It turns out that theres a strong similarity between the joule thief circuit and some motor circuits. The joule thief circuit is not very efficient, although it probably will allow you to run longer, because the batteries will still provide enough power for it, even after they fall below 1 vcell. The circuit is a constantcurrent source, the value of r3 sets the current. Of course this would mean the battery getting drained pretty much earlier than a 5mm led, but its still economical than using a two 1.
The joule thief circuit uses a programmable boost converter ic. Originally posted by wquiles with the much smaller surface mount 4uh inductors i am now using i am getting about 5060ma at 1. I am in the process of building a battery charger this week and will put data about this project as i charge batteries. A highpower joule thief type circuit to drive a 1watt led from a 1. So, we can add to that circuit the simple joule thief voltage booster to get a good design for a solar garden light. The simple joule thief oscillator part of the circuit can be assembled first with the usual led to provide reassurance that the oscillator is running. Normally, if you want to light up a blue or white led you need to provide it with 3 3. Using the findings from my previous post joule thief measurements. This circuit used in this project is a modified joule thief.
One of the coils is a larger toroid with 10 turns on it, the other one is a smaller one with six turns. Bird603568 sent in this sweet little led hack thatll drive a white led from just 1. Once you have understood the circuit you can calculate the current rating required for your led and build it on a breadboard to test it. A common 5 mm highefficiency white led d1 is the key component in this design. Contents hide 1 small 1 watt smps led driver 2 introduction 3 main features circuit diagram circuit operation 4 using transformerless capacitive power supply 5 circuit in this article we understand the contruction technique of a 1 watt to 12 watt smps led driver circuit suiting to all of new hobbyists. Apr 29, 2016 here is the demo how joule thief works to light an 12 volt led this is by far the best of this circuit. The second winding has been replaced by a pnp 2n3906 and c1. Mar 21, 2015 this joule thief led or high efficiency led with 1. The concept it to try to determine a running current by using the inductor, diode and load, at the same time the switch fills up the missing load energy on a single cycle. Jul 14, 20 blinking flasher joule joule thief led thief 1 watt joule thief public. Fuji circuit joule thief led light 1 alternate energy. Here i present to you a single aa battery led circuit. I breadboarded a version of the joule thief, a simple circuit which.
There is an onboard potentiometer which can vary the output current of the driver from 0ma to 350ma. Below is a schematic diagram of a joule thief circuit. Dec 25, 2017 i stuck with the bc81725tp npn transistor used in the original multi led joule thief and the joule thief candle since it works and i purchased enough of the them to make hundreds of units. The joule thief kit can also run customer supplied leds with vfwd voltages up to 4. The boost converter is advertised as a 350ma led driver, although its really just a simple boost controller ic without an external voltage feedback input. You can use a fresh aa battery, but the circuit is special in that it accepts empty batteries. Nov 25, 2016 here a simple 1 watt led driver circuit based on a modified joule thief design, runs on a 1. My circuit looks like as shown below after i built it on a breadboard. This is a very interesting circuit, it will drive 3.
How to make led lamp 220v 50hz input circuit by using 1. A 1 watt led is relatively huge when compared to a 1. It is rated at 800 lumens and is the best led bulb i have tested to date. Ive made a joule thief, and it works fairly well, but not as well as i would like. Naturally, youd want to give this a tough, weatherproof enclosure if it were going to be run outside. Led current is set by r3, it is approximately equal to. It takes a steady low voltage signal and converts it into a series of high frequency pulses at a higher voltage. A solarcharged battery with a dark detector that drives a joule thief to run a white output led. This circuit is pretty efficient and it can power a 1 watt white led quite brightly.
