Kapanadze Cousin - DALLY FREE ENERGY

[verpies]

Try as I might I just can't get that 15 micro S distinction!! I have been pulsing the Piezo with an adjustable PWM that has the facility to go from 0-100% pulse width. I could see the decay in the receive Piezo but using a slow time base ( low PRF) the minimum distance between plot lines is 50 micro S!! Is this something we need to see or can we take it as read?

That's nothing that can be ignored. If not cleared up, it will come back and bite us later.

Maybe the piezos themselves introduce a delay.  What do you see on the scope when you press the two piezos together directly face to face with a paperclip (maybe with a mica spacer but without a ferrite core) ?

PWM generator should be set to 1kHz PRF and the duty cycle as low as you can get (e.g. 0.001%).
Of course, scope Ch1 across the transmitting piezo and Ch2 across the receiving piezo.
Triggering from Ch1. Initially horizontal timebase set so only 2 transmitting pulses are shown on the scope's screen and set faster timebase later to magnify it ( make sure the timebase is in the calibrated state!!! e.g. 100μs/div exactly ).

[Grumage]

That's nothing that can be ignored. If not cleared up, it will come back and bite us later.

Maybe the piezos themselves introduce a delay.  What do you see on the scope when you press the two piezos together directly face to face with a paperclip (maybe with a mica spacer but without a ferrite core) ?

PWM generator should be set to 1kHz PRF and the duty cycle as low as you can get (e.g. 0.001%).
Of course, scope Ch1 across the transmitting piezo and Ch2 across the receiving piezo.
Triggering from Ch1. Initially horizontal timebase set so only 2 transmitting pulses are shown on the scope's screen and set faster timebase later to magnify it ( make sure the timebase is in the calibrated state!!! e.g. 100μs/div exactly ).

Dear Verpies.

I hope this looks ok?? 

Cheers Grum.

[verpies]

I hope this looks ok?? 

What is being measured?
Why is the rise time of the upper trace so long?

[Khwartz]

https://www.youtube.com/watch?v=lEa_B-zYObc&feature=youtube_gdata_player

"The load is part of the ZPE tuning" - Selfonlypath.

[verpies]

"The load is part of the ZPE tuning" - SelfonlyPath.

Especially when using Load Controlled Oscillators (such as the Mazzilli circuit)