<p dir="ltr">John, a question that came up in IRC last week was: why not just double the turns ratio on the coil, rather than add the doubler on the high-side?</p>
<p dir="ltr">I'd also like to see a screenshot where the pulse generator has more delay between pulses, so we can really see some dead time padding the edges.</p>
<p dir="ltr">Looking good otherwise :)</p>
<p dir="ltr">-Nathan</p>
<div class="gmail_quote">On Jun 21, 2016 6:28 PM, "John Griessen" <<a href="mailto:john@industromatic.com">john@industromatic.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">The yardboard has been hooked up and given a mild amount of volts and observed<br>
with a 100X probe good to 1500 Volts and shows normal good transformer action,<br>
but the volt doubler goes negative and no doubling either. I must have not gotten the polarity of<br>
transformer windings right. Tomorrow I'll be swapping and retesting.<br>
<br>
Volt doublers like this, (from a junk laser printer) only do one direction. If you feed them with the wrong<br>
polarity voltage, no doubling. Tomorrow will be a full day of work on this with the aim of getting<br>
the transformer turns ratio confirmed with high volts, and volt doubler observed to do something, then adding<br>
load resistance of 30k Ohms, then cranking up input volts some, then using the 7kV probe to observe how high it will go<br>
with doubler action.<br>
<br>
In the photo, the top trace, (5V per division), is the input to the transformer -- one wire of its<br>
input windings connected to DC volts in, the other end pulled down by the<br>
transistor, (which can be driven by a microcontroller GPIO pin.<br>
<br>
The middle is transformer output, 500V per division.<br>
<br>
The bottom trace is a current measuring shunt on the input-winding/transistor<br>
path to ground -- don't know the scale at them moment.<br>
<br>
John Griessen<br>
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