 21, 2017 at 12:05 PM

You are correct. Two relays would be needed for each of the four diagrams you requested if the source does not change polarity and simply opens (switch line gets disconnected). In my diagram I linked to above, the switched source changes polarity.

BTW, thanks for requesting these. I'll try to get to them soon.

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the12volt • Support the12volt.com

Posted By: the12volt
Date Posted: February 21, 2017 at 3:29 PM

Here's one of the four. https://www.the12volt.com/relays/relaydiagram70.html

I'll draw the others within the next day or two.

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the12volt • Support the12volt.com

Posted By: the12volt
Date Posted: February 21, 2017 at 3:52 PM

One more... https://www.the12volt.com/relays/relaydiagram71.html

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Posted By: the12volt
Date Posted: February 21, 2017 at 4:31 PM

Here's three and four...
https://www.the12volt.com/relays/relaydiagram72.html
https://www.the12volt.com/relays/relaydiagram73.html

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