[Open_electroporator] Culture Shock yardboard testing

[John Griessen]

On 06/27/2016 10:28 AM, Nathan McCorkle wrote:
> Yes I can follow the timeline of development, but my reason for posting such specifications was exactly because it is different by
> 10x. It could easily be major design flaw, of course only testing will tell unless we find historical information. You also
> addressed none of what I actually asked.

Are you getting your questions answered?

" I ASKED if a topology like this could be utilized with SMALLER components, because I KNOW our target application is MUCH less 
intensive."

If you mean like cap discharge as in biorad gene pulser, yes the system I have been describing is essentially some caps on the 
output in parallel with the sample load resistance that discharge through it, and the transformer part is the cap charging 
function.  The new system is about repeated pulses to keep on recharging the caps and keep the current flowing to the load.

"it is completely due to my interpretation and feeling that my questions and discussion points went unheard and ignored, and 
ultimately unaddressed."

OK, just ask again and keep emails short or it gets confusing.  Call me on the phone any time also.

I am going to do some work soon, but here's one more thing to ponder about my approach:

About using an auto ignition coil:    http://www.gofastforless.com/ignition/howig.htm


"Inductive ignitions are self adjusting. If a 100 volt spike is needed to initiate a spark the primary will only rise to 100 
volts. The spark will then burn until all the energy in the coil is used up. The lower the voltage the longer the spark will last. 
Let's say you open up the spark plug gap and now 150 volts is required to fire the coil. When the current is interrupted on the 
primary, the magnetic field will cause the voltage to rise rapidly. The voltage will rise until it reaches 150 volts at which 
point the spark plug will fire. After the spark is started the voltage will actually drop since it takes less voltage to maintain 
a spark than it does to start one. The spark will continue to burn as long as there is energy left in the coil. Only now the spark 
duration is shorter since the spark fired at a higher voltage than before. Increasing the spark plug gaps without increasing the 
amount of energy stored in the coil can actually hurt performance. If most of the energy is used to initiate the spark then there 
will be little left to maintain it. It's even possible there won't be enough energy to make a spark in the first place. To get the 
benefits of wider spark gaps you need to put more energy into the coil. When you put more energy into the coil you will increase 
spark duration. When you have longer spark duration you can afford to lose some by opening up the spark gaps."

He talks about the concept of stored energy being a limiting factor.  We will get to know that and use it by repeated pulsing
to get really good results.  Testing will be require.  There are so many unknowns I can't see proving it all before just starting 
on some testing.  Recently, it became clear that the testing cannot proceed without a microcontroller in the test circuit, since 
it needs a timed sequence of events to do a repeatable test.

"Modern motorcycle engines spin fast enough that even with a distributorless setup there is not enough time to fully charge the 
coils. That's why capacitive discharge ignitions are seen mostly on race cars and motorcycles. "

Here he mentions how the slow buildup of energy in a coil, and the imperfections of the coil mean it comes out slowly and so also 
limits function.  All that gets worse the higher the turns ratio, so you go with less turns and use doublers, etc, and beef up the 
wire size in the secondary, all things I am planning to study more in a few minutes.  The thing that makes a coil more imperfect 
for the costs to make one compared to capacitors is inter-winding capacitance.  It's all a trade off.

Our application does not need so big a coil , (or transformer), since it stores less energy and that gets replenished more often.

I'm on it Nathan.

John Griessen