Output Voltage Section - Panasonic KX-NCP500GR Service Manual

KX-NCP500GR
4.6.3.

Output Voltage Section

4.6.3.1. Describes the circuit that converts main converter output to 15V / 15VPT / 41V.
[1] 15V Output Voltage Section
1. 15V Output Converter Section
The 15V output converter section is a separately-excited chopper step-down converter consisting primarily of IC301, D301,
L301, C301 and R301-R303.
Inputs 32V output described in Part 2 as input power source.
Provides 15V by IC301 and D301 on/off switching and L301/C301 smoothing circuit.
Output voltage is determined by resistance ratio of IC301 and R301-R303.
IC301 oscillation frequency is 70 kHz (typ.).
2. 15V Output Overcurrent Protection Section
Protection is provided by overcurrent protection circuit in IC301.
[2] 15VPT Output Voltage Section
1. 15VPT Output Converter Section
The 15VPT output converter section is a separately-excited chopper step-down converter that utilizes 15V output and same
IC and consists primarily of IC401, D401,L401, C401 and R401-R403.
Inputs 32V output described in Part 2 as input power source.
Provides 15VPT by IC401 and D401 on/off switching and L401/C401 smoothing circuit.
Output voltage is determined by resistance ratio of IC401 and R401-R403.
IC401 oscillation frequency is 70 kHz (typ.).
2. 15VPT Output Overcurrent Protection Section
Protection is provided by overcurrent protection circuit in IC401.
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