Electronics

Figure 1(a) shows a boost converter, another basic topology for converters. A boost converter always steps the voltage up. The theory of operation is similar to that for a buck converter in some ways but very different in others. Boost Converter Working For instance, when the pulse is high, the switch is closed and energy […]

Figure 1(a) shows a buck converter, the most basic topology for converters. A buck converter always steps the voltage down. A transistor, either a bipolar junction or a power FET, is used as the switching device. A rectangular signal out of the pulse-width modulator closes and opens the switch. A comparator controls the duty cycle

Thyristor is a generic term for a broad range of semiconductor components used as an electronic switch. Like a mechanical switch it has only two states: on (conducting) and off (not conducting). Thyristors have no linear in-between state as transistors have. In addition to switching, they can also be used to adjust the amount of

Triac Working The triac is a three-terminal device essentially equivalent to two SCRs joined in reverse parallel (paralleled but with the polarity reversed) and with their gates connected together. The result is a bidirectional electronic switch that can be used to provide load current during both halves of the AC supply voltage. Triac connections, shown

Reverse Recovery Characteristics of Power Diode Ideally, a diode should have no reverse recovery time. However, the manufacturing cost of such a diode may increase. In many applications, the effects of reverse recovery time is not significant, and inexpensive diodes can be used. Depending on the recovery characteristics and manufacturing techniques, the power diodes can

TRIAC (Triode thyristor for alternating current) or triac is a bi-directional thyristor switch mainly used for AC control applications. It conducts in both directions, unlike the thyristors (SRCs) which conduct in one direction only. It can be considered to be equivalent to two thyristors connected in anti-parallel but having only three terminals. It has a

Static Characteristics of SCR Figure 1(a) shows the circuit symbol and the conventions for the different variables used in the V-I characteristics of the thyristor, shown in Fig. 1(b). The different modes describing the V-I characteristics are as follows: 1. Forward blocking mode: In Fig. 1(b), in forward blocking mode, when gate current IG =

Thyristors are a family of semiconductor switches having four or more layers, that is, p-n-p-n type of structure. Nowadays, thyrsitors with blocking voltage in excess of 6 kV and continuous current rating in excess of 4 kA are available. In a thyristor, if the ohmic connection is made to the first p-region and the last

The insulated gate bipolar transistor (IGBT) combines the advantageous features of MOSFET (such as voltage control, fast switching) and BJT (such as low ON-state losses and high OFF-state voltage capability. These devices have near ideal characteristics for high voltage (>100V) and medium frequency (<20 kHz) applications. The IGBT is a three terminal device with Like

A power MOSFET is a metal oxide semiconductor field effect transistor. It is a three-terminal, voltage controlled majority carrier device and has a source lead (S), drain lead (D) and gate lead (G) similar to emitter, collector and base of a transistor, respectively. The movement of the majority carriers in a MOSFET is controlled by