So that the circuit becomes, Thus,
5 To find From equation (5) 6 To find 7 WKT 8 To find From equation (7), Sub equation (7),
Let 9 s = 10 To find Differentiating equation (9), WRT Now multiply and divide by by equation (9) 11
Relation between S and Multiply and divide by 12 Relation between S and by equation (11) BIAS COMPENSATION: Compensation techniques use temperature sensitive devices such as diode, transistors, thermistors, sensistors etc. to maintain operating point constant. THERMISTOR COMPENSATION: Thermistors have a negative temperature co-efficient ie. Its resistance decrease exponentially with increase in temperature as shown below. Slope of this curve = Where temperature coefficient for thermistor. It is negative. Therefore, thermistors are said to have negative temperature coefficient of resistance (NTC).
FIRST TYPE: COMPENSATION TECHNIQUE: Consider the circuit shown below. Here in the circuit, is ( Thermistor resistor), which has NTC. Thus the original increase in is compensated and Q- Point is made stable.