I'm trying to make a simple astable circuit. It should be one of the easiest ones in history of electronics, but I can't figure out what's wrong with my design:
simulate this circuit – Schematic created using CircuitLab
The output voltage remains too low. About 1.5 V peak to peak.
(For my application this is less important, but maybe it could be useful to note also that the calculated frequency differs from the real one of about 30 KHz.)
I tried a different power supply and also a different ne555 IC.
Could someone please explain to me why the voltage is so low?
Best Answer
I think that your problem might be that you are using a X10 scope probe but the scope thinks that you have a X1 probe attached.
The output of a NE555 doesn't go all the way to Vcc - there is an internal voltage drop of more than 1 Volt.
If you look closely at your scope waveform, I see an amplitude of about either 0.8V (X1 probe) or 8V (X10 probe). I'm putting my money on X10 probe.
It is also possible that the probe compensation isn't adjusted properly.
In other words, I think that you are dealing with a measurement problem rather than a circuit problem.