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adjustable pulse relay trigger

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=120580
Printed Date: May 20, 2024 at 5:45 PM


Topic: adjustable pulse relay trigger

Posted By: lostyankee
Subject: adjustable pulse relay trigger
Date Posted: March 07, 2010 at 6:42 PM

 Looking for advice on building an adjustable pulse trigger for a relay operating a 180 watt fuel injection line heater in a 2003 VW Golf diesel in a vegie oil conversion. Off the shelf units do not have the BTU or control I desire. Thermostat responce time is too large to keep the fuel line in the 190 - 220*F range.  Something like 20% increments would be fine as in 20 pulses per second, 30 pulses, ... full on.

What off the shelf relay will handle the amount of cycles needed for 50 hours operation per year x several years? I believe the relays I'm currently using have a 10K cycle life. Current system cycles in a 60 degree range.

My goal is constant temperature. I do not want the heat the fuel before past 80*F before the injection pump like many kits do.

Advice?



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No politicians were saved in the making of my movie.



Replies:

Posted By: oldspark
Date Posted: March 07, 2010 at 7:07 PM
I think you mean or are after a PWM circuit with FET output etc to control a heater.
You won't be using relays for sub-second cycles (and maybe not for many cycles on heaters anyway).

There are various temp control circuits around....

(Alas I'm operating remotely due to a windoze crash so I can't access my info for a while...)




Posted By: KPierson
Date Posted: March 07, 2010 at 7:40 PM

Also look in to solid state relays - quick switching and no contacts to wear out.  Solid State relays are used frequently in heating applications.



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Kevin Pierson





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