Diodes in DC Circuits

To analyze diode circuits, the state of the diode (on or off) must first be found. The diode can then be replaced by the switch equivalent circuit.

Peak Inverse Voltage (PIV)

The peak inverse voltage rating of a diode is the maximum reverse voltage that can be connected across a diode without breakdown.

The maximum power that can be controlled by a single diode is determined by its rated reverse voltage and by its rated forward current.

If the load current is greater than the current rating of a single diode, then two or more diodes can be connected in parallel (see Figure 1) to achieve a higher forward current rating.

To obtain satisfactory and reliable SCR operation, it is necessary to provide protection against over voltages and over currents.

For proper operation of circuits using SCRs, the trigger circuits should supply the firing signal at precisely the correct time to assure turn-on when required.

If an SCR is forward-biased and a gate signal is applied, the device turns on. However, once the anode current I_A is above the holding current, the gate loses control.

There are several low power devices belong to Thyristor family that are mainly used in trigger circuits to turn the thyristor ON.

Controlled rectifiers, or converters, as they are generally called, are broadly classified into full-controlled and half-controlled types.

The ratings of a semiconductor device give the values for the various conditions that a manufacturer recommends for reliable operation of the device.

The maximum power that can be controlled by a single SCR is determined by its rated forward current and rated forward blocking voltage.

The maximum power that can be controlled by a single SCR is determined by its rated forward current and rated forward blocking voltage.