Dark Detector On + Timed On (Outdoor Lamp)

Thread Starter

kcarring

Joined Jan 22, 2011
38
I have been reading a lot of threads here, and elsewhere regarding the use of 4060 IC's, and such for delay timers.

I have built a circuit that uses a 555 dark detection circuit by Tony Van Roon that I am very happy with.



In day mode, idle, it consumes .1 mA. While supplying the voltage to my mosfet, (running the lamp) - the 55 circuit, itself, uses 6.7 mA.

So I am happy with those numbers and it behaves perfect.

My question is this:

The lamp runs all night. How can I use a 4060 or something to make the lamp only run for 2-6 hrs.

Thanks
 

crutschow

Joined Mar 14, 2008
24,055
Use the 4060 as a timer to bring the Reset input low on the 555 at the time-out. You can add a CD4009 inverter to invert the output to give a low to the 555 Reset input.
 

Thread Starter

kcarring

Joined Jan 22, 2011
38
Wouldn't that just start the whole cycle over, the dark detector once again sees that it is still dark, feeds power to the gate, turns on the 4060... ??
 

crutschow

Joined Mar 14, 2008
24,055
Wouldn't that just start the whole cycle over, the dark detector once again sees that it is still dark, feeds power to the gate, turns on the 4060... ??
Good point. You need some memory, such as a flip-flop (latch) at the counter output that is set by the counter to keep the light off until it is reset for the next cycle by the light reappearing.
 

tracecom

Joined Apr 16, 2010
3,944
You can add another 555 monostable between the output of the dark detector and the MOSFET, but I suppose you have thought of that.
 
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