Panasonic KX-FP80C Service Manual page 194

The following is an overview of how the power supply unit is controlled.
The control method of this power supply unit is pulse width modulation.
When Q is ON, the energy is charged in the transfer primary coil according to E
1
OFF, the energy is output from the secondary transfer as follows.
L D Load
1
Then the power is supplied to the Load. When Q
side. The output voltage is fed back in the control IC according to the error amp rectifier. Then
depending on how T
too large, in order to decrease the voltage output, the increase in
output voltage is stabilized.
Therefore, basically the timing: Ton/Toff of Q1 controls the output voltage.
L
is controlled, stabilization occurs. Also, when the current load becomes
ON
is ON, power is not output from the secondary
1
194
. When Q is
1 1
is controlled and the