Kingtronics Blog

There are a number of different electronic devices which tend to be called diodes.

Although they're made differently they all have three things in common.

They have two leads like a resistor.
The current they pass depends upon the voltage between the leads.
They do not obey Ohm's law!

As an example we will use a typical diode called a pn-junction. This allows us to explain behaviour of diodes.

The function of a diode is to allow current in one direction and to block current in the opposite direction.

The terminals of a diode are called the anode and cathode. There are two kinds of semiconductor diodes: a P-N junction diode, which forms an electrical barrier at the interface between N- and P-type semiconductor layers, and a Schottky diode, whose barrier is formed between metal and semiconductor regions.

Remember, however, that there are other sorts of diodes which are built differently but show the same general behaviour.

Variable resistors used as potentiometers have all three terminals connected. This arrangement is normally used to vary voltage, for example to set the switching point of a circuit with a sensor, or control the volume (loudness) in an amplifier circuit. If the terminals at the ends of the track are connected across the power supply then the wiper terminal will provide a voltage which can be varied from zero up to the maximum of the supply.

Kingtronics are potentiometers manufacturer since 1990. Trimming potentiometers are Kingtronics' first products. RKT-3006 is one of the Trimming potentiometers,It is used where very precise adjustments must be made.RKT-3006 has 3 terminal styles:3006W, 3006P, 3006Y. The screw must be turned many times (10+) to move the slider from one end of the track to the other, giving very fine control.

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.

The tantalum capacitor is a highly reliable type of electrolytic capacitor, available in both solid-bodied and separately encased forms.

The encased "wet" variant is not used often in modern designs. Surface mount tantalum capacitors are widely used in circuit designs because of their volumetric efficiency, basic reliability and process compatibility.

Tantalum SMD capacitors are widely used to provide levels of capacitance that are higher than those that can be achieved when using ceramic capacitors.

Solid tantalum chip capacitors are designed and manufactured with the demanding requirements of surface mount technology in mind, there are six cases availble.

We have good quality with RoHS-compliant, have good price and good sevice.

You can find our catalog through http://www.kingtronics.com/products.html pls contact us at any time,we will be pleased to support you!

Photo of product

Tantalum electrolytic capacitors exploit the tendency of tantalum to form a protective oxide surface layer, using tantalum powder, pressed into a pellet shape, as one "plate" of the capacitor, the oxide as the dielectric, and an electrolytic solution or conductive solid as the other "plate". Because the dielectric layer can be very thin (thinner than the similar layer in, for instance, an aluminium electrolytic capacitor), a high capacitance can be achieved in a small volume. Because of the size and weight advantages, tantalum capacitors are attractive for portable telephones, personal computers, and automotive electronics.

Kingtronics short for Kt (logo) produce tantalum capacitors since 1997, include dipped tantalum capacitors (through hole capacitors), general purpose chip tantalum capacitors (surface mount) and Low-ESR chip tantalum capacitors (surface mount).We have a full instruction about Tantalum Capacitors in our website www.kingtronics.com  each series of Tantalum Capacitors have detailed PDF and other information.

Rectifiers find a use in detection of amplitude modulated radio signals. The signal may be amplified before detection, but if un-amplified, a very low voltage drop diode must be used. When using a rectifier for demodulation the capacitor and load resistance must be carefully matched. Too low a capacitance will result in the high frequency carrier passing to the output and too high will result in the capacitor just charging and staying charged.

Kingtronics’s fast recovery rectifier diodes are very popular in the overseas market, According to the rectifier’ s application , Our Kingtronics managing ordinary rectifier diodes, ultra-fast rectifier diodes. In our Kingtronics website www.kingtronics.com ,we have detailed PDF about all kinds of diodes & rectifiers.

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.

NEW Click here to visit Zener-Diode.co.uk for a site dedicated to zener diodes, their characteristics, usage, and other information.

Zener Diode Voltage Regulator Circuit

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. Click here to find out more about the Zener Diode Voltage Regulator and how you go about selecting the resistor and zener diode.
NEW The above mentioned article on zener diode voltage regulators has now been updated and a handy calculator has been added to help you select the correct resistor and zener diode values and power ratings.

Zener Diodes in Series With Loads

If you have a regulated fixed voltage - say 12 Volts from a desktop PC power supply, and you want to power something requiring a lower voltage, it is possible to simply place a zener diode in series with the load device. You would choose a diode with a zener voltage equal to the supply voltage minus the voltage drop across the load.

For example, if you have a 1 Watt 6 Volt lightbulb to power from a 12 Watt regulated power supply, a 6.2V zener diode could be placed in series with the bulb giving the bulb 5.8V, or you could overpower the bulb a little using a 5.6V zener diode and dropping 6.4V across the bulb. Heat would be generated in the zener diode so it is essential to calculate the power lost in it so a suitably rated diode could be chosen.

Using a 5.6V zener diode, and knowing the bulb draws a current of around one-sixth of an Amp, we can calculate the power loss in the diode (with Ohm's Law) to be just under 1 Watt. Therefore a standard 1.3 Watt zener diode should be up to the job.

Circuits with Zener Diodes

Zener diodes are key components in the circuits presented in the following articles: Make a Simple Battery Status Monitor, LM741 Voltage Indicator, and High Capacity Alternative to 9V Battery.

Zener diodes are used to maintain a fixed voltage. They are designed to 'breakdown' in a reliable and non-destructive way so that they can be used in reverse to maintain a fixed voltage across their terminals.

Zener diodes can be distinguished from ordinary diodes by their code and breakdown voltage which are printed on them. Zener diode codes begin BZX... or BZY... Their breakdown voltage is printed with V in place of a decimal point, so 4V7 means 4.7V for example.

Kingtronics supplies BZV55C/ZMM55C-SERIES with Low zener impedance,Low regulation factor,Glass passivated junction,High temperature soldering guaranteed:260 C/10S at terminals. Please link http://www.kingtronics.com/pdf/BZV55C.pdf ,you will see all series of our Zener diodes.

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word crystal is derived from the Ancient Greek word κρύσταλλος (krustallos), meaning "rock-crystal" but also "ice", from κρύος (kruos), "icy cold, frost". The word once referred particularly to quartz, or "rock crystal".

Electronic-grade quartz crystal is single-crystal silica which has properties that make it uniquely useful for accurate frequency controls, timers, and filters in electronic circuits. These devices are utilized for a wide variety of electronic applications in communications equipment, computers, aerospace hardware, instruments for commercial use.

The most common function of a diode is to allow an electric current to pass in one direction (called the diode's forward direction) while blocking current in the opposite direction (the reverse direction). Thus, the diode can be thought of as an electronic version of a check valve. This unidirectional behavior is called rectification, and is used to convert alternating current to direct current, and to extract modulation from radio signals in radio receivers.

Different types of diode will have different function, this is depends on their voltage, temperature, and other factor. So it is very important when you check your diode, Our Kingtronics provide diode's detailed function. If you have any problems, please look for some suggestions in www.kingtronics.com.