Nikon SB-800 Repair Manual page 47

Hide thumbs Also See for SB-800:

Table of Contents

・Buzzer drive circuit:

This is the control circuit for sounding an external buzzer. The buzzer tone, pattern, etc are controled by the CPU.

・CPU:

This controls, etc the following: data correspondence control with camera via the custom IC; data communication control

for setting data to the custom IC; reading of switches; power-supply control; AF assist illuminator control; LCD indications;

motor drive circuit; voltage detection of the main condenser; turning ready-light to ON/OFF; EEPROM control; turning EL

to ON/OFF; slave circuit control, etc.

・Ready light:

This lights up by the CPU when the voltage reaches the ready-light illumination. The CPU judges the charging voltage

by A/D conversion of the voltage output from the voltage detection circuit. At the same time, signals to illuminate the

ready-light in the camera finder are sent to the custom IC via 5-bit data communications.

・Slave circuit:

This performs real-time controls by detecting flash-start of other speedlights, outputing flash-start signal to TG circuit,

detecting flash-stop of the speedlights, and outputing flash-stop signal.

・EEPROM:

This memorizes information such as status set by the switch input circuit, information necessary for the metering circuit, set

value of the timer circuit, etc.

・LCD:

This indicates the flash control mode, TTL exposure compensation value, TTL underexposure ratio, zoom value, manual

flash output, etc. This adopts the dot matrix type (132 X 64 dots) of STN type, and the LCD driver is mounted on the LCD

glass.

・EL:

This is the back light to illuminate the LCD. This is automatically turned ON when the switch is operated, then after a

certain time passed, automatically turned OFF.

・Motor drive circuit:

This sets the illumination angle of the flash unit. The flash unit is set in position under command of the CPU.

・Switch input circuit:

This detects ON/OFF of the push switch on the backside of SB-800 and the mechanically required bounce position, the

status of the wide panel setting, etc.

・Shoe contacts:

This has 5 contacts (CX, CRY, CSTP, CSP, GND) and connects electcially to camera. This is also the signal contacts to

communicate data with camera.

- E 4 ･ SB-800 -

FSA03501-R.3613.A

Table of Contents