Read Sharp 76FW-53H (serv.man13) Service Manual online
Colour Television – DA100/DW100 Chassis
Sharp Electronics (UK) Ltd
Technical Support
September 99
Page 6
DW100 (56FW53H
TO
6FW54H) 16:9
CHASSIS
For models using the DW100 chassis this regulator circuit has been replaced by an integrated circuit
(L4978D).
(L4978D).
This DC-DC converter will operate from a supply between 8v to 55v and produces an output voltage
of between 3v3 and 50v depending on the value of R747 (5v output R747 = 2k7). C741 connected to
pin 3 provides a soft-start routine. If pin 3 is held low then the device will not operate. The frequency
of the internal oscillator is fixed by the value of R706 and C735. Over-current and over-voltage
protection is incorporated into the design of this device.
of between 3v3 and 50v depending on the value of R747 (5v output R747 = 2k7). C741 connected to
pin 3 provides a soft-start routine. If pin 3 is held low then the device will not operate. The frequency
of the internal oscillator is fixed by the value of R706 and C735. Over-current and over-voltage
protection is incorporated into the design of this device.
D722
T701 pin 1
4
11
3
2
14
5,6
13
C721
470
470
C743
100nF
100nF
C735
2n7
2n7
R706
20k
20k
R748
4k7
4k7
IC707
C722
100nF
100nF
L705
D714
C742
68nF
68nF
R747
2k7
2k7
+5v
C741
100nF
100nF
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