Quote:In normal use : transistors T1 and T2 are cut off, they monitors the voltage across Re resistors. It is not necessary to monitor every Re resistors, only one pair is needed. Just monitor those who give similar voltage drop in each half amplifier section.
R4 and R1 set the current limit threshold wich is a function of both the load voltage and the load current, this is also called VI limiter.
Excessive currents in Re resistors will cause T1 and T2 to cut on.
Drive signal is so removed from the gates of mosfet output transistors.
D1 and D2 are "blocking" diodes, they are to inhibit the transistors T1 and T2 from conducting during the opposite half-cycle of signal.
C1, C2 and R2 are set to suppress parasitic oscillations in protection circuit during current limiting action.
This design may be also used as it is with BJT output devices.
The amplifier is protected when output is connected to a charge lower than about 2.5 ohms, or if it's output is short-circuited.
As soon as the short-circuit is removed, the amplifier goes back into normal operation.
Normal charges (8 ohms and 4 ohms load) does not have any effect on the short-circuit protection circuit.
For use with very low charge (eg: 2 ohms load) it is necessary to set R4 and R5 to higher value (150 ohms).

(12-10-2010, 09:22 PM)bjO Wrote: sepertinya mirip ini:


ehmm :-?