PWM - Dutycycle affecting frequency?

[Acetronics2]

Hi,Flotul

Did you read what Melabs tell about PWM wave shape at $ 5.51 ??? ( First of all ... I thought you talked about Hpwm !!! ( RTFQuestion for me ...).

I think your scope gave you the Low. Freq. ENVELOPE ot the signal ... may be ( surely ...) you should have a different picture on an analog scope !!!

Digital scopes are fine ... yes, but with a comfortable sampling frequency !!!

~ 200 Euros ( 180 with your 20% "discount" ... ) scopes have their limits ... you just found some ...


You won't have a neat wave shape with PWM ... Never. Try to borrow a 50 or 100 Mhz analog scope ... to see what PWM looks like.

Alain

[flotulopex]

You might be right: my cheap oscillo has its limits.

I can grab a LeCroy at the office but to me, its like a "Jumbo Jet 747" (must have at least 30 contextual buttons on the front pannel and a 3 kilos user manual...).

But maybe I'll try this anyway.

Nothing is impossible...