IC-4Trigger Coils: Principle, Applications and Key Characteristics

A trigger coil, also known as an ignition coil or high-voltage coil in some contexts, is a critical electronic component designed to generate short-duration high-voltage pulses through electromagnetic induction. It serves as the "starting switch" in various electrical systems, converting low-voltage electrical energy into high-voltage pulses to trigger the operation of other components. Compact in structure yet powerful in function, trigger coils are widely used in daily necessities, industrial equipment and automotive systems, playing an indispensable role in modern technology.

The core working principle of a trigger coil is based on electromagnetic induction, similar to a small transformer but optimized for instant high-voltage output. It mainly consists of two copper wire windings—primary winding and secondary winding—wound around a ferrite or iron core. The primary winding has fewer turns of thicker wire and is connected to a low-voltage power source, while the secondary winding has hundreds or even thousands of turns of thinner wire, responsible for outputting high voltage. When the low-voltage current in the primary winding is suddenly cut off, the magnetic field around the core collapses rapidly, inducing a high-voltage pulse in the secondary winding. This pulse can reach several thousand volts, even tens of thousands of volts, in an extremely short time (usually a few microseconds) to meet the triggering requirements of different devices.For instance, our trigger coil needs to be filled with glue. After filling, there are bubbles in the glue, so we need to put it in a vacuum pump to evacuate the air. To evacuate the air, we need to set the parameters properly

Trigger coils have a wide range of applications across multiple fields. One of the most common applications is in beauty equipment, especially hair removal devices. In hair removal instruments, trigger coils generate high-voltage pulses to activate flash lamps or laser heads, emitting intense light pulses that act on hair follicles to achieve hair removal effects. They also control energy output precisely to ensure safe and effective use without damaging the skin. Another major application is in automotive and motorcycle ignition systems. In motorcycle magnetos, the trigger coil is installed on the stator, and when the rotor’s permanent magnet passes by, it generates a weak current to trigger the thyristor, which then releases stored energy to the ignition coil for high-voltage ignition, enabling the engine to start.

In summary, trigger coils are essential components that bridge low-voltage and high-voltage systems through electromagnetic induction. Their simple structure, reliable performance and wide adaptability make them indispensable in various fields. As 

technology advances, trigger coils will continue to evolve, supporting the development of more efficient, compact and intelligent electrical devices.