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10-5. DEW SENSOR
If excessive moisture or condensation is present inside the machine (an internal humidity of more than 98%) the unit will stop if
running. Until the moisture level decreases only the Eject mode will operate. To sense the humidity, a dew sensor is used. The
sensor is a special variable resistor, which change resistance ambient humidity.
The sensor range in resistance from about 5K ohm at 90% humidity to about 50K ohm at 98% humidity. Normally, the voltage
across the sensor is low because of its low resistance.
But if the moisture condenses inside the unit, the voltage at Dew terminal of SYSTEM CONTROL IC
Dew condition.
Tape
Mode
Power
Dew indication
Cylinder
OUT
Key operation
Cassette in
Power
Dew indication
Cylinder
IN
Key operation
Cassette condition
*1: When the cylinder locks in dew mode, it will be released until dew sensor is turned off.
*2: The keys not relating to the tape running operation are able to used. Switching CH and Audio are effective.
Dew sensor on: During Dew formation is detected and 80 minutes after completion of Dew detection.
Dew sensor off: 80 minutes after completion of Dew detection, because the Dew Sensor dries faster than mechanism due to their
heat capacity.
10-6. SAFETY TIMER
10-6-1. Holding time of special playback and stand-by mode
Special playback and stand-by modes are automatically cancelled after fixed time, in order to protect tape and VCR. The table
below shows VCR mode and its holding time.
VCR Mode
STILL
RSTILL
PAUSE(REC/ADUB/INSERT)
CUE/REV
SLOW/RSLOW
STOP(Stand-by at PLAY position)
10-6-2. Detecting mechanism lock during mode shift
When the mode does not reach aimed position within certain time after the loading motor started, it is recognized as mechanism
lock and mechanism shifts to lock detection function.
Detecting time differs depends on in which timing lock has occurred. However, lock is detected within 5 sec. Maximum.
Mode change and action after lock is detected are as follows.
Mode change
During cassette in
During cassette down
During loading
FF
STOP
Other mode changes
Dew sensor ON
Compulsory Power on
Indicate "d" and "U10"
Rotate forcibly *1
Not possible *2
Immediately a cassette is ejected after it
goes to cassette down position.
Compulsory power on
Indicate "d" and "U10"
Rotating *1
Not possible *2
Shit to DOWN position and waits for
removing dew
Holding time
Approx. 5 sec.
Approx. 2 sec.
Approx. 5 min.
Approx. 10 min.
Approx. 10 min.
Approx. 5 min.
48
Dew sensor OFF
Power off
Normal display
Normal mode
Possible
Possible
Power off
Normal display
Normal mode
Possible
Possible
Mode after holding time has been over
STOP
STILL (PLAY position)
STOP
PLAY
STOP
Stand-by at MID position.
Cylinder stops.
Action and detecting lock
Cassette out
Cassette up
Cassette out
Unloading
Cassette out
l
Stop the loading motor once, and restart it for STOP
direction after 5 sec.
l
P-OFF when the second lock is detected.
P-OFF immediately
increases to indicate
the
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