Gürteltiermodulation

Problem is, an astable 555 timer is a VCO (voltage controlled oscillator), meaning that the frequency shifts with different supply voltages. So you basically end up with an FM transmitter, with a lot of residual amplitude modulation.

Buggzy saw a change in frequency and his conclusion is: "555 is a VCO". No its not a VCO by default! And the frequency does NOT change with different correct supply voltages! 555 charges and discharges between 1/3 and 2/3 of Vcc. The RC exponential charging does NOT care the absolut voltage! Doesn't matter for the time constant if your supply is 9V and you charge/discharge between 3 and 6V or your supply is 15V and you going up and down from 5V to 10V. Tau=RC doesn't care what voltage (as you can see from the formula for the time constant)! What buggzy saw is the reset behaviour were 555 restarts from 0V (instead of 1/3 supply) and has to raise to the upper 2/3 threshold longer then normal. However, buggzy saw that in the diagram and declares for all time - 555 is changing its frequency with different supply voltages because its a VCO. No buggzy.

That's got to be the best example of hurz correcting thee bugger yet. Bookmarking for this reason

I can imagine some Frequency jitter at the low end of the outer amplitude. There was a clean version posted recently, with an external Transistor doing the Modulation instead.

A 555 timer can be used as VCO

And the restart you talk about is exactly the thing that makes the frequency drift with different supply voltages. Yes the behaviour is not linear, but it's not AM as well, where the frequency is kept constant (more or less)

I was wondering where the pesky little hurz had gone. I haven't seen him lately in the comments

You missed me a lot, right? I have seen more incorrect information the last weeks you published, but haven't said anything and let you do your shit. But from time to time you need a reminder to not fly to high. Tipp: Read first, then ask!

No, I was actually grateful to think you were gone for good. Yeah, I'm not gonna further suit your ego idc

Conclusion as expected, buggzy declares the following bullshit as fact "555 timer is a VCO (voltage controlled oscillator), meaning that the frequency shifts with different supply voltages"