[Open_electroporator] Culture Shock yardboard testing

[John Griessen]

The yardboard has been hooked up and given a mild amount of volts and observed
with a 100X probe good to 1500 Volts and shows normal good transformer action,
but the volt doubler goes negative and no doubling either.  I must have not gotten the polarity of
transformer windings right.  Tomorrow I'll be swapping and retesting.

Volt doublers like this, (from a junk laser printer) only do one direction.  If you feed them with the wrong
polarity voltage, no doubling.  Tomorrow will be a full day of work on this with the aim of getting
the transformer turns ratio confirmed with high volts, and volt doubler observed to do something, then adding
load resistance of 30k Ohms, then cranking up input volts some, then using the 7kV probe to observe how high it will go
with doubler action.

In the photo, the top trace, (5V per division), is the input to the transformer -- one wire of its
input windings connected to DC volts in, the other end pulled down by the
transistor, (which can be driven by a microcontroller GPIO pin.

The middle is transformer output, 500V per division.

The bottom trace is a current measuring shunt on the input-winding/transistor
path to ground -- don't know the scale at them moment.

John Griessen
-------------- next part --------------
A non-text attachment was scrubbed...
Name: yardboard-2.jpg
Type: image/jpeg
Size: 76959 bytes
Desc: not available
URL: <http://cibolo.us/pipermail/open_electroporator/attachments/20160621/27ee978c/attachment.jpg>