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DESCRIPTION
OF MAIN
CIRCUIT
OPERATION
' MODEL RAS-32CNH1
1. Reset Circuit
30V
ZD201
Q202
Normal: Hi
Reset
:Lo
Q201
R204 R206
R203
Micro computer
Fig. 1-1
Voltage
SOV b ---- rrr
rn fr rrr rrr rr rr
ee
pee
eee
5V DC Line
BV | ---------
Base of Q201
Power
is ON
BV | ------l------
Collector of Q202
Fig. 1-2
® The reset circuit initializes the program when power is supplied or power is restored following a power
failure.
@ RESET
"Lo" or SET "Hi" activates the micro computer.
@ Fig.1-2 shows the waveforms in each circuit when power is ON and OFF.
@ When
power is supplied, the voltages on the 39V and 5V DC lines rise, and when the 39V DC line
becomes approx. 30V, ZD201
turns on and the voltage at the base of Q201
rises to turn Q201
on.
Since the collector of Q201
goes "Lo" at this time, Q202 turns on and the reset input of the micro
computer goes "Hi".
The 5V DC line has already been 5V at this time and the micro computer starts
Operation.
@ When
power is OFF, the voltage on the 39V DC line drops, and when
it is approx. 30V, ZD201
turns off,
Q201
and @202 turn off, and the reset input of the micro computer goes "Lo" to reset it.
—~94-—
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