clamping diodes
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=125298
Printed Date: October 31, 2024 at 6:53 PM
Topic: clamping diodes
Posted By: resquchas
Subject: clamping diodes
Date Posted: December 28, 2010 at 2:15 PM
any ifo on how to set up a clamping diode using 1n4004 and a zener diode. I was reading that the zener can speed up and prevent tacking of the contacts which could reduce the life of the relay. how much life reduction has been noticed if any. is this just theory? I want the most reliable method possible. what i saw was that a simple reverse biased diode across the coil can lead to the contacts even bouncing together. Granted stopping the massive voltage spike but decreasing the life of the contacts. any thoughts?
------------- The RIGHT way is the ONLY way.
Replies:
Posted By: howie ll
Date Posted: December 28, 2010 at 6:10 PM
In practice a diode across the coil contacts should STOP bounce, surely the zener diode is only there fore voltage regulation, come on in Oldspark, Dualsport etc.
------------- Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: resquchas
Date Posted: December 28, 2010 at 6:24 PM
if you have never had any reliability issues then i am not gonna worry about it. I try and make relays easy to get to but sometimes not practical and wanted to make it perfect.
------------- The RIGHT way is the ONLY way.
Posted By: howie ll
Date Posted: December 28, 2010 at 10:43 PM
AS a point of interest, German* made Bosch, US made Honeywell and Amp/Tycho and Japanese Omron and Panasonic are rated for 15 million + cycles.
*Current Bosch are apparently Chinese and not so good.
------------- Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: resquchas
Date Posted: December 29, 2010 at 10:03 AM
15 million should do it i would think. i might have to switch my supplier.
------------- The RIGHT way is the ONLY way.
Posted By: oldspark
Date Posted: December 29, 2010 at 7:07 PM
The zenor shouldn't be required - and a series resistor is required for that.
The only other possibility would be to clamp the +ve voltage spike (not the reverse or -ve spike), but how often is that done? (at the relay).
Sorry for my slowness - we've been snorkling with the rays....
Posted By: resquchas
Date Posted: December 29, 2010 at 7:57 PM
rescue diver myself so understand the whole snorkeling thing. so in your opinion best practices would just be the 1n4004 across the coil and call it a day?
------------- The RIGHT way is the ONLY way.
Posted By: oldspark
Date Posted: December 31, 2010 at 5:47 PM
Yep - any 1N400x.
Posted By: resquchas
Date Posted: December 31, 2010 at 7:12 PM
thanks everybody
------------- The RIGHT way is the ONLY way.
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