Samsung RE-1200 Service Manual page 39

Touch Control Circuit Descriptions |
3. Timer Pulse Shaping Circuit
Converts sinuous waveform of 50Hz into shaped waveform.
This pulse becomes the time base of timer in the microcomputers.
73081 (IC1) and supplies zero-crossing point signal for power control relay triggering.
Figure 43 shows the schematic configuration.
Figure 44 shows the waveform of the each section in Figure 43.
vec
-5VDC
D1
US1040
FROM R4
(A)
TO PIN 15
(B) OF IC
D2
US1040
(Fig. 43) Pulse Shaping Circuit
Waveform of (A)
OV
~ 5VDC
Waveform of (B)
t
{
t
'
1
'
1
{
I
{
OV
-5VDC
(Fig. 44) Waveform of Each Section in Figure 43.
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