Panasonic KX-TA1232, Service Manual

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Rectifier and Smoothing Section
The input signal is full-wave rectified by bridge diode D400, and smoothed by C408, C409,
resulting in a DC current. TH401 and TH402 are power thermistors.
Switching Section
The switching section is a basic RCC type which uses the IC400 included power MOS.FET. D401,
R403 and C412 are for resetting the excitation energy stored in T400 while T400 is OFF. C410 and
R408 are used as a snuffer for FET in IC400.
Control Section
IC400 is a RCC type switching regulator adopted power MOS.FET. The external circuit of IC400
has the following roles.
R401, R402, C111: For starting
R400: For detecting an electric current
C417: For adjusting over current detector level
R404, C414: For compensating phase
R407, C415: For compensating over current protector circuit parts temperature dependence
PC400: For feed back
+15 V Circuit
There are 2 output of switching transformer, T400 and +15 V is generated from the circuit
connected to pin 12, 13-11. +15 V cannot be stabilized by oscillation control of the primary side
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