01․ How can we protect SCR from thermal conditions ?
Excess amount of heat can be dissipated quickly by mounting the SCR on a heat sink.
02․ Which of the following is used in heat sink?
Aluminium is a good conductor of heat. Silver is the best conductor of heat but it is not used due to its high cost.
03․ Materials used in heat sink should have
A heat sink material should have all these characteristics to radiate heat efficiently and quickly.
04․ What is used to protect a thyristor from high di / dt conditions?
Inductor does not allow sudden change in current through it.
05․ Which of the following is used in SCR to protect from high dV / dt?
Capacitor in series with the resistor is called Snubber circuit which does not allow sudden change in dV / dt.
06․ What happen due to high di / dt?
High di / dt causes localized heat generation.
07․ What may happen high dV / dt?
High dV / dt will breakdown the J2 junction and trigger the SCR.
08․ Why resistor is used in Snubber circuit ?
Capacitor discharges through the resistor. Resistor limits this discharging current.
09․ Snubber circuit is used with SCR
Snubber circuit is used in parallel with SCR to limit high dV / dt across the SCR.
10․ Delay time is defined by the interval when
Delay time is the interval between which gate current rises from 90 % to 100 % of its final value at the same time anode forward leakage current rises to 10 % of its final value as well as anode forward voltage falls to 90 % of its initial value.