SAMSUNG protect circuit with LA76931
Saturday, April 7, 2012 by skemarangkaian
Following is the protect circuit Samsung TV which use IC LA76931 as basic working the protect circuit. This Protect Circuit LA76891 located at pin-30 whichconnected to the collector of transistor Q902.In normal conditions the voltage at the base of Q902 is "low" and the voltage at pin-30 is "high". For the temporary crippling protect, it can be removed Q902 (or to the emitter-base short).
SAMSUNG protect circuit with LA76931 |
Vertical Protect. Pulses of the vertical-out rectified by diode D355, so that the base voltage is approximately 0.6V Q904 ,and collector voltage is 0v.
X-ray Protect (option). Sampled using a heater voltage of the circuit as shown below. Normal vltage in x-ray path to the base of Q902 is zero.