What Are Adjustable Inductors, And How Do They Work?

An adjustable inductor is a commonly used inductive device. Common adjustable inductors include oscillating coils for semiconductor radios, line oscillating coils for TV sets, line linear coils, intermediate frequency trap coils, frequency compensation coils for audio, and wave-blocking coils.

Why are they used?

Adjustable inductors are often used in power supplies and other electronic devices because they allow for fine-tuning of the voltage and current output. They work by using a coil to change the magnetic field, which in turn changes the current through the coil.

How Does an Adjustable Inductor Work?

1. The oscillating coil used in the semiconductor radio and the variable capacitor form a local oscillation circuit in the semiconductor radio, which is used to generate a local oscillation signal whose radio signal received by the input tuning circuit is higher than 465kHz. The basic structure is composed of a metal shield, a nylon liner, an I-shaped magnetic core, a magnetic cap, and a pin seat, and a winding made of high-strength enameled wire is used on the I-shaped magnetic core. The magnetic cap is mounted on the nylon frame in the shield, which can be rotated up and down, and the inductance of the coil can be changed by changing the distance between it and the coil.
2. The line oscillating coil for TV was used in early black and white TV sets. It formed a self-excited oscillation circuit with peripheral resistance-capacitance elements and line oscillating transistors, which were used to generate a rectangular pulse voltage signal with a frequency of 15625HZ. There is a square hole in the center of the magnetic core of the coil, and the line synchronization adjustment knob is directly inserted into the square hole, and the relative distance between the magnetic core and the coil can be changed by rotating the line synchronization adjustment knob, thereby changing the inductance of the coil.
3. Line linear coil is a nonlinear magnetic saturation inductance coil (its inductance decreases with the increase of current), it is generally connected in series in the line deflection coil loop, and its magnetic saturation characteristics are used to compensate for the linearity of the image distortion.

Products in GFOOKIC

Take the adjustable inductor numbered A1313B-0032GGH=P3 as an example. The temperature range of this product is -40℃～85℃. It has undergone heat resistance, humidity resistance, vibration resistance, and ESD tests. It is a professionally available adjustable Inductor. In particular, it has passed the ROSH quality certification, reaching the lead-free standard, and the quality is safe and reliable.