Joule Thief

[resonanceman]

PS  The modified Fuji will put out over 350 volts so if you run that into a low voltage supercap, most are 2.7 or 5.5 volts, it will blow up.  Be careful.

Bill.


This  would be true  if the spikes were big enough.

With a small battery powered  JT I don't think that there is any real risk other than  the possibility of damaging the Ucap by overcharging it.
Gadget  said a while back  that the  screw on the  - side popps out  if the pressure gets to high inside it.

I tried charging  my Ucap with half a dozen  different JTs   
I can charge them.........but not  as fast as I  would like.


gary

Edit
A couple of the JTs  that I tried  were over 350 V

[Pirate88179]

Gary:

Are you saying that you can try to charge a 2.7 volt b-cap (or supercap) with 350 volts or more?  As long as you monitor the cap's charge and don't go above the rated 2.7 volts? (Overfill it)

I have never tried this myself so I have no idea.  I just thought (assumed) it was way too many volts.  But, is it because we have not a lot of power on the output?

If this is true, then I have some things I have always wanted to try but did not want to destroy my caps.

Bill

[resonanceman]

Gary:

Are you saying that you can try to charge a 2.7 volt b-cap (or supercap) with 350 volts or more?  As long as you monitor the cap's charge and don't go above the rated 2.7 volts? (Overfill it)

Bill

Exactly

we are working with impulses here  so some things  are a little different.

A meter on the cap reads rock solid DC 

Like  you  said.........just don't  overcharge them.


I know  you already know this.........so for others .........do not assume that   you can limit  the voltage  it will charge to by keeping the  voltage you read coming out of the JT low ........volt meters do not read the spikes .......and the spikes are what is doing most of the charging.

I am currently charging a 12 V battery with  a JT.
The voltage across my bridge is 6.1V AC
The battery voltage is  12.08 and climbing  slowly

gary

[guruji]

Hi guys I cannot understand that when I try certain circuits that they claim certain low consumption in their circuit on my side I cannot find one All circuits that I tried are not what they claimed.
Hope someone give me explanation.
Thanks

[xee2]

@ guruji

Hi guys I cannot understand that when I try certain circuits that they claim certain low consumption in their circuit on my side I cannot find one All circuits that I tried are not what they claimed.
Hope someone give me explanation.
Thanks

I made the following replication of kooler's circuit and it worked for me. I think the meters may not read the pulsed current accurately. So meter may read several times more current but that is still very low. The current must be low to have it run on just the capacitor.