Panasonic DMR-E55PL Servise Manual

Panasonic DMR-E55PL Servise Manual Manual pdf 9 page image

2. Equivalence Circuit to IC11503. Startup CircuitWhen power is turned on, input voltage of the SwitchingTransformer is supplied to IC1150 as the startup power.After IC1150 has started, the startup current is cut off.The current of Startup Circuit is supplied as constantcurrent source in IC1150 and as charge current for thecapacitor connected between Vcc terminal and GND outside of IC1150 until Vcc reaches 14.4V.When Vcc reaches 14.4V, the Startup Circuit is cut off, thenoscillation starts.After then, power of IC1150 is supplied from control coil.In case, the power failure or short out of the load, when Vccbecomes 9.0V; the oscillation stops, furthermore Vccbecomes 7.1V the Startup Circuit starts up and Vcc starts torise.Pin No. Symbol Description1 Z/C Trigger input terminal.Zero detection voltage: 0.25VIt becomes less than 3V, the mode turns tostandby.2 F/B Bias current feedback input terminal.lSwitching ON time (min.) ~ (max.)1.5V ~ 4.5V / 0μsec. ~ 25μsec.lIn standby modeOscillation stops:less than 0.8VOscillation starts: over 1.8V3 GND GND terminal4 Vcc Power terminal of IC.Oscillation starting voltage: Vcc = and over 14.5VOscillation stop voltage: Vcc = and less than 9.6VOver voltage latching voltage: Vcc = 20V5 Drain Drain terminal for Main switching material.7 New Features7.1. Function of Power Circuit (IC1150)1. GeneralWe adopted IC module as the Switching Power Circuit for lower power consumption.IC1150 is constructed with Switching materials and Control IC, and is partial resonance module.We realized Switching Power with high efficiency, low noise and low power consumption.9DMR-E55PL