I need a timer (555?) that cycles, 1 second off, 10-50 milliseconds on, repeat forever

Thread Starter

Hamlet

Joined Jun 10, 2015
308
I need this to drive a mosfet, 10A load. Do I need two NE555, or can I do it with one device?
 

wayneh

Joined Sep 9, 2010
16,390
I need this to drive a mosfet, 10A load. Do I need two NE555, or can I do it with one device?
Does it have to be a 555? Control in the 1-5% duty cycle range might be better with an op-amp square wave generator. That trick is commonly used for full-range PWM control.
 

Thread Starter

Hamlet

Joined Jun 10, 2015
308
Does it have to be a 555? Control in the 1-5% duty cycle range might be better with an op-amp square wave generator. That trick is commonly used for full-range PWM control.
Well, I have a bunch of those 555's, but I also have a few other cmos/Lm/Op etc. devices. What I am doing is making a powerful current driven electric fence charger for my garden, a "weed-burner" if you will, and I only want to drive it "on" for a short period, for safety, my safety. My previous attempt worked great, but a herd of elk moved in this past winter, and stayed. They go right thru my h-v fence (useless when rain torments my insulators) so I need something more authoritative, but I don't want to run 30mA on full-time, as that is unsafe.
 

Rich2

Joined Mar 3, 2014
172
I made a low duty cycle 555 circuit last year, it flashes a high power LED just briefly every 3 seconds or so. I made it to put next to my laser level so people would see it and not trip over it. I can look the diagram out if you think it will be of use to you.
 
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