In this Youtube video comment, he asks the question [A] Joule Thief is a concept or it defines a device that uses a toroid? About your Q: The original Joule Thief was a simple one transistor device that used the inductive kick or Counter EMF of a coil to boost a low voltage up
(Read More…)
This is a reply to Paul’s question. After all the experimenting you have done since this was first designed, do you still favour a SJT over a conventional JT routinely, or can the extra components be circumvented by a different coil design or optimised transistor specification. The SJT has the feedback winding connected to the
(Read More…)
At Xmas, I had more than a dozen of the Blue Blinkies under the eaves. Last year a guy at work gave me a bag full of used AA cells, more than 5 pounds, must’ve been well over a hundred. Some measured 1.3V, some measured less than a volt, and some leaked juice and I
(Read More…)
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.
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…)
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…)
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…)
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…)
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…)
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…)
