How does a joule thief work?

The Joule Thief Circuit is a voltage booster circuit which converts a constant low voltage input into a periodic output of a higher voltage. This circuit can be most often seen lighting an LED with an almost dead AA battery. The peaks in voltage occur rapidly, causing the LED to flash at a very fast rate.

Can a joule thief charge a battery?

A “Joule Thief” is a simple voltage booster circuit. Because the Joule Thief is able to boost the voltage of a signal, you are able to charge a battery with a power source whose output voltage is actually lower than the battery itself.

What is joule thief transformer?

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.

What is voltage booster?

A boost converter is a DC to DC converter with an output voltage greater than the source voltage. A boost converter is sometimes called a step-up converter since it “steps up” the source voltage. Since power ( ) must be conserved, the output current is lower than the source current.

How do DC converters work?

DC-DC converters are high-frequency power conversion circuits that use high-frequency switching and inductors, transformers, and capacitors to smooth out switching noise into regulated DC voltages. A boost converter steps a voltage up, producing a voltage higher than the input voltage.

How does voltage step up work?

A transformer converts alternating current (AC) from one voltage to another voltage. It has no moving parts and works on a magnetic induction principle; it can be designed to “step-up” or “step-down” voltage. So a step up transformer increases the voltage and a step down transformer decreases the voltage.

How does a Joule Thief circuit work?

The Joule Thief Circuit is a voltage booster circuit which converts a constant low voltage input into a periodic output of a higher voltage. This circuit can be most often seen lighting an LED with an almost dead AA battery. The peaks in voltage occur rapidly, causing the LED to flash at a very fast rate.

What are some examples of Joule thieves?

Some common ones are 2SC2500, 2SD5041, KSD5041, ZTX1048A, NTE11, SS8050. One example of a low voltage source to which a Joule thief might be applied is a solar cell, or solar PV cell. The typical single solar cell puts out a maximum of about a half volt no load and somewhat lower, maybe 0.45 volts with a load.

Can I use the led directly without the joule thief?

The conventional Joule thief wastes about half of the power, so if you can use the supply voltage directly without the Joule Thief, it can double the battery life. If the supply voltage is above 3.5 volts, then the LED may be connected directly to the supply with just a simple current limiting resistor.