Advice on 555 timer

Thread Starter


Joined Jan 4, 2015
Just did a circuit for a 555 timer that I could use some advice on. What I'm looking for is when 12 volt DC is applied and constant until voltage is removed my circuit works for approx 3 to 5 seconds. Then it is repeated when power is removed and applied again. I have tried it on bread board and works like I want. But a beginner I would appreciate a second look to see if there would be any long term issues.

Also where I have light on the diagram I wondering if I should do a relay seeing I'm looking to hook up a battery powered spark Igniter from home Depot to ignite propane gas from a solenoid. Unless someone can send me in the right direction to build my own. Also wondering if there's a way to hook up a pointiometer to change duration.

I have another thread here that I'm using it for. I'm getting rid of the thermocouple and going with an igniter instead of pilot.


Any advice would greatly be appreciated. Thanks




Joined Oct 2, 2009
Try this. D1 and R2 is there to reset the timing network when power is disconnected. Even a brief interruption of power resets the timing network. You may be able to delete R2 if there are other loads powered from the switched-12V-rail V(s12v).

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Joined Aug 23, 2012
Your attach is too large, before you upload the file, please compress to 800x600 or 600x480, or 1024x768, this photo I already compressed it from 1.3Mb to 61Kb, if the file size too large then it will be affecting the members to connecting to the forum.

Thread Starter


Joined Jan 4, 2015
OK. So this is what is going on. The timer circuit I made worked pretty good(for a few hours) lol. No issues, except that it would be my best guess that every time the bbq igniter was being fired it was sending voltage back though ground and eventually killed it. So I'm looking for some help in figuring out the best way to either make a ground loop or just some how isolate the incoming voltage through ground with diode or something. Here a pic of the control box I fabricated and wired up. IMAG0230.jpg