Joule Thief

[electricme]

@Xee2

On the below circuit, there may be a tendency for one of your transistors to get warmer than the other if they are not identical, eg if from a different batch, one of them might have thermal problems, the hotter transistor will be caused because it is taking more of the current/load.

If you place a 1 ohm 5 watt resistor in series on each Collector or Emitter, then the load will be  more equally shared.

jim

[nievesoliveras]

...
The  schematic would  be  exactly like your  Improvement 1    except   that   I  used what  I had on hand ....  the transistor  is 3055   the  base resistor is a 100K pot
The  cap  is  1uF   
I  guess the biggest  difference is   that  I  used my LM  coil .   It  has   an 8 turn  bifilar  primary   and  a 300 ft  secondary ( one  spool of  red Radio  Shack  mag  wire) #30

This  is not  quite  self charging  at least not at the   brightness  shown
It  MAY be self charging  if the  power is turned all the way down
...
gary

Thank you @resonanceman for the explanation !

Jesus

[xee2]

@ electricme

If you place a 1 ohm 5 watt resistor in series on each Collector or Emitter, then the load will be  more equally shared.

Thanks. The separate base resistors should force equal power, with slight variation due to gain differences. Adding collector resistor would defeat purpose of paralleling transistors.

[xee2]

@ all

Note, any voltages I measured across a 15M resistor are wrong. This was a voltage divider and I had not used the correct resistor values.

[stprue]

@gary

If you use firefox go get the add on called downloadhelper, that way you can download you tube for watching directly on your pc.


@all

just a reminder of the beast 16x140v output !

WOW so this things total ouput would be 2240 rectified DC volts!  Great work MK1 and nice clear pic as well