Panasonic DP-CL18 Technical Manual page 43

3.5.16. Safety Interlock Circuit and door switches
This printer has 2 safety interlock switches and 2 door switches :
Safety Interlock Switch : LSU Safety Interlock Switch and Front Door & Right Cover Safety Interlock Switch
Door Switch : Toner Cartridge Access Cover Detection Switch and Front Door & Right Cover Open Detection Switch
Safety Interlock Switches and Front Door & Right Cover Open Detection Switch
These switches are located at the right side front chassis frame. When the front door or right cover is opened, these safety
interlock switches are opened, shutting down the +24VA, +24VB and +5VLD powers. Besides, the signal DOPEN ( pin 1 of CN7
) is changed from a low to high because the front door or right cover is opened. This high level DOPEN signal is sent to the
transistor Q21 through IC24 and IC18. The transistor Q21 is turned on, changing this signal from a high to low. IC14 receives
the low level NDOPEN and transmits this information to IC1 (CPU). By receiving this information, IC1 detects that the front door
or right cover is opened, and turns off the laser scanning unit ( LSU ), CMY motor, BK motor, paper pickup motor, high voltage
unit, etc.
Toner Cartridge Access Cover Detection Switch
This switch is located at the left side chassis frame to detect whether the toner cartridge access cover is opened or not. When
the toner cartridge access cover is opened, this switch is opened. This changes the signal TNCDOPEN ( pin 2 of CN11 ) from
a low to high. This high level signal TNCDOPEN is inputted to pin 102 of IC1 (CPU) through IC24, IC20 as high level TCDOPEN
signal. When IC1 receives the high level TCDOPEN, IC1 detects that the toner cartridge access cover is opened, and turns off
the laser scanning unit (LSU), CMY motor, BK motor, paper pickup motor, high voltage unit, etc.
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DP-CL18