I am trying to create a long high pulse (around 10 minutes), then falling
edge. Then have the process start over.
I did not find any astabel circuits that could produce a very long pulse
without additional ICs. I did find some long pulse monostable circuits, but
am having trouble getting the timing to be consistent.
In my sample circuit I have decreased the RC values just for testing.
Sometimes the pulses are consistent, other times they appear to be at fairly
For testing I am using 22K for the resistor, and 33uf for the cap
My actual values will be 1.6M and 33uf
My pinouts look like this:
Pins 1,2,5 are grounded
Pins 1,2,5 also go to the - on my cap
Pins 4,8 +5V
Pins 6,7 go through my resistor to +5
Pins 6,7 also go to the + on the cap
Pin 3 is my output
(sorry I tried to draw a schematic, but it did not come out too well)
Why is the timing in my circuit not stable? Is there a better design I can