Joule thief triggered with radiant, input current reduce with load

[sucahyo]

This is my attempt to combine idea of:
- radiant triggered transistor
- work on any voltage

The video:
YouTube - Joule thief triggered with radiant secondary

The result:
- input current will reduce on load.
- potentiometer can be used to tune the circuit
- the circuit do not work with switching power supply as source, a very big drawback for me.
Edit: It's working now, don't know what cause previous problem.
- more efficient than my pnp npn 555 circuit. Previous has 0.7A at 10.5V input with 0.4A at 2.7V output, this can be tuned to 0.12A at 9V input with 0.12A at 2.7V output (input voltage is an estimation).
- need bypass switch to start
- inversing secondary leg may increase or reduce output voltage. Always try with coil without common terminal (no car coil / flyback transformer), but you are free to try.
- using 15K base resistance, 12V source battery , 2.8V charged battery, output current is 100mA. Circuit will not work without load, will not work if amp meter is used to measure input current. The input current should be around 100mA based from initial experiment.
- charge two 1000mAh nicad in series in one half hour with 100mA output current. charge is real, light up 3V bulb more than an hour.

[Lidmotor]

Replication

I replicated this circuit today using a 12v / 117v transformer. I didn't have the transistor that you used so I just used a 2N2222 NPN and a 2N3906 PNP. It worked!! It is a very interesting Joule Thief circuit to play with. I ended up just running it on AAs because the poor little transistors got pretty hot at higher voltages. I did run it for a time on a solar cell phone charger (5.5v) and could keep it running while the charger was plugged into the wall outlet transformer at the same time. I used a 25 ohm rheostat ( high amp wire wound resistor) to control the power going into the circuit. For the diode I used a little 1N914 and then switched over to just a white LED. This is a fun circuit and there is much of potential here.
Thanks for presenting it here.

Lidmotor

[sucahyo]

If higher voltage make the transistor got hot, I use higher resistor value at PNP base. What resistor value that you used?

I use resistor value which close to the non operating limit, little higher and it won't work. Removing the load will shut it off too. At around 8K ohm, 12V input, the output current is about 100mA charging almost full two nicad in series.

If you increase the resistor value at PNP base, you wouldn't have to use rheostat.


I found this circuit charge Zinc Carbon better than my other circuit. I got success charging D-Size Dry cell the other day, raising detected amp from 0.35A to 3.3A in one half hour. Will try to do it again today with another D size Dry cell and 9V zinc carbon.

[redeagle]

interesting circuit you have here. Just studying the circuit diagram, it looks like when the pnp fires there would be a temporary short in the circuit of the primary battery. have you thought about trying to power a load betweeen the collector of the pnp and the base of the npn to utilize that power or use resistance there to at least limit the current to the base of the npn. This same issue plagues the full sequential bipolar circuit that is used in the bedini window motors.

[sucahyo]

interesting circuit you have here. Just studying the circuit diagram, it looks like when the pnp fires there would be a temporary short in the circuit of the primary battery. have you thought about trying to power a load betweeen the collector of the pnp and the base of the npn to utilize that power or use resistance there to at least limit the current to the base of the npn. This same issue plagues the full sequential bipolar circuit that is used in the bedini window motors.

Is it really necessary?

Since the output of the PNP can be limited with resistor, it will also automatically limit the output of the NPN if we use high resistor value for the PNP. My current circuit draw 150mA charging two nicad using around 8K ohm PNP resistor. I can not go lower since it would shut off the oscillation.

Edit, exact number is : 140mA at 9.8V input, 90mA at 3.08V output when charging two "AA" alkaline battery. Coil will draw 1 amp if transistor is by passed.

I found that using two transistor this way is more efficient. This circuit is at least 4 times more efficient than 555 driven 3055, twice more than 555 driven 2955 driven 3055.


BTW, I found that I can light up neon brightly if I poke it a couple of time using 12V input:
YouTube - Joule thief can light up neon or charge battery but not both.

Neon dies if I put battery though.

[redeagle]

I guess I should rephrase my question. Since the npn is switched at a loss from the input source, how much of the current draw is being used to switch the npn transistor? Knowing this will give me more of an idea on the efficiency of the coil at converting primary current to charge current.

[sucahyo]

I try to measure current from source positive to PNP collector, at 10A setting in the amp meter, it read as zero. My other amp meter setting broke unfortunately so I can not measure it using lower range. During this test, PNP base resistor is around 8K ohm, input current 0.13A using 12V battery, output current 0.09A charging two zinc carbon. I hope this answer your question.

Edit: using analog meter the current going to PNP collector is about 4mA.


I am thinking that if I use 110V to trigger the PNP, it would require less current and it would also trigger faster. By using this to trigger the NPN, I would get faster switching.

[sucahyo]

Confirmed reduced input on load.

Just doing another test to make sure the the reduced input current when load is added is not a fluke.

Input current without load is 340mA.
Input current with 3V light bulb as load is 270mA.
Input current with the diode output shorted to source positive is 200mA.

I guess I reach another goal of mine with this circuit. A circuit that will reduce input current on load. The other realized goal are:
- cold electricity, circuit that charge battery without heating them.
- harmless electricity, circuit that do not shock people but light up CFL very bright. Not with this circuit though.

Edit:
The video still in processing mode after a while, I hope this video doesn't make my youtube acount banned. Will change the video title for safety reason.

I decide to delete the old one and reupload it again with different caption. This time it was quick.

YouTube - Input relation with load

[sucahyo]

Doing another replication which turn out to be more efficient. Using 9V/240V 2Amp transformer, same circuit with different NPN, with 60mA at 12V input can charge 2.9V at 80mA. While with 250mA at 10.5V input can charge 12V at 65mA. This much much more efficient compare to previous circuit where to charge 12V at 65mA may require more than 1 Amp.

YouTube - More effcient hv triggered joule thief with transformer with core

[sucahyo]

huge input drop when shorted

Input is computer power supply at 10.5V, input current:
Without load = 0.56A
With 12V battery as load = 0.22A, battery charged at 0.065A
Output diode connected to source positive = 0.01A

Input current reduce if the output is shorted.
YouTube - input current measurement of soft iron core version of hv triggered JT

The circuit now work on any power source. Computer power source or switching power source work now, even 1.5volt battery.

[sucahyo]

not overunity device

Just trying to charge two battery in parallel. I thought the input current will drop just like when charging nicad, but it didn't. Input and output current stays the same, although I seeing voltage increase in the second charged battery. I will try to add more battery and see what happen.

Edit: Adding third and still nothing happen.
Each battery have their own BC1040CT diode.

parallel charging reduce the charge on each battery, while in series will increase input current and reduce output current.

YouTube - charging battery in parallel will reduce the charging share

[sucahyo]

Battery do not get charged with low input current

I found out that output current is not the correct indication of charge. I currently charging my nicad with 80mA output from 60mA input. The rate of charging is about 5 times slower than when using 250mA input and 150mA output.

I think output current should never be use as charge indicator, it should be the input current.

[CosmicFarmer]

This thread is brilliant and I think more people should see your videos. I dont have your PNP otherwise I could make it... I'll look around

[sucahyo]

This thread is brilliant and I think more people should see your videos. I dont have your PNP otherwise I could make it... I'll look around

Thanks . I have to buy 3055 and 2955 in pair so having a circuit that use both is a good thing for me. If available MJ21193 & MJ21194 is better than TIP3055 & TIP2955.