Metz mecablitz 40 MZ-2 Servicehandbuch Seite 30

Technik und Service
Technology and Service
the oscillator are activated. The appropriate
Supply voltages:
Supply voltages for IC301:
Supply voltages for the
periphery:
Reset:
As soon as batteries are inserted, IC502 is supplied with voltage via fuse resistor R501, fuse Si501 and
diode D513. In addition to the regulated 5V voltage at pin 1, IC502 generates the reset signal at pin
4. IC301 is reset with a low signal at pin 41.
Waking up:
If the operating mode switch is in the position "OFF", or if the automatic power-off function has
been triggered, IC301 is in its so-called "sleep" mode, and the converter stages and the periphery
of IC301 are switched off. In this mode, the current consumption of the mecablitz is so low that it
cannot be measured.
Actuating the main switch or pressing the +/- buttons (with the main switch set to AUTO OFF)
generates a positive pulse. In the case of the main switch, this pulse is generated by means of
wiper contacts between the various switch positions. This positive pulse passes through C302 to
C303 and R321, where a positive squarewave pulse is generated. This pulse then "wakes up" IC301
via pin 42.
mecablitz 40 MZ-2
voltages and the oscillator. All data in the RAM are
retained! IC301 is in "sleep" mode and can be
woken only via pin 42 or by a reset.
- If the main switch is ON (and "AUTO OFF" has not yet
occurred or if LOCK is active), the auxiliary voltages
- +5V (from IC502) at pin 33
- ground at pin 15
- ground for the LC display at pin 10
- reference voltage for A/D converter (clocked 5V
voltage from Tr307) at pin 21
- ground for A/D converter at pin 20
- 5V from voltage regulator IC502:
various components which do not consume current
while the flashgun is switched off
- clocked 5V voltage from Tr307 via pin 11 and Tr307:
reference voltage for A/D converter and voltage
divider for buttons
- clocked 5V voltage from Tr308 via pin 11 and Tr308:
supply voltage for EEPROM, IC503 and Schmitt
trigger Tr511/Tr512; various pull-up resistors
- battery voltage via fuse Si501:
LEDs except D304, supply voltage for power zoom
control
- switched battery voltage from Tr504:
LED D304
program loop is now executed.
Seite: 30
Page: 30
ENGLISH
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