joule thief circuit power a white blue led from a 1 5v battery

This circuit is commonly referred to as a Joule Thief, and it has been frequently encountered in various electronics videos on YouTube.

The Joule Thief is a simple, low-cost circuit designed to extract energy from a single-cell battery, particularly when the battery voltage is too low to power conventional devices. It operates using a self-oscillating boost converter topology, which allows it to convert the low voltage of a depleted battery into a higher voltage sufficient to drive an LED or other low-power devices.

The primary components of a Joule Thief circuit include a transistor (usually a bipolar junction transistor), a resistor, a toroidal inductor or transformer, and a light-emitting diode (LED). The circuit typically operates with a 1.5V battery, such as an AA or AAA cell, but can also work with other low-voltage sources.

In operation, when the circuit is powered, the transistor is turned on, allowing current to flow through the inductor, which stores energy in its magnetic field. Once the current reaches a certain level, the transistor turns off, causing the magnetic field to collapse. This collapse induces a voltage spike in the inductor, which can be several times higher than the input voltage. This induced voltage is then used to power the LED.

The resistor in the circuit serves to limit the base current to the transistor, ensuring that it operates within safe parameters. The choice of inductor and its inductance value is crucial, as it affects the frequency of oscillation and the efficiency of energy transfer.

Overall, the Joule Thief is an excellent example of how simple electronic components can be utilized to maximize energy efficiency, making it a popular project for hobbyists and educators in the field of electronics.I`ve seen this circuit around before, but it kept cropping up while looking at other electronics videos on YouTube. It`s called a Joule Thief, and it was.. 🔗 External reference