[Open_electroporator] Culture Shock yardboard testing

[John Griessen]

On 06/25/2016 07:29 PM, Nathan McCorkle wrote:
> Hmm, aren't the diodes going to dump before you turn on the pull transistor, making the transistor ineffective when you do finally
> turn it on (assuming these are zener diodes)?

They are just HV diodes in the doubler.  If you mean the ones next to the two transistors,
no, they are just diodes also, and they are oriented opposed to the transistor turn on,
so when the transistor conducts, they do not.  They are what is called freewheeling diodes
that stop an inductive spike from taking out your transistors.  When this is all sized right
and not near saturation of transformer cores, a push pulse will always be followed by a pull pulse
and the durations will be shorter.  The push and pulls need to be balanced to avoid too much DC and
the resulting saturation.

In the code, (maybe later today), we'll set up a function to sequence two pulses centered always
on cycle half period with parameters of duration or pulse width;  offset from centered;
and period between pulses.  Then when you call the function with period 1 usec tapering up from zero
width 100 times, then width .45 usec 800 times, then call it with tapering down width 100 times
you have a 1 msec strong zap with a smoothed square wave shape.

Other shapes are just a pythons script rearrangement away.