This experimenter’s circuit uses ten BF245 JFETs in parallel to get the 30 to 40 millivolts up to LED voltage. Here’s the Youtube video. IT looks like I will have to reduce my primary winding from two turns to one turn.
Archive for January, 2013:
2013-01-20 Very Low Voltage Joule Thief Ver. 2
I removed the two core coil from the circuit of my previous blog and put the 550 turn coil in its place. In my haste to see how well it worked, I connected the power supply clip leads backwards, so positive was connected to negative, etc. But I really didn’t notice, because it was working.
(Read More…)
2013-01-19 Very Low Voltage Joule Thief J105
I wound a half inch core with 200 turns of 30 AWG enameled wire and connected it up to a J105 JFET. The JFET doesn’t require a resistor, so there’s no power wasted there. I used two turns of 20 AWG stranded insulated wire for the primary (drain) winding, so the ratio is 2 to
(Read More…)
2013-01-18 Watson’s “Wireless” Joule Thief
I was watching Sohei’s “wireless” light on Youtube and I decided to build a similar one. It’s not much different from the Tesla pancake coils I was experimenting with recently. This “wireless” Joule Thief is not really wireless, because it doesn’t really radiate radio frequency energy. It’s just a transformer with the secondary winding separate
(Read More…)
2013-01-17 Questions About Joule Thief Transistors
This is a continuation of my earlier Questions about Joule Thief.. blog. Paul, who is from the U.K., said he is using the BCY51, BFY51 and 2N1711 transistors, and wanted to know if I thought they were suitable for a Joule Thief. The information I could get online about the BCY51 was scanty, but what
(Read More…)
2013-01-16 LED Light Bulb – More Discussion (contd)
Dilemma Changing Incandescents To CFL or LED Both CFLs and LED lights can be damaged by excessive heat, which often happens and makes people wary of buying them because they often think they have purchased “Duds”. The problem is that since incandescents lived on heat, the fixtures either ignored the heat or tried to keep
(Read More…)
2013-01-15 Developing a LED Light Bulb – High Output And Efficiency
Quantsuff sent me a link to some Kickstart entrepreneurs who are developing a high efficiency, high output LED light bulb. The lights are equivalent to 75 and 100 watt incandescent lights. They have already surpassed their $20,000 goal, so they really don’t need more contributions. One big reason why I would not consider contributing is
(Read More…)
2013-01-14 Questions About The Joule Thief, Particularly The Coil
I received an email from Paul, with some good questions about the Joule Thief, particularly about the coil. He’s given me permission to use them in this blog. Here is his intro and first question: Imagine 1st an average JT circuit just as frequently made. 1 transistor, 1 white LED, 1 resistor, 1 battery at
(Read More…)
2012-01-13 LEDs Not Suitable For Lighting
I was reading the LED light bulb project that Belza built. Most of this was written in Czech, so you may want to run it through google translate. He builds a 240 lumen LED light using a regular screw in plug from the end of a light. At the end he confirmed what I have
(Read More…)
2012-01-12 FM Microphone- Everything You Wanted To Know And Then Some
I built up this FM microphone from belza.cz. The circuit is super simple, uses only a single transistor. The output of the electret condenser microphone is coupled directly to the base of the RF oscillator, and causes the frequency modulation. However since the microphone has no amplification, it is not sensitive and the user must
(Read More…)
