Push button to power up and off

183

03:17:26

Push button for a few seconds to power up your project and do the same to switch it off.

published 5 years ago

wyoelk

5 years ago

What is this supposed to show?

Chris1960

5 years ago

Hold push button in and the led will come on after a few seconds to power up your circuit.Power comes out at the transistor emitter.Push button again for a few seconds to turn the power off at the emitter.

wyoelk

5 years ago

Is this to have a delay on/delay off circuit? Why the diode?

Chris1960

5 years ago

The capacitor must discharge through the diode and 5k resistor to be ready for the next press.

wyoelk

5 years ago

Being a polarized capacitor it will still discharge without the diode. BUT, you are correct, it keeps control of the discharge

Chris1960

5 years ago

It is supposed to discharge capacitor faster with the diode bypassing the parallel resistor but the simulator doesn't see it that way?

wyoelk

5 years ago

Because it is a polarized capacitor. Try a regular capacitor. Also if you bypass that diode and resistor to its right, it becomes a one touch on/off setup

Chris1960

5 years ago

I notice now that the capacitor discharges slower when the diode is removed.So it is having the effect that I intended.You need a fast discharge so that the button will be ready for the next press.

wyoelk

5 years ago

Yep very well done as seeing you desired a delayed on/off function everything in the circuit is necessary. Perhaps slowing down the simulator and scoping the capacitor will show what you need.

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