Push on, push off

Thread Starter

FroceMaster

Joined Jan 28, 2012
565
Hi.
Have found this online and have modified it a little.
As far as i can see the function is.
When pust on "S1" the state out of "IC1B" change from 0v to 12v. ?
And by this i can feed an transistor that "pull" my relay ? Coil 390 Ohm
And when i press button again it change state back to 0 v ?

Just to be clear ,
And the Resistor R3 ? is value ok ?

Rgds
Sten
 

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dl324

Joined Mar 30, 2015
10,072
It is difficult to read circuit intent from your drawing style.

This is what I transcribed (substituting inverters for NANDs) and put in a more conventional layout:
1573749129954.png
The circuit has some issues.
  1. You're loading the output of a logic gate that you need to maintain proper logic levels.
  2. You don't have a snubber diode on the coil.
  3. C2 might need to be larger. I have used this circuit and typically use 100nF.
What is the coil resistance?
Use the unused NAND gates to buffer the output of the flip flop.
 

dl324

Joined Mar 30, 2015
10,072
I think yours is a different circuit, which will work properly. The original circuit has one side of the switch connected directly to +12v, so it will latch on but not off.
Thanks, I missed that and automatically corrected the error in the original schematic.

The original author has poor style:
1573750390742.png
 
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