NF HVA4321, Instruction Manual

Page: 45 / 152

3.3 Monitor and control signal system
HVA4321
3-13
The delay time from input of the SIGNAL ON/OFF signal to actual ON/OFF is approximately
5
㎲ or less. The delay time from input of other ON/OFF signals to actual ON/OFF is approximately
15
㎲
or less.
The input circuit of the remote control terminal is as follows:
Figure3-19. Remote control input circuit
HIGH VOLTAGE POWER SUPPLY ON/OFF
HIGH VOLTAGE POWER SUPPLY ON/OFF controls ON/OFF of the internal DC high voltage
power supply.
When the HIGH VOLTAGE POWER SUPPLY ON/OFF switch on the front panel is ON and the
HIGH VOLTAGE POWER SUPPLY ON/OFF signal on the back panel is ON, the internal high
voltage DC power supply is ON.
Table3-1. Logic of HIGH VOLTAGE POWER SUPPLY ON/OFF
HIGH VOLTAGE POWER SUPPLY ON/OFF signal in remote control operation
Front panel switch OFF ON
TTL
High
(Approx. 5 V)
Low
(Approx. 0V)
High
(Approx. 5 V)
Low
(Approx. 0 V)
Back panel control
signal
Contact Open Close Open Close
Status of internal high voltage
DC power supply
OFF ON
For HIGH VOLTAGE POWER SUPPLY ON/OFF, the control with external signal is always effective
regardless of "REMOTE" or "LOCAL" settings on the front panel switch.
Therefore, when external control is not used, be sure to short-circuit the control input terminal at the
back with an accompanying shorting plug.
If shorting is not performed, the internal high voltage DC power supply is not ON although HIGH
VOLTAGE POWER SUPPLY ON/OFF switch on the panel is "ON".
+5V +5V
0.0047 µ F
470
10k
74HC14
470