Joule Ringer!

[hartiberlin]

Sorry Conrad, I was wrong.
The channel 2 must not be inverted.

As it is shown it is okay.
Thanks for showing the groundline.

[hartiberlin]

@xee2
yes, what the second spike is is mysterious.
For better efficiency this should be suppressed.

Conrad, can you do please again a 1 channel scopeshot
with a deflection of 2 or 5 usec
just showing the voltage at the tube ?

Then we can compare this to the input current / cap voltage shot
and can say more about the timings.

Many thanks.

Regards, STefan.

[conradelektro]

Reason for the second trigger (bump) is may be the 100 nF (or 200 nF) and 500 K combination on the base of the transistor.


When I change the capacitor from 200 nF to 100 nF the form of the scope shots changes.

The capacitor is absolutely necessary, without capacitor (only 500 K) the circuit stops. This capacitor-resistor combination (or a bifilar coil terminated with 1N60 diodes) is the whole point of the Joule Ringer. Otherwise we go back to an ordinary Joule Thief.

Conrad

[hartiberlin]

Hi Conrad, yes, this second spike could depend
on the ringing of the basis coil with the 200nf/100nF cap.

Do you have a pulse generator ?

Then one could just see with a pulse generator instead
of the 200nF/500KOhm parts to pulse an about 1 usec pulse
to the basis of the darlington and see, how the cap voltage behaves...


It seems that short current spikes do not discharge the electrolytic
cap so much...
Maybe the cap wants to keep its voltage level and somehow recharges
itsself from the environment or something simular.

Regards, Stefan.

[hartiberlin]

It would be really interesting to see what happens,
if the transistor is just pulsed with a pulsegenerator that
has 2 Mikroseconds Ontime and 3 milliseconds  Offtime.

This will be a frequency of around 333 Hz with extremly short ontime only..

How fast will the cap discharge then ?
Many thanks.