Its a little wisp of a circuit that allows you to drive a blue or white led from a low voltage. The circuit can utilize an input voltage down to about 0. A little further online research revealed a neat little circuit that can power a red led using a aa battery, even a dead one. Jan 10, 2018 1w, 4w, 6w, 10w, 12w led driver circuit smps last updated on january 10, 2018 by admin 40 comments right here we research a very easy 120v220v smps led driver circuit that can be used for driving high watt leds rated any place between 1 watt to 12 watts instantly from any domestic ac mains outlet. Mar 01, 20 1 watt led driver using a joule thief circuit a joule thief circuit is pretty popular with all electronic hobbyists, because the concept allows us to operate even the white and the blue leds from a 1. Another advantage of it is that it saves a lot of battery power. I got the concept of this circuit few years back from a led torch, which was powered by a single aa battery. The good thing of this led lamp circuit is that it is not using any transformer. The circuit is obviously based on boost driver technology, other wise driving such a huge load w such minimal source is beyond imagination.
Here a simple 1 watt led driver circuit based on a modified joule thief design, runs on a 1. A suitable driver transistor, like the 2sd965, 2sc2500, 2sc2655 must be used. Is the joule thief my only option if i must use these led s and batteries. I chose 82 ohm resistors, so the total current for the three leds was 60 milliamps. Here is how a basic joule thief works, step by step. When run through the joule thief circuit, the voltage is as high as 24 volts, as shown in the oscilloscope output n the photo on the right. Simple solar circuits evil mad scientist laboratories.
So a bit of research and testing showed a simple red light could be made from a 9volt battery feeding a red led with a 470ohm 1 4 watt resistor in series. Such as we use 1 transistor and all other parts of 5 pcs only. The circuit is very simple and contains very few parts. Some notes about using the joule thief to charge nimh batteries.
Im hoping increasing the voltage from the jt will improve it, but im not sure how to increase the duty cycle of the transistor. For the joule thief with the same led current, the supply current was 76. The niftystuff led boost circuit joule thief is a device designed for two purposes 1 to suck any and all traces of juice from your dead batteries. Actually, i own very few lights well, to a nonflashaholic i own an arsenal but in reality i only own a few lights most are customer lights that i photograph before sending them out to their respective owners. The bridge rectifiers are used here because we have to convert ac to dc because leds can only run from dc volts. I think to make led lamp circuit by using 1 watt leds 300ma and 3. Out of boredom i got interested into the joule thief circuit. Simple 1 watt led driver circuit making easy circuits. In the 5th design lets learn how to illuminate a 1 watt led using a 1. Oct, 20 i added four more led lights wired in parallel and tried to power the circuit using four aa nimh rechargeable batteries wired in series but the batteries dont provide enough voltage. Yesterday i built two of them using a 2n3904 transistor, 1k resistor, 10mm warm white led and two different handwound coils. Jan 10, 2018 the simple 1 watt led driver circuit buck converter presents approximately 90% efficiency. I am trying to compare using the 2 aaa batteries at about 2. Red light for illumination the joulethief atm, optics.
A joule thief is a selfoscillating voltage booster. The simple 1 watt led driver circuit buck converter presents approximately 90% efficiency. The extreme joule thief kit utilize a dedicated onboard 1w led driver which can operate from voltages as low as 0. Mar 10, 2012 a highpower joule thief type circuit to drive a 1watt led from a 1. This circuit is a variant of the joule thief in that it contains 2 transistors and a simple standard 2 lead inductor instead of a hand wound 2 wire inductor you can use it as a white led torch.
This joule thief led or high efficiency led with 1. Base resistor i changed the base resistor value from 1k to 6. Not only does it work with a brand new battery, but it works. The coil consists of a standard ferrite toroid core with two windings of 20 turns each using 0.
Technical specification of the highefficiency led used is shown below. So a bit of research and testing showed a simple red light could be made from a 9volt battery feeding a red led with a 470ohm 14watt resistor in series. The concept discussed here remains exactly identical to the usual joule thief configuration, we just replace the normally used 5mm led with a 1 watt led. The circuit consists of a pair of coils wound on a ferrite. This circuit is a variant of the joule thief in that it contains 2 transistors and a simple standard 2 lead inductor instead of a hand wound 2 wire inductor.
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