Nov. 1997 © TOSHIBA
18 - 53
4560/4570 RADF
18.11.2
+5V power circuit
This is a circuit which generates DC +5V voltage supplied to CPUs, logic ICs, etc. DC +24V supplied
from CN5 is dropped to +5V by a 3-terminal regulator IC9. In this circuit, R65 and R64 are protective
resistors which compensate for the power loss occurring due to the generation of +5V. When current
consumption for the +5V line is approx. 80 mA or less, the power loss is compensated for by R65 and IC9
but when the consumption current value exceeds 80 mA, the input voltage at IC9-pin 1 decreases due to
voltage drop in R65. When the emitter voltage of Q13 becomes 0.6V lower than its base voltage, Q13
starts conducting and by making excess current flow through R64, shares a part of the power loss.
In this way, by varying the protective resistance value with the magnitude of consumption current, the
heat caused by the power loss is distributed and dissipated.
Содержание 4560
Страница 210: ...Nov 1997 TOSHIBA 13 43 4560 4570 ADU 13 8 7 Harness connection diagram ...
Страница 213: ...4560 4570 ADU 13 46 Nov 1997 TOSHIBA 13 8 9 PC board assembly ...
Страница 238: ...Nov 1997 TOSHIBA 14 25 4560 4570 CIRCUIT DIAGRAMS 14 5 Power Supply Circuit PS ACC A 115V ...
Страница 239: ...4560 4570 CIRCUIT DIAGRAMS 14 26 Nov 1997 TOSHIBA B 230V ...
Страница 243: ...Nov 1997 TOSHIBA 16 1 4560 4570 PC BOARD 16 PC BOARD ASSEMBLY 16 1 PWA LGC ...
Страница 244: ...4560 4570 PC BOARD 16 2 Nov 1997 TOSHIBA 16 2 PWA PNL ...
Страница 245: ...Nov 1997 TOSHIBA 16 3 4560 4570 PC BOARD 16 3 PWA KEY1 16 4 PWA KEY2 ...
Страница 246: ...4560 4570 PC BOARD 16 4 Nov 1997 TOSHIBA 16 5 PWA ERS ...
Страница 247: ...Nov 1997 TOSHIBA 16 5 4560 4570 PC BOARD 16 6 PS ACC A 115V ...
Страница 248: ...4560 4570 PC BOARD 16 6 Nov 1997 TOSHIBA B 230V ...
Страница 249: ...Nov 1997 TOSHIBA 16 7 4560 4570 PC BOARD 16 7 PS HVT ...
Страница 341: ...Nov 1997 TOSHIBA 18 83 4560 4570 RADF 18 16 Circuit Diagrams Wire Harness 18 16 1 General circuit diagram ...
Страница 342: ...4560 4570 RADF 18 84 Nov 1997 TOSHIBA 18 16 2 Control PC board circuit PWA F LGC 770 ...
Страница 343: ...Nov 1997 TOSHIBA 18 85 4560 4570 RADF 18 16 3 Harness connection ...