Joule Thief

[dasimpson]

yeah i have had problems with this also my jt draws 12mah with a meter in sereis between the jt + mand battery
the battery i use is 2500 ideal worl i should get over 200hours but that would take the battery to 0 volts to get the full 2500
but i find that a fully charged battery at that current draw seems to last 10 hours or so

[dasimpson]

to run a pusle motor i think the faster you can charge the cap and the highest farad cap you can find be best as this will give a large pulse of power to the coil but you need it to charge very fast ready for the next magnet arriving

Hi dasimpson
Ok Great. I don't need to know exact just a ball park figure. So what you gave me is perfect. I am in the process of adapting my JT to run a small pulse motor I am working on.
thanks
Bizzy

[dasimpson]

ok the spec of my unit is
5k resistor
2n3904
1 inch toriod black
cat 5 cable
winding are 11 collector 11 base
1 led diode and cap on output to measure voltage
current draw 18ma
battery is 2500mah
going to connect it now and will post when that light stop so we can see how long it has lasted
battery start voltage 1.26v

[Bizzy]

dasimpson
a 5k resistor is much bigger than the 1k which most were using originally. Have you tried a 1k before? and if so doo you see a differance in performance?
thanks
Bizzy

[dasimpson]

i normaly use 1k i just ran out i guess i could put a few 5k in parallel to get 1k but with the 5k i must admit the ampage draw is a lot lower and the light is still good not enoth to light a room but well enogth to be able to see round the room maybe one in each corner might give ethern more light but as a bedside light dose very well i have another unit i use as a tourch so i use that for direct light btw that a 4x4 metre room i just tried with another jt and as i droped the resistence the light got brighter but also the current draw went up
as it stands at the moment i get 30v output i could use 10 leds in series and the draw of the circuit wont be affected as far as i know