Panasonic DMR-E85HP, Service Manual

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2. Equivalence Circuit to IC1150
3. Startup Circuit
When power is turned on, input voltage of the Switching
Transformer 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 constant
current source in IC1150 and as charge current for the
capacitor connected between Vcc terminal and GND out
side of IC1150 until Vcc reaches 14.4V.
When Vcc reaches 14.4V, the Startup Circuit is cut off, then
oscillation starts.
After then, power of IC1150 is supplied from control coil.
In case, the power failure or short out of the load, when Vcc
becomes 9.0V; the oscillation stops, furthermore Vcc
becomes 7.1V the Startup Circuit starts up and Vcc starts to
rise.
Pin No. Symbol Description
1 Z/C Trigger input terminal.
Zero detection voltage: 0.25V
It becomes less than 3V, the mode turns to
standby.
2 F/B Bias current feedback input terminal.
l
Switching ON time (min.) ~ (max.)
1.5V ~ 4.5V / 0µsec. ~ 25µsec.
l
In standby mode
Oscillation stops: less than 0.8V
Oscillation starts: over 1.8V
3 GND GND terminal
4 Vcc Power terminal of IC.
Oscillation starting voltage: Vcc = and over 14.5V
Oscillation stop voltage: Vcc = and less than 9.6V
Over voltage latching voltage: Vcc = 20V
5 Drain Drain terminal for Main switching material.
7 New Features
7.1. Function of Power Circuit (IC1150)
1. General
We 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.
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DMR-E85HP / DMR-E85HPC