Campbell Scientific CS125 Present Weather Sensor - Manual (Page 51)

A-1
Appendix A. CS125 block diagram
850nm
Emitter
Photo-
detector
Transimpedance
amplifier
Power level +
Driver circuitry
Emitter power
feedback
Dirty window
detector
Dirty window
detector
Amplifier
and filter
Amplifier
and filter
Second stage
amplifiers and filters
14-bit Analogue to
digital converter
MCU
(Micro controller unit)
Hood heater
drive
Low noise PSU Two 5V user
alarm outputs
RS232 or RS485
serial
communications
24V
AC/DC
12V DC
Hood
temperature