Panasonic RC-Q500 Service Manual page 10

Pin Mark
No.
1~13 Segment
signal output
14 Colon output — Not used
15 Vss
16 CR OSC
17 SPEED/
POWER
18 DC OUTPUT
19,20 19...ALARM1
OUTPUT
20...ALARM2
OUTPUT
21 ALARM
DISPLAY
22 TIME SET
INPUT
I/ Function
O
O Output terminals for
segment drive signals
I Power supply input
O Outputs an oscillating
signal source necessary
for the time base during
back-up operation and
operates the time counter.
Also functions as an alarm
tone signal (OSC
frequency = 2.4 kHz)
I Vss for AC operation.
O When radio on signal is
received or generates at
IC1, this pin will send a
high signal to the radio +B
voltage control circuit (Q1).
O Outputs an alarm signal
("H" level) when alarm
time matches the current
time. When this pin is
momentarily grounded
(VDD) the alarm output
stops.
I When a high signal is
applied to this pin, the
contents of alarm 2 is
displayed and the setting
input is enabled. When a
low signal is applied, the
above applies instead to
alarm 1.
I Applying a signal to this
pin causes the value of the
current time of alarm time
to increment. If the input
voltage is Vss, the time
decreases. If the input
voltage is VDD, the time
increases. If the input
voltage is a pulse
signal(caused by
depressing the switched
S10), the speed increases.