Quantum Energy Generator (QEG) Open Sourced (by HopeGirl)

[Farmhand]

OK no probs, I'm ordering some tomorrow anyway, just curious, those are measuring 0.1 Ohms. I can look with the scope and
see if there is a difference between the power resistors I was using and these from the killaWatt meters.

It's not the price of the resistors Mark it's the postage, I'll have to spend an hour tonight listing all the other parts I want as well.

Now will a Lux meter tell me if a lamp is giving off more light ? Or will it only tell me the brightness, not the amount ? I'll probably
just make one of TK's light meters. I'll need parts for that.

..

[MarkE]

OK no probs, I'm ordering some tomorrow anyway, just curious, those are measuring 0.1 Ohms. I can look with the scope and
see if there is a difference between the power resistors I was using and these from the killaWatt meters.

It's not the price of the resistors Mark it's the postage, I'll have to spend an hour tonight listing all the other parts I want as well.

Now will a Lux meter tell me if a lamp is giving off more light ? Or will it only tell me the brightness, not the amount ? I'll probably
just make one of TK's light meters. I'll need parts for that.

..

Small packages from Digikey cost about $11.00 postage if sent by US Priority mail to anywhere in the USA.  The cheapest FedEx and UPS options are about $21.00.

LUX meters report intensity in LUX.  To get total light, you have to measure in all directions around the source and integrate.  The $10. digital photometers on eBay aren't bad.

[Farmhand]

I'm in Australia, it cost me over 30 Dollars last order. But it's ok I'll get some stuff.
Thanks.


P.S. Mark can you please check back here for questions while you can, about components ?

What would be the best mosfets and mosfet driver chips to use for switching up to 24 volts in a setup like this at 840 khz or
1 Mhz tops ?
I ask because the TC 4420 gets hot driving a mosfet at 1 mHz and the power consumption for the switching alone seems
very high. At 840 kHz the driver chip is not too bad but at 1200 kHz it gets quite warm "touchy". I'm using an IRF740 but
the only others I have is one IRF540 some IRF840's And some lower voltage IRF1010's.
I've got some Si7478DP-T1-E3 mosfets but they're only 60 Volt parts. Just wondering if you had a suggestion, maybe some
new line of part or something interesting.

Digikey's postage is very fast so holding back won't hurt. I'll order tomorrow after midday.

2) Capacitors for the primary what are the very best capacitors I could use for the primary capacitance ? I'll need them to take
similar voltages to the mosfets I guess. That's an important one the ones I'm using now do get a bit warm.

..

[MarkE]

I'm in Australia, it cost me over 30 Dollars last order. But it's ok I'll get some stuff.
Thanks.


P.S. Mark can you please check back here for questions while you can, about components ?

What would be the best mosfets and mosfet driver chips to use for switching up to 24 volts in a setup like this at 840 khz or
1 Mhz tops ?

That really depends on the load.  You want the lowest gate charge that you can find that will still yield an acceptable on state resistance.  I would get a good feel for the maximum voltage with transients and then start searching MOSFETs from the voltage and up for the lowest total gate charge at the gate drive voltage of interest.  The gate charge is what is making your drivers hot. Slow rise and fall times that result from the charge and perhaps layout issues is what is making your MOSFETs hot.  At 1MHz and above hard switching losses can be quite a problem.  Resonant and quasi-resonant topologies are more complicated, but those that switch at zero voltage really cut down on the switching losses.

I ask because the TC 4420 gets hot driving a mosfet at 1 mHz and the power consumption for the switching alone seems
very high. At 840 kHz the driver chip is not too bad but at 1200 kHz it gets quite warm "touchy". I'm using an IRF740 but
the only others I have is one IRF540 some IRF840's And some lower voltage IRF1010's.
I've got some Si7478DP-T1-E3 mosfets but they're only 60 Volt parts. Just wondering if you had a suggestion, maybe some
new line of part or something interesting.

Digikey's postage is very fast so holding back won't hurt. I'll order tomorrow after midday.

2) Capacitors for the primary what are the very best capacitors I could use for the primary capacitance ? I'll need them to take
similar voltages to the mosfets I guess. That's an important one the ones I'm using now do get a bit warm.

..

[Farmhand]

My IRF740 mosfet doesn't get hot, there's only 1 amp or a bit more max so far but I run it for a long time at 0.5 amp and it stays
only just above ambient, only the mosfet driver got very warm when I was running this circuit at over 1 mHz on a previous occasion.

I would think I could get better mosfets to take about 200 volts or so than IRF740's, with only 12 or so volts input the drain only
sees about 45 volts max no spikes that I've seen. Loading the secondary just causes more current, the wave shape stays almost
the same. 100 volt mosfets would be enough for just 12 volts input but I want to be able to use 24v I guess I should just keep
using the IRF740. It's working well enough. Was thinking of lower resistance. The coils have very low resistance and so high Q
if I use too high a resitance value for the CSR the Q will drop more, I guess with loads that won't be an issue at all. I need a decent size trace without going to 50 and 20 mV per division and still have a small trace.

Here's a better scope shot of the fluro wave forms.