Joule Thief

[Mk1]

@all

I have been replicating the mk1 high voltage, on other toroid , now i am really confused , my meter show below 200 v then it goes over , i change the setting to 1000v now its showing me 800 v, but if i go back to the 200 v setting it show under 200v
so i get readings in both ranges , my meter is not helping much on this , i scope would be better .
But my new toroid are good but strange readings .

Mark

[Artic_Knight]

the picture i post here has the battery and probe info i was hoping for. what i wanted to see is the frequency, wave, and voltage information for the pure oscilation version of this curcuit.  the cap is included to supposedly increase the frequency and the resistor is removed to see how the curcuit would like to perform with no restrictions.  its been years since i had access to a osciliscope and dont recall how to properly probe (plus dont have access to one yet  ) but im interested in the output of the "oscilating curcuit" itself as this should be.

my objective is to find the simplest purest and best performing oscilator then from there build up on it to power what ever be the case and hopefully being mindful of these objectives come to a better version of the joule thief

thanks

[Thaelin]

Hi all:
   Just wanted to share my last bit of fun. I made a jt out of a large metal washer. It worked ok
but what was funny was the scope output wave. It has two distinct waves with one superimposed
over the other one. Like haveing the on and off pulses of the transistor riding on an AC signal. Very
strange. Funny to see it. Other than that, nothing to boast about for output wise.

thaelin

[hazens1]

@MK1
Thanks for the info about dead spots. I'm beginning to think a DMM alone is useless for testing the output of these high voltage JT. I get weird reading as well. Like when I add a cap to the output the measured voltage goes up anywhere from 10%-100% depending on the circuit used.

@All
Soon, I'm going to send a JT into the air at night on an Electric RC Airplane I'm building. I want to add lots of lights, so a high voltage JT circuit will be perfect and won't drain my main engine battery since I'll use a seperate battery for the JT. I've got the fuselage finished. I just need to add the LEDs, JT, Servos, Motor, Speed Control, Reciever and Batteries. Wow, I've got a lot of work to do 

[TheNOP]

I have been replicating the mk1 high voltage, on other toroid , now i am really confused , my meter show below 200 v then it goes over , i change the setting to 1000v now its showing me 800 v, but if i go back to the 200 v setting it show under 200v
so i get readings in both ranges , my meter is not helping much on this , i scope would be better .
But my new toroid are good but strange readings .

i suspect that the resistance of your voltmeter is changing the impedance of the coil enough to change the frequency.
the resistance is lower on a 200v range then on the 1000v range.



@Artic_Knight
i can't make your circuit to start oscilating.
are you getting anything else then the battery's voltage ?