A trimmer or preset[1] is a miniature adjustable electrical component. It is meant to be set correctly when installed in some device, and never seen or adjusted by the device's user. Trimmers can be variable resistors (potentiometers), variable capacitors, trimmable inductors. They are common in precision circuitry like A/V components, and may need to be adjusted when the equipment is serviced. Unlike many other variable controls, trimmers are mounted directly on circuit boards, turned with a small screwdriver and rated for many fewer adjustments over their lifetime. Trimmers like trimmable inductors and trimmable capacitors are usually found in superhet radio and television receivers, in the Intermediate frequency, oscillator and RF circuits. They are adjusted into the right position during the alignment procedure of the receiver.

Trimmers come in a variety of sizes and levels of precision; for example, multi-turn trim potentiometers exist, in which it takes several turns of the adjustment screw to reach the end value, allowing for very high degrees of accuracy.

Since 1990 , Kingtronics International company founded its first factory in mainland of China . For 20 years development and experience in manufacturing timpots , Kingtronics brand is well known by more and more pepole .

Now Kingtronics offer Bourns equivalence: 3006, 3266, 3296,  3323, 3329, 3362, 3386,3309, 3540, 3590 . If you want more details ,please visit website: www.kingtronics.com for full specification.

Kingtronics trimming potentiometer

Lightning Arresters are protective devices for limiting surge voltages due to lightning strikes or equipment faults or other events, to prevent damage to equipment and disruption of service. Also called surge arresters.

Lightning Arresters are installed on many different pieces of equipment such as power poles and towers, power transformers, circuit breakers, bus structures, and steel superstructures in substations.

Lightning arrester on distribution pole transformer:

Kingtronics is one HK based manufacturer for electronics component since 1990. Now Kingtronics is an old brand and we also have enjoyed high reputation in electronics component field, especially for radial and axial multilayer ceramic capacitor!
Now fewer and fewer factories produce radial & axial lead mono capacitors, while Kingtronics still keep strong on radial multilayer ceramic capacitors and axial lead,

We have excellent support on radial MLCC capacitor,
***3-4 weeks delivery
***unbeatable price
***stable and high quality
***low MOQ
In case you have any inquiry for radial and axial multilayer ceramic capacitor, please feel free to contact us: info@kingtronics.com
MKT--Radial multilayer ceramic capacitor (mono cap)
0.1uF 50V Y5V +/-20% P:2.54mm Bulk RoHS
4700pF 50V +/-10% X7R P: 2.54mm Bulk RoHS
100pF 50V NPO +/-5% P: 2.54mm Bulk RoHS

AKT--axial lead, multilayer ceramic capacitors
0.1uF 50V +80-20% Y5V Ammo RoHS

There are Trimming Potentiometer (aka trimmers) - pots designed for "set and forget" applications. They are used for "trimming" the value of a resistor, and are commonly used for calibrating instruments, setting the bias current on power amplifiers, and a host of other areas where a circuit cannot be relied upon to give an exact gain, output voltage, or current. Naturally, a normal panel pot can be used, but these are very much bigger, and any calibration or setup control should not be made available for everyone to fiddle with as they please.

This is a very small sample of those available. The first and fourth are multi-turn types, and these should be used when a very precise setting is required. Because they are sealed, they are relatively immune from contamination, and for all but the most trivial application, should be used instead of the open types. Trimming Potentiometer(as shown) are generally available as vertical or horizontal - the choice is usually made based on ease of adjustment of the final circuit.

Diode rectifier M7:  Lead time: 3-4 weeks

Price is much better than Diotec, Panjit, Vishay, Onsemi...

Welcome to send inquiry to us!

Diode Package:

Last shortage of tantalum capacitors happened in 2000, this year 2010, tantalum shortage happened again. It seems every 10 years, tantalum capacitors shortage happens.

AVX TAP series is dipped tantalum capacitors, their lead time is more than 50 weeks. Vishay announce of allocation of dipped tantalum capacitors. Kemet's lead time are very long too.

Kingtronics also face the same problem of tantalum powder shortage and tantalum wire shortage, however, our delivery situation are slowly improving. Especially dipped tantalum capacitors, sometimes we have stock.

Please visit our website:  http://www.kingtronics.com/tantalum-capacitors/
You can download our tantalum datasheet and cross reference. Welcome to send us inquiry for tantalum capacitors: info@kingtronics.com

Gas-filled surge arresters are classical components for protecting the installations of the telecommunications. It is essential that IT and telecommunications systems -with their high-grade but sensitive electronic circuits – be protected by arresters. They are thus fitted at the input of the power supply system together with varistors and at the connection points to telecommunication lines. They have become equally indispensable for protecting base stations in mobile telephone systems as well as extensive cable television (CATV) networks with their repeaters and distribution systems.

