A Zener Diode is a special kind of diode which permits current to flow in the forward direction as normal, but will also allow it to flow in the reverse direction when the voltage is above a certain value - the breakdown voltage known as the Zener voltage.

The Zener voltage of a standard diode is high, but if a reverse current above that value is allowed to pass through it, the diode is permanently damaged. Zener diodes are designed so that their Zener voltage is much lower - for example just 2.4 Volts. When a reverse current above the Zener voltage passes through a Zener diode, there is a controlled breakdown which does not damage the diode. The voltage drop across the Zener diode is equal to the Zener voltage of that diode no matter how high the reverse bias voltage is above the Zener voltage.

The illustration above shows this phenomenon in a Current vs. Voltage graph. With a Zener diode connected in the forward direction, it behaves exactly the same as a standard diode - i.e. a small voltage drop of 0.3 to 0.7V with current flowing through pretty much unrestricted. In the reverse direction however there is a very small leakage current between 0V and the Zener voltage - i.e. just a tiny amount of current is able to flow. Then, when the voltage reaches the breakdown voltage (Vz), suddenly current can flow freely through it.

Uses of Zener Diodes

Since the voltage dropped across a Zener Diode is a known and fixed value, Zener diodes are typically used to regulate the voltage in electric circuits. Using a resistor to ensure that the current passing through the Zener diode is at least 5mA (0.005 Amps), the circuit designer knows that the voltage drop across the diode is exactly equal to the Zener voltage of the diode.

A Zener diode can be used to make a simple voltage regulation circuit as pictured above. The output voltage is fixed at the Zener voltage of the Zener diode used and so can be used to power devices requiring a fixed voltage.

If you have any inquiry about Zener diode, pls contact info@kingtronics.com

The principal "active" element of the Surge Arrester is a metal oxide varistor characterized by high non-linearity. At a working voltage mainly a capacity current flows smaller than 1 mA. Any voltage increase causes a large increase of current flowing through the varistor, leading in turn to immediate limitation of further voltage increase on arrester terminals. When the over voltage disappears, the arrester immediately returns to its basic state.

Surge Arresters are equipped with a disconnecting device that disconnects the arrester from the network if it becomes damaged as the result of over voltage of too high energy or inadmissible voltage increase in the system. If such a situation occurs then the bottom terminal of the disconnecting device is "rejected" by the spring inside. This terminal remains suspended on an insulation "leash".

Kingtronics sell 2-Electrode arresters and 3-Electrode arresters. Following are 2-Electrode arresters and 3-Electrode arresters’s pictures.

A potentiometer with a resistive load, showing equivalent fixed resistors for clarity.

The potentiometer can be used as a voltage divider to obtain a manually adjustable output voltage at the slider (wiper) from a fixed input voltage applied across the two ends of the potentiometer. This is the most common use of them.

The voltage across RL can be calculated by:
V_\mathrm{L} = { R_2 R_\mathrm{L} \over R_1 R_\mathrm{L} + R_2 R_\mathrm{L} + R_1 R_2}\cdot V_s.

If RL is large compared to the other resistances (like the input to an operational amplifier), the output voltage can be approximated by the simpler equation:

V_\mathrm{L} = { R_2 \over R_1 + R_2 }\cdot V_s.

As an example, assume

V_\mathrm{S} = 10\ \mathrm{V}R_1 = 1\ \mathrm{k \Omega}R_2 = 2\ \mathrm{k \Omega}, and R_\mathrm{L} = 100\ \mathrm{k \Omega}.

Since the load resistance is large compared to the other resistances, the output voltage VL will be approximately:

{2\ \mathrm{k \Omega} \over 1\ \mathrm{k \Omega} + 2\ \mathrm{k \Omega} } \cdot 10\ \mathrm{V} = {2 \over 3} \cdot 10\ \mathrm{V} \approx 6.667\ \mathrm{V}.

Due to the load resistance, however, it will actually be slightly lower: ≈ 6.623 V.

One of the advantages of the potential divider compared to a variable resistor in series with the source is that, while variable resistors have a maximum resistance where some current will always flow, dividers are able to vary the output voltage from maximum (VS) to ground (zero volts) as the wiper moves from one end of the potentiometer to the other. There is, however, always a small amount of contact resistance.

In addition, the load resistance is often not known and therefore simply placing a variable resistor in series with the load could have a negligible effect or an excessive effect, depending on the load.

Diodes can switch analog signals. A reverse biased diode appears to be an open circuit. A forward biased diode is a low resistance conductor. The only problem is isolating the AC signal being switched from the DC control signal. The circuit in Figure below is a parallel resonant network: resonant tuning inductor paralleled by one (or more) of the switched resonator capacitors. This parallel LC resonant circuit could be a preselector filter for a radio receiver. It could be the frequency determining network of an oscillator (not shown). The digital control lines may be driven by a microprocessor interface.

Kingtronics www.kingtronics.com provide Fast Switching Diode LL4148 Minimelf SOD80 .The features of Fast Switching Diode LL4148 Minimelf SOD80 are below:

  • LL4148 small signal diode
  • Fast switching surface mount diode
  • Low reverse leakage
  • Fast switching speed
  • Maximum power dissipation 500mW
  • High stability and high reliability

A capacitor is a passive electronic component consisting of a pair of conductors separated by a dielectric.

Kingtronics specializes in application specific multilayer ceramic capacitors. Our product offerings included surface mount capacitors from the 0402 case size to larger high voltage units (up to 4KV) for Commercial and High Reliability applications.

The NPO model from Kingtronics International Company is a series of multilayer chip-type ceramic capacitors that has 0.5pF to 10uF capacitance, with up to 10 percent tolerance.

The 0805-packaged MLCC is rated at 6.3V to 50V for low voltage chip ceramic capacitor and from 63V to 4kV for high voltage multilayer ceramic capacitor.

Our products LKT Chip multilayer ceramic capacitors 6.3V to 50V  and   HKT High voltage multilayer ceramic capacitors 63V to 4000V are marketed under our own brand "Kingtronics" and enjoy a very good reputation around the world. Many customers approved our product brand "Kingtronics" and appointed to order.

Quartz is used in the making of sandpaper, optics, glass, liquid filters, circuit boards, computer components, cement, mortar, and jewelry. Quartz crystals are also piezoelectric meaning when an electrical current passes through them they vibrate a small amount. Time can be measured from the vibrations of the quartz crystals so quartz crystals are often used in clocks.

Quartz crystals may either operate in a fundamental mode or in an overtone mode. Below frequencies of around 25 MHz crystals are normally designed to operate in their fundamental mode, whereas above this they will normally be designed for overtone operation, although with manufacturing techniques improving higher frequency crystals are becoming available. The mode is therefore an important element of the crystal specification.




As a low cost alternative to molded tantalum capacitors , constructed in a tough, radial dipped flame retardant plastic case, assures the user that it is a top performer with such attributes as low DCL, low ESR, low impedance and a great value with low in-place cost. Dipped tantalum capacitors is high shock and vibration resistant and is available in bulk or on radial tape and reel.

Kingtronics TKT series dipped tantalum capacitor, also called radial tantalum capacitors, or tantalum bead capacitors. TKT series meets and exceeds the requirements of IEC Specification 384-15-3, IECQ Specification QC300201/US003 and Technical Specification SJ/T10856-96. Dipped tantalum capacitors are used in military (on request) and civil applications such as TV sets, camcorders, computers, program-controlled electronic telephone switching systems, telephones, instruments and meters.

For the detailed information for TKT series tantalum capacitors, Kingtronics made a PDF in www.kingtronics.com.

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

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



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