Joule Thief

[dasimpson]

well with just a diode on the + side of the secondory i get 40 or 50 volt dc about double that ac reading
but it fills the cap to the 40 or 50 also but slower not instent
but i gues it would be instent with no load

[dasimpson]

this is strange im getting 190vdc and well the ac voltage is off the scale i mean litraly it is zeroing out dmm

[The Observer]

Greetings,

I created a Penny Pill Jar Battery (with Bolt).
1 Jar gives an approximate voltage of .650 Volts.

Two of of them in series run a JT just fine !

Will be interesting to see how long it will last.
The Picture Below should explain.

The Observer

[Pirate88179]

Observer:

Nice idea!  By using just tap water, my guess is they should last quite a while.  We will see.  Good job.

Bill

[crowclaw]

this is strange im getting 190vdc and well the ac voltage is off the scale i mean litraly it is zeroing out dmm.
The problem with digital multimeters is their inability to give any kind of true reading when checking these pulsed waveforms, and in some cases you can easily destroy them!! If the output was steady state DC then then a measurement can be taken. The JT waveforms are pulses which can be of a complex nature, rich in harmonics; the ideal instrument of course is an oscilloscope. If you are unsure of the output voltage amplitude you can put together a simple attenuator network by consisting of say three or four high value resistors connected in series, either 20K or 100K (keep the values the same) connect one end of the string to common ground -ve and the other end to you output. The output value will be divided down,  using 4 x 100k the last in the chain connected to ground will share 1/4 of the output. At least this way you prevent overloading your test instruments. The load on the circuit using the values suggested is insignificant. M