Timed Trigger

311

05:57:48

Timed trigger utilizing op amp and RC network.  5RC (R in ohms and C in farads) gives charge time, decreasing and increasing ohms and farads will respectively decrease or increase charge time. Hit switch and watch as the voltage across capacitor / op amp input rises until it reaches 90 percent of Vcc then triggers.  

Pretty useful, you could flip a switch knowing it will trigger a set time later. The load in this example is an Led, driven by a transistor. 

The capacitor charges through the 47.7k Resistor and the potentiometer acts as a voltage divider ;setting the trigger point. 

published 10 years ago

ianperkins

10 years ago

I used and will use again, this as my fail safe for remote detonation of large fireworks from a distance. This was in between the receiving end of detonator and its power source. Kept me safe from noise, interference or malfunctions setting off my wireless rig before i was safe distance away. HAPPY 4TH GUYS!

yereon

10 years ago

Awesome. This has helped me a lot.

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