Joule Thief

freepow · January 06, 2011, 08:18:11 AM

@ dasimpson

I have been using a 50F 2.7v supercap in my 5 yo son's night light, I only have to charge it to about 1.5v
and the 1x LED seems to last all night and by the morning it becomes very dim.

If I charge it to about 1.5v that means I will get a total of approx 10 mA, for 1 Hour or for 1 Min = 600 mA,

So for example if I lit a 20xLED (240v) bulb @ a draw current of 150 mA, I could light it for 600/150 = 4 min

A 10F charged to say 2.5v should give you about 3.4 mA for 1 Hour or 204 mA for 1 min

I think I may have come on to something, not sure yet, but my low draw joulethief has 1x AA rechareable
battery for the run battery, and I have my 50F supercap for the charge cap, and I have it running back into the AA battery, my interesting results so far is this...

When I adjusted the Var-res at just the right spot, the results were strange...

RUN BATTERY SUPER-CAP

1.229v .910v
1.239v .920v
1.241v .925v

By adjusting my var-resistor to the spot with where LED lit at the lowest light level (still bright)

results so far over a short interval of time... RUN BATTERY SUPER-CAP

1.252v .805v
1.255v .804v
1.257v .803v

Then I adjusted the Var-res to the spot where the LED lit the brightest (very bright)

results so far over a short interval of time... RUN BATTERY SUPER-CAP

1.128v .870v

But now I have found the spot where this is happening...
1.238v 1.010v
1.238v 1.040v
1.238v 1.044v
1.238v 1.052v

I can literally charge either one up by simply adjusting the Var-res or charge both up at the same time !
I may be onto something, and the LED is lit bright or super bright while I am running this joulethief and charging at the same time.

dasimpson · January 06, 2011, 10:06:42 AM

Quote from: freepow on January 06, 2011, 08:18:11 AM
@ dasimpson

I have been using a 50F 2.7v supercap in my 5 yo son's night light, I only have to charge it to about 1.5v
and the 1x LED seems to last all night and by the morning it becomes very dim.

If I charge it to about 1.5v that means I will get a total of approx 10 mA, for 1 Hour or for 1 Min = 600 mA,

So for example if I lit a 20xLED (240v) bulb @ a draw current of 150 mA, I could light it for 600/150 = 4 min

A 10F charged to say 2.5v should give you about 3.4 mA for 1 Hour or 204 mA for 1 min

I think I may have come on to something, not sure yet, but my low draw joulethief has 1x AA rechareable
battery for the run battery, and I have my 50F supercap for the charge cap, and I have it running back into the AA battery, my interesting results so far is this...

When I adjusted the Var-res at just the right spot, the results were strange...

RUN BATTERY SUPER-CAP

1.229v .910v
1.239v .920v
1.241v .925v

By adjusting my var-resistor to the spot with where LED lit at the lowest light level (still bright)

results so far over a short interval of time... RUN BATTERY SUPER-CAP

1.252v .805v
1.255v .804v
1.257v .803v

Then I adjusted the Var-res to the spot where the LED lit the brightest (very bright)

results so far over a short interval of time... RUN BATTERY SUPER-CAP

1.128v .870v

But now I have found the spot where this is happening...
1.238v 1.010v
1.238v 1.040v
1.238v 1.044v
1.238v 1.052v

I can literally charge either one up by simply adjusting the Var-res or charge both up at the same time !
I may be onto something, and the LED is lit bright or super bright while I am running this joulethief and charging at the same time.

doh maths not my strong point that lot kinda went over my head lol
searching internet now to understand the maths in the use and size of caps

dasimpson · January 06, 2011, 02:25:03 PM

ok i have a AA battery that reads 1.240 volts on the positive side of the battery a 1k resistor
i have the positive side of my multi meter after the 1k res the negitive one is on the negitive side of the battery the meter is set for 200ma
and i get a reading of 16ma what am i acturley reading here?

am i measuring current avelable?

osiris · January 06, 2011, 03:25:25 PM

Quote from: dasimpson on January 06, 2011, 02:25:03 PM
ok i have a AA battery that reads 1.240 volts on the positive side of the battery a 1k resistor
i have the positive side of my multi meter after the 1k res the negitive one is on the negitive side of the battery the meter is set for 200ma
and i get a reading of 16ma what am i acturley reading here?

am i measuring current avelable?

be carefull with your meter .. when it is configured porperly it will BLOW YOUR FUSE ..

this is why i do not read out put i have filled rooms with smoke .. its your choise tho

i have blowen many meters

i just finished my ubc charger rapid speed !

i fill 5.2vdc @1500f in less than 15 min .. burning up 1000v diodes at 1 amp

so it works well

osiris

dasimpson · January 06, 2011, 03:30:43 PM

Quote from: osiris on January 06, 2011, 03:25:25 PM
be carefull with your meter .. when it is configured porperly it will BLOW YOUR FUSE ..

this is why i do not read out put i have filled rooms with smoke .. its your choise tho

i have blowen many meters

i just finished my ubc charger rapid speed !

i fill 5.2vdc @1500f in less than 15 min .. burning up 1000v diodes at 1 amp

so it works well

osiris

i start at the 10amp reading if it is below .2amp then ill move to the 200ma range

i give up with caps after relising that 1500f and other sizes when i worked out thay are only amps per second

and the maths give me a head ack