Why doesnt it oscillate

122

02:19:33

I saw a video where it worked, so why doesnt it work here ?

published 1 year ago

BraydanD

1 year ago

The fix is to make those two base resistors a much higher value, say 10K ohms, and if you want the LED to glow brighter, reduce its current to 5mA

BraydanD

1 year ago

Also set the simulation speed to 100ms as well and if you are using a phone or tablet, physically shake your device to put some noise into the circuit to start it oscillating, if you are on pc then click and hold anyhwere on the workspace and shake it to inject noise

pedroretro

1 year ago

Set these resistor values from left to right: 1k 100k 100k and above the LED it will be 100 ohms

ati14

1 year ago

Thanks ! Now it work

SleepyMolecule

1 year ago

It's interesting how noisy it is, I'm not sure why tbh. But when you have randomness it's usually due to the simulation not being the right speed. I put a 10hz 1v sine wave source in, set the resistors to 1k 20k 20k 500 and made the led 2v 5ma and it was much more stable. The important part is, the simulator needs to be fast enough to represent oscillations (in this case the spikes from capacitors on switching) or you get incorrect results, like randomness or some oscillators won't reach their full values

SleepyMolecule

1 year ago

Note the sine wave source doesn't need to be connected to anything. It just sets an upper limit and forces the simulator to a fixed shortest (fastest) time step

BraydanD

1 year ago

@SleepyMolecule wouldn’t the simulation speed by itself be enough to keep the simulation steady? I do get what you mean with the sine source, it is smart.

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