Joule Thief very very low input 0,136 volt

Joule Thief very very low input  0,136 volt

This Joule Thief work at a very very low input voltage from 0.125 to 0.35 volts and the output voltage is 2.7 volts, to the LED. An ordinary Joule Thief work…

24 replies on “Joule Thief very very low input 0,136 volt”

@marchall & fixerden: sorry, I forgot to say that between collector pin and (+) pole of measuring lead of DMM, we need to put a resistor abour 1kiloOhm. In ordert not to disturb the voltage spikes that live in the collector pin. Beacuse the voltage spikes needed in every JT circuits to make LEDs glowing. Thank you.

Or just plugin a capacitor to JT and measure voltage from it (maybe it’ll be better to plug capacitor in parallel with voltmeter).

Instead of buying super-duper extra expensive oscilloscopes and other precise stuff — the smarter way to measure JT voltage is to plug a capacitor instead LED and then measure it’s voltage. Capacitor should be about 10-100uF and 16—50V (for small JT) or 250V and upper for larger ones (be very careful to prevent electric shock from it!). Enjoy! )))

@marshall: Good question. I assume you use the DMM or Analog Multimeter, both you haved read shows only AVERAGE VOLTAGES. In fact, in JT circuits, LED lite up by pulsed voltage that have peak value about twice or more compared to the average voltage. You can see the real voltage applied at the LED by watch the waveform through an oscilloscope (the best tool), or read the peak voltage through a special purpose PEAK VOLTAGE VOLTMETER (cheaper tool).

hello another question,,I have a working JT,,but when I’m measuring the CE voltage (using DMM) with or without LED, I can only measure above 0.8V..I know my JT is working because it can light up my LED with source voltage of above 1.1V.. how can I measure the output voltage correctly..

I want to use it for my peltier device,,what if my voltage fluctuates from 0.3V upto 0.6 volts,so obviously it will stop working..
how can I make it run from 0.3V up to higher than 0.6V?

what is the effect of having different number of turns for the core,,and which is better to use

For my posted video 45mv Joule Thief circuit i’m using Japanese NPN transistor “2SD1450”.Do check out.The key to get circuit working at lower voltage is low vce(datasheet) 0.13v for my selected transistor.
The toroid core used by Larskro is defentely better since it’s smaller and led’s brighter than mine which likely is a iron powder(blue toroid).

The transistor is BC107 or Bc547 or better 2SD1450.
The converter works fine with a 60 watt peltier element.

Your current circuit might improved a little more if you reduce the turns from 10T to 6 or 5
to be powered from peltier.My observation base on those various dedicated power harvesting module for peltier or very low generating device like vibration.All of the variant(around 5) i seen mainly seems to have same turns with tiny toroid(100:1).The lowest ver is 20mV powered by peltier.To be mounted side of big fish for tracking purpose on interval basis.
But those device i seen are low power version.

I have replicated your circuit and improved it further by using better transistor as the key component.Current the joule thief could be powered as low as 45mV for led to be seen lit and stops working at 43mV.
Thanks for sharing your design idea.

@larsko: but anyway, I found in your schematic diagram that you forgotten to draw the blue LED, That should be connected between BC107’s base (anode) and BC107’s collector (Kathode). Tell me if i am wrong Thanks again.

Use a diode or two as well. Battery with 1v+ silicon diode = 0.3v.

Having a few shotkey and germanium diodes can be handy.

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