Mosfet Capacitor Dump Experiments

[SkyWatcher123]

Hi all, been working on some oscillators and was thinking about trying the capacitor dump method again and a member on the forum inspired me to experiment some more.
Testing different capacity capacitors, to see which gives the best charging and least input and keeping a watch for any extra charging effects.
Also think the partnered output coil tech. could be useful here, as the more the output is loaded with that tech., the input power decreases, that would be something to test later on.
At the moment, i am using a pancake coil, speaker wire joule/meissner type oscillator, to charge the dump capacitor and a 555 timer and mosfet to dump the capacitor.
So far, the best charging, seems to happening with larger value capacitors, though it is said, that a low uF cap can work well, if the right kind of sharp capacitor dump and frequency is created.
Tried 5600uF-70volt low esr capacitor and now testing a 1.5 farad car audio cap i had laying around.
The car audio capacitor is charging the heck out of the 12volt 5ah sla battery at around 3hz pulse dump frequency.
Will continue to share further experiments.
All comments welcome.
peace love light 

[erfandl]

Hi Skywatcher, nice to see you working on this project.
A few years ago I designed a cap dump circuit with a microcontroller (AVR) and got decent results. Using the Joule Thief circuit, I charged a 470 microfarad 35V capacitor, then the microcontroller as a capacitor dump gate activated the MOSFET base when the 35V capacitor was charged and discharged the energy stored in the capacitor into a battery. Now I want to redesign the same circuit without using a microcontroller. I think that using the thyristor, which was already mentioned by the user joellagace, will give better results. I waiting for your test result.
Good luck. 

[joellagace]

The problem with using a SCR if you want to call it a problem  is this cap dump is somewhat limited in speed, you can hear the clicks it makes of a few per second in my videos. If your high voltage backEMF source gets "too" hot the SCR simply does not go back into an "off" mode and you get no on off dumps.

On the bright side, SCR seems to offer the best to save power, my back emf generator with cap dump takes around 60ma of current to operate in this mode.

Always looking for new methods, I'm kind of broke right now. I got to wait about a month before I make a new order, Somethings to order are some higher voltage SDRs and loads of them this time! And more of those little square wave generators, they seem to only need milliwatts to operate. And some MOSFETS to experiment with new switching circuits. NEONS and ZENER diodes of various values.

Looking forward to those spring experiments!

take care.

[ramset]

Joel
Do you have a PayPal you can link to ?
Or some way to get funds ?( would Amazon gift card work ?)


Not good to have such a dedicated open source builder sidelined
Do to need for parts
Respectfully
Chet K

[joellagace]

With inflation no one has any money these days its not just me. I got a bunch of stuff for sale like ham transmitters and such on ebay right now and nothing these days is making fast sales, People here in north America are making the decision if they can have eggs for breakfast or not. And that is regular people. It is the worst time to ask for money. I did have setup some pages like gofundme in the past. Nothing of that really worked and I don't like asking people for money.

But yeah the paypal thing is an idea, I tried it in the past as well. Like on my facebook and twitter and such.