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Update: A year since I first posted this... Still no update to the 555 simulation?
Original Post:
The light should come on after a delay of less than a minute.
Leave the switch between Thr(pin6) & Dis(pin7) closed for the demonstration of the first 3 issues! Always start the simulation with the battery switch open, or additional issues crop up that will disguise what I'm trying to demonstrate.
It would be preferable to run the simulation at 1s/s. Unfortunately EC is having problems with the simulation. If you close the switch with the simulation running at 33ms/s or less it works fine. But...
Issue 1: If you close it with the simulation running any faster, the capacitor on the green line will never charge. It only seems to matter what simulation speed is set when the battery switch closes. Increasing or decreasing after it starts does not help or hurt. So start it at 33ms/s, then spin it up to 1s/s to see how it functions in real time. When the green line capacitor reaches 6V, the light will illuminate.
Issue 2: You will also notice while you wait for the capacitor to charge on the green line, a ghost current is created by the 555 Vcc(pin8) through the bulb. This current should be coming from the battery, of course.
Issue 3: If during the charging of the capacitor (wait for around 4 or 5 volts to make it more evident) you open the battery switch, you will notice that the charge on the capacitor immediately flows out through Dis(pin7) to ground. This does not happen on real 555 chips. On a real 555 chip, when power is removed from Vcc(pin8), Dis(pin7) remains isolated from ground.
Issue 4: Again allow the capacitor to charge to around 4 or 5 volts to make my point more evident. This time open the switch between pins 6 & 7. Now open the battery switch to depower the 555. As you can see, the capacitor's charge only drains through Thr(pin6) very slowly to ground. In real life all charge above approximately 1.5V will drain very quickly to ground, and then the remainder will flow very slowly.
All 4 of these issues have created problems for me over the last few months that I have been using EC to design a timer. I have been able to recognize the errors with bench testing, and work around them, but it would be great if you could figure out a way to improve the simulation to more closely resemble the 555. Thanks so much for your help! Overall this is a great application!
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