4027 as latching flip flop and resettable

ScottWang

Joined Aug 23, 2012
7,398
IF you want CD4027 have the toggle switch functions, then you can do like this to try:
1. Disconnect CLR(Pin 4) from GND.
2. Add Reset Switch - Add one more input circuit, as one switch, one 1N4148, two Resistors, one cap, and connecting to CLR(Pin 4).

Also you can try to use like this:
1. Disconnect CLK from input circuit, and connecting CLK to GND.
2. Disconnect PR(Pin 7) from GND.
3. Connect the input circuit to PR(Pin 7).
4. Disconnect CLR(Pin 4) from GND.
5. Add Reset Switch - Add one more input circuit, as one switch, one 1N4148, two Resistors, one cap, and connecting to CLR(Pin 4).
 

Wendy

Joined Mar 24, 2008
23,421


OK, this is a revamp of the changes shown. This latch has a Set input, the output of the 555 will go high if the Set input is high. Just shown to show what/why I did what I did.

It may not be needed, but look at R7, which is not in your schematic.
 
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Thread Starter

chrischrischris

Joined Feb 18, 2012
313
Bill, you did it. Excellent! :):):)

I didn't need to use the 4027 after all. Your mods to the existing 555 has done the trick. Thanks again.
 
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