Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [joule-thief]

voltage boosting circuit.

A joule thief is a minimalist self-oscillating voltage booster that is small, low-cost, and easy to build, typically used for driving small loads. This circuit is also known by other names such as blocking oscillator, joule ringer, vampire torch.

In short, joule thief is voltage boosting circuit.

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Is this video fake? I thought Tesla coils only worked on AC

This video shows a 9-volt battery connected to a wire as a primary. The first reason I think this is fake is that he is powering a Tesla coil with 10 volts. The second reason is that Tesla coils work on AC, or at least I thought so, and he wouldn't…
Gabriel ashmore
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Why can't I light a LED with a 1.5 V battery?

The LED I am using requires a higher voltage to light than I have supplied, and as a result, it doesn't light at all. I would expect at least a dim light, but light is not generated. Why this behavior of "if there isn't the required voltage level…
Diego Alves
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Least expensive way to boost DC voltage

What would be the least expensive way to boost a DC voltage? The aim is to convert 1.2 V/1.5 V (from an AA/AAA cell) to 3.3 V to power a small 8-bit microprocessor, like Atmel ATtiny45 or ATtiny2313, and also (if possible) 6 V to power a…
bdutta74
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Regulated Joule Thief: why it works?

Please explain to me why this circuit can give me a regulated 5 V? I understand the Joule Thief part, but why the regulator part work? simulate this circuit – Schematic created using CircuitLab Especially, why the Zener diode D2 is crucial at…
Maxthon Chan
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Is there any benefit to using a voltage booster (such as Batteriser) on "dead" batteries?

The Batteriser [Edit: removed dead, harmful link] is a crowd-funded product intended to extend battery life by boosting the voltage. It is basically a joule thief that is in a tiny package that slips over the cell. Dave Jones of EEVBlog did a video…
JYelton
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Joule Thief - operation and the 'supercharged' version

I've made a Joule Thief, and it works fairly well, but not as well as I would like. It's powering a 3.2v LED from a 1.2v battery, but it's very dim. I'm hoping that increasing the voltage from the JT will improve it, but I'm not sure how to…
Alex Freeman
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A 1USD 11W led bulb circuit and parts analysis

I know this is not a huge deal, but still I want to do it because for Three reasons: 1, it only costs 1 usd. Yep, this is a very cheap led bulb, and I need to take it apart to see if it's trust worthy. 2, It's a great opportunity to learn something…
user83582
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How can I calculate a Joule thief

A Joule thief is a simple step-up converter with which you can drive a 3.6 V LED with a 1.5 V battery even if it is spending the last drops of its life. It merely consists of a transistor, a transformer and a resistor. The circuit is very forgiving…
nansen
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Is a balancing diode really necessary for the Balanced Boost converter?

Please pardon all of the information that precedes the question -- I didn't want you to actually have to go read the paper itself. This question is in two parts, but they are really equivalent, so it's really just one question. This question refers…
MicroservicesOnDDD
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Understanding a Single Transistor Flyback Transformer Driver?

I've been watching a few analyses of CRT flyback transformer drivers and can't understand why the transistor would shut off. To my naive perspective, it appears that the transistor should never shut off due to the positive DC voltage applied…
Sarah Szabo
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Harvesting energy from old batteries?

Old batteries (I mean AA, AAA -sized 1.5v ones) usually have some residual energy, which can be used, for example, to charge mobile phones/pads. I have seen some schematics on the Net, but all of them try to connect old batteries in series without…
Roman Susi
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Ultra low power/ simple flashing circuit

ideally, I want this to run off coin cell batteries. I found a circuit that uses transistors and capacitors, but the voltage requirements are higher than I want. Is there any way I can make this circuit circuit low power? Any other ideas would be…
sfhhd
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Low voltage oscillator for joule thief

I have a transformer with 2 input leads and 3 output leads. I hooked up an LED to 2 of the output and put a dead AA battery on the input and the LED blinked for a second. I have no data on the transformer, but I am wondering if it is possible (and…
skyler
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Checking materials (cheapest possible) to be used for a solar dark-detecting LED light bulb circuit

I want to make this circuit, which is from evilmadscientist.com and includes a Joule Thief: It's for a solar dark-detecting LED light; and I'm trying to follow this guide: https://www.instructables.com/id/Solar-LED-Light-Bulb/?ALLSTEPS I'm having a…
Seven
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How can I measure the output of a voltage booster circuit?

I made this circuit, which was described on-line as a "transformerless Joule Thief." I was able to light four LEDs of varying forward-voltage in series, but I couldn't figure out how to use a multimeter to measure the the total output voltage. …
Annette Gates
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