555 IC 1 minute delay timer not working in simulator

Question

I have a problem in Falstad that when making a 555 IC based signal delayer that should delay a power-off of a certain device, that the whole circuit behaves really weird and doesn't work as stated by multiple people who tried it out on the internet. Why doesn't it work in the sim?

There is no delay, it turns on as soon as the switch is toggled. When applying putting there a diode it seems to behave very strangely.

here is a link to captured screen video of the behavior I am facing: https://youtu.be/XtibAHLGqTE

Here is a link to the schematic I was coming out of (but there are many like it): https://elonics.org/adjustable-auto-on-off-delay-timer-circuit-using-555/

Answer 1

The simulation is actually wrong. But likely the component values are not entirely well thought anyway. For an ideal 470 uF capacitor it will work, but for a real-world 470uF electrolytic capacitor with leakage current, the value is just unrealistic for real world purposes.

On a real chip, if trigger is active, i.e. low, then threshold voltage is irrelevant, and the output is always high, and disharge pin will be always off. It means that trigger pin overrides the discharge pin.

The point is, don't keep trigger pin low. Pulling trigger low will trigger the delay, start charging the capacitor and set output high, but trigger must be released before capacitor threshold voltage is reached.

It would not work in real life either, if you keep trigger low permanently. And it would likely be affected by non-idealities of real world electrolytic capacitors too, likely requiring much longer time than calculated.