Limiting protection circuit elements shown in Figure 24-29. When the current is less than the set value, the R1 offers VT3s bias current, VT3 saturated conduction, can not afford to control the effect of current; when the current is greater than or equal to the set value, R on voltage drop increases, R voltage drop on the transistor junction voltage and 54 datasheet and the voltage drop close to R2, began to limit the current through the VT3, so put the current limit to a certain level. R2 can also be replaced by a regulator, limiting more accurate. The drawback is that when the protection circuit current overload, especially when a short circuit, voltage drop are all on a drop in the transistor, there is a certain power. As needed, to count as a protective circuit ? self-locking. That is when the curren...

Capacitance can produce delays that have the role of the circuit after a period of time the signal word may also use its energy storage role in accelerating the pace of change associated circuitry, as shown in Figure 7-42 (a) shows the capacitance of the circuit shall be a role to accelerate the application of . Figure 7-42 (a) shows a typical inverter circuit, Ri VT for the transistor base input resistance, R2 is the VT of the transistor base bias resistor (connected - Ec guarantee VT reliable cut-off), R3 for the transistor collector load resistors, capacitors, capacitor C is accelerated. as transistors operate as switches, in parallel with capacitor C R1 shield, because the voltage across the capacitor can not change suddenly, because of the input signal after the leading edge along...