These protective components are also indispensable in other sectors:

  • In AC power transmission systems, they are often used with current-limiting varistors
  • In customer premises equipment such as DSL modems,WLAN routers, TV sets and cable modems
  • In air-conditioning equipment

The integral black-box concept offers graduated protection by combining arresters with varistors, PTC thermistors, diodes and inductors to create an ideal solution for many applications.

Crystal oscillators are used in a variety of applications. In some instances crystal oscillators may be used to provide a cheap clock signal for use in a digital or logic circuit. In other instances they may used to provide an RF signal source. In view of the fact that quartz crystals offer a very high level of Q and they are stable, crystal oscillators are often used in oscillator circuits to provide stable, accurate radio frequency signals.

There is a great number of different types of circuit that can be used for crystal oscillators, each one having its own advantages and disadvantages. One of the most common circuits used for crystal oscillators is the Colpitts configuration as shown below.

In this configuration, the crystal operates in a parallel mode. When running in this mode, the crystal should be presented with a load capacitance to operate on its correct frequency. This load capacitance is specified with the crystal and is typically 20 or 30 pF. The crystal oscillator circuit will be designed to present this capacitance to the crystal. Most of this will be made up by the two capacitors C1 and C2, although the remaining elements of the circuit will provide some capacitance.

About Zener Diodes

16 Dec 2010

Functionally, Zener diodes are used as regulators, limiters and to control output switching. When used as regulators, the constant reverse voltage of Zener diodes allows for the regulation of output voltage against both variations in the input voltage from an unregulated power supply and from variations in the load resistance. The current traveling through Zener diodes changes to keep the voltage within the threshold of Zener action and the maximum power it can dissipate. Zener regulators tend to most efficiently function when constant voltage is applied, especially when used in conjunction with regulated power supplies, and for limiter applications.

Zener limiters are constructed with two opposing Zener diodes. Each individual diode can limit one side of a sinusoidal waveform to Zener voltage while keeping the other side near zero. When the two opposing Zener diodes are paired, the waveform is limited to Zener voltage on both polarities.

Zener diodes are also used to control output switching. In this application, Zener diodes switch the output between voltages. This is determined by the changes in input voltage through the diode. The output circuit amounts to a Zener regulator that switches from one Zener voltage to the other on transition through the Zener diode.

Kingtronics supply all kinds of Zener Diodes BZV55C & ZMM55C, http://www.kingtronics.com/pdf/BZV55C.pdf has detailed introduce Zener Diode’s features and types.

Multilayer ceramic capacitors consist of electrodes, the interleaved ceramic dielectric and the external terminal connectors. The capacitance is given by the description:

A = Electrode area
n = Number of active layers
d = Distance between electrodes
εr = Dielectric relative
ε0 = Dielectric constant

Whilst the values “A x n” and “d” are respectively determined by the production process the dielectric constant is a function of the ceramic material used.

Contact us

Tel: (86) 769 8118 8110
Tel: (852) 8106 7033
Fax: (852) 8106 7099
E-mail: info@kingtronics.com
Skype: kingtronics.sales
MSN: kingtronics-sales@hotmail.com
Web: www.Kingtronics.com


Kingtronics International Company was established in 1995 located in Dongguan City of China to handle all sales & marketing for factories located in Chengdu, Sichuan and Zhaoqing, Guangdong, China. In 1990, we established the first factory to produce trimming potentiometer and in 1999 we built up new factory in Zhao Qing, Guangdong. Now with around 850 workers, Kingtronics produce trimming potentiometers, dipped tantalum capacitors, multilayer ceramic capacitors, and diode & bridge rectifier. We sell good quality under our brand Kingtronics, and Kt, King, Kingtronics are our three trademarks. All our products are RoHS compliant, and our bridge rectifier have UL approval. Please visit our Products page, you could please download all our PDF datasheet and find cross reference for our Trimming Potentiometer and capacitors.

Tantalum and Ceramic Capacitors Cross Reference ↓ Download
Diodes & Rectifiers List(PDF: 97KB) ↓ Download
Trimming Potentiometer Cross Reference ↓Download

Meet Kingtronics in Moscow soon
Convention and Exhibition Centre,HongKong
Date: 13-16 October, 2019
Booth No.: 5G-C26

Meet Kingtronics in Munich soon
New Munich Trade Fair Centre, Germany
Date: 10-13 November, 2020
Booth No.: To be advised