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Single Push button to ON and OFF a Bulb using Ladder Logic

Learn how to use Single Push button to ON and OFF a Bulb using Ladder Logic in programmable logic controllers (PLC) control system.

  • I0.0  : Input Push-Button (Normally-Open)
  • Q0.0 : Output Coil (Bulb)
  • Q1.5 & Q1.6 : Flags

Single Push button Ladder Logic

As soon as the push button I0.0 (N-O) is pressed ,it becomes N-C and coil Q1.5 (flag) is energized. The another flag Q1.6 will not energize as the output coil contact  Q0.0 is N-O, which breaks the circuit to the flag Q1.6.

As soon as the flag Q1.5 is energized ,the contact Q1.5 (N-O) becomes N-C and out bulb coil Q0.0 gets energized and bulb becomes ON.

Single Push button to ON and OFF a Bulb using Ladder Logic

Now, if the push button is released the coil Q0.0 will remain energized because of latching applied as latch contact Q0.0 (N-O) in last rung. To switch off the bulb the push button is again pressed which closes the N-O contact of o/p coil Q0.0 and energizes the flag coil Q1.6.

Due to energize of flag Q1.6 , the N-C contact of this flag in last rung becomes N-O  and as a result of this ,the last rung goes false and output coil Q0.0   is de-energized and bulb goes OFF.

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3 comments

Jakaria December 18, 2019 at 9:03 pm

Very nc

Reply
Sergey January 15, 2020 at 6:01 pm

DO not fill people, this will not work.

Reply
Raj January 16, 2020 at 10:38 pm

This will not work….gave a try

Reply

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Single Push button to ON and OFF a Bulb using Ladder Logic

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