Specifications

CA10 Course Notes
Sharp Electronics (UK) Limited
CE Technical Support GroupPage 20
Figure 19 : Sand Castle Pulse
Figure 20 : Sand Castle Pulse Detail
R625 and R626 provide a load for the line pulse and R615 limits the current/voltage supplied. C618
suppresses any high frequency signals that may occur on the line pulse. These would be undesirable as
they may cause unpredictable false triggering within IC201. D607 and D824 ensure that no erratic
negative going pulses are present on the line signal. D813 ensures that the line pulse is pulled up to the
+5V supply when present and to zero when not.
Figure 21 : Sand Castle Pulse Generation Circuit