Dielectric Voltage - The dielectric (insulation of Potentiometer "guts" to the body) rating is especially important if the Potentiometer is connected to mains operated, non-isolated equipment. Wall mounted lamp dimmers and such are typical examples. This is not commonly specified, but for safety, should be at least 2.5kV. A common way to achieve this is to use a plastic shaft, with the body of the Potentiometer insulated from the chassis, and inaccessible by the user - even if the knob falls off or is removed! This point cannot be stressed highly enough.

Most standard Potentiometer will safely withstand (maybe) 100V or so between the resistance element and terminals, and the body and shaft. Miniature types will usually be less than this. Never, ever, use a standard Potentiometer with a metal shaft to control direct mains operated equipment. Even if the Potentiometer case is earthed, the voltage rating between the internal element(s) and terminals to the case is often unspecified, and is almost always completely unsuited to mains voltages.

Ceramic chip capacitors should be stored in normal working environments. While the chips themselves are quite robust in other environments, solder ability will be degraded by exposure to high temperatures, high humidity, corrosive atmospheres, and long term storage. In addition, packaging materials will be degraded by high temperature – reels may soften or warp, and tape peel force may increase. Kingtronics International Company recommends that maximum storage temperature not exceed 40℃, and maximum storage humidity not exceed 70% relative humidity. In addition, temperature fluctuations should be minimized to avoid condensation on the parts, and atmospheres should be free of chlorine and sulfur bearing compounds. For optimized solder ability, chip stock should be used promptly, preferably within 1.5 years of receipt

The temperature stability is another important area of the crystal specification and it is the allowable frequency deviation as the temperature varies. Again normally expressed in ppm, from the frequency at the reference temperature per degree Celsius. Sometimes the crystal specification may use a frequency tolerance consisting of the sum of the calibration and temperature stability tolerances is quoted.

Over the Operating Temperature Range, an amount of total deviation acceptable for the application. Tighter specifications of Stability lower yield in Quartz Crystal Blank production thereby serving to increase production costs

Kingtronics offers high quality quartz crystal at incredibly aggressive prices. The HC49S series is an industry standard crystal package. HC49S is a low cost, low profile timing option for applications where cost is critical.

The HC49S is available in tight tolerances and stabilities for demanding applications. With a broad frequency range from 3.200MHz to 90.000 MHz, the HC49S can serve as a low cost solution in virtually any application or market.

Tantalum Capacitors offer many advantages over other types of capacitor. This has meant that their use has risen considerably over the years, and now they are widely used in all forms of electronics equipment. The advantages of Tantalum Capacitors can be summarised:

Volumetric efficiency: Tantalum Capacitors offer a very high level of volumetric efficiency - much greater than many other types. In particular they are better than electrolytic capacitors which are their main rival.

Good frequency characteristics: The frequency response of Tantalum Capacitors is superior to that of electrolytic capacitors. This means that they are more suitable for use in a number of applications where electrolytics could not be used.

High reliability: Tantalum Capacitors are more reliable than many other forms of capacitor. Provided they are operated within their ratings they are able to provide an almost unlimited life. Their use is not time limited as in the case of electrolytic capacitors.

Wide operating temperature range: Tantalum Capacitors are able to operate over a very wide temperature range. They are often specified for operating over the range -55℃ to +125℃. This makes them an ideal choice for use in equipment for use in harsh environmental conditions.

Compatibility with modern production methods: Modern production techniques often expose components to high temperatures during soldering as the whole assembly is heated by infra-red heat. Using conventional leaded components only the board surface was heated and the amount of heat conducted by the leads was usually insufficient to damage the components. Tantalum capacitors are able to withstand the temperatures of SMT production and are there fore ideal for use in many new electronics designs.

Kingtronics produced tantalum capacitor since 1997, including dipped tantalum capacitors (through hole capacitors), general purpose chip tantalum capacitors (surface mount). Now the raw material of chip tantalum capacitor is in great shortage, its price is unstable and will increase at any time, without any cutoff date!

In case you have any inquiry for chip tantalum capacitor, please send to us (info@kingtronics.com) at earliest before the price jumping up!

Kingtronics can offer 4 cases: A Case, B Case, C Case and D Case! Tolerance can be +/-20% and +/-10%

For A Case: capacitance can be from 0.1uF until 33uF and voltage can be from 6.3V until 50V
For B Case: capacitance can be from 0.47uF until 100uF and voltage can be from 6.3V until 50V
For C Case: capacitance can be from 1uF until 220uF and voltage can be from 6.3V until 50V
For D Case: capacitance can be from 1uF until 220uF and voltage can be from 6.3V until 50V

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.

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

About

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
electronicAsia-2019
electronicAsia-2019
Convention and Exhibition Centre,HongKong
Date: 13-16 October, 2019
Booth No.: 5G-C26

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

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