⭐️Timing circuit with standby LED⭐️

Credit to @2ctiby whose assistance is greatly appreciated. I previously published this circuit without an additional LED which I've included in this publication. Red LED = Timer in standby mode. Green LED = Tumer is activated. Press the NO push button to start. Notice the tall vertical blue current spike on the scope ...that is the ON start time marker. Watch the scope until the mosfet suddenly switches the LED off with a sudden vertical orange spike. That is the OFF end time marker. Hit your Pause button when that blue vertical start line is seen at the far left of the shown 5s scope bar. Notice that the time duration for that blue vertical ON start, to that orange vertical OFF end, is almost exactly 5s... ie the length of the shown 5s scope bar here. The mathematical time to describe that duration (seen as the discharge blue current curve) is: 5 × R × C ie: 5 × 200k × 5uF ie: 5s [ R × C is called the time constant, tau ... but remember that we need to multiply that tau by 5 to give us the whole curve of the discharge time from ON to OFF approx ... as seen by the blue current trace.] 5RC ... is the thing to remember for these calculations, but the Mosfet settings really need to be adjusted too (which I did here), if this sort of precision is to be seen in a mosfet circuit display. Sim speed alterations are just a way of seeing things in slow motion. The scale and maths mentioned above give the real result, rather than trying to match by counting your own clock seconds outside of EC. Enjoy...😎

published 1 year ago