2.3 Overvoltage protection
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The overvoltage protection circuit is built-in and comes into effect
at 115 - 140% of the rated voltage. The DC input voltage should
be shut down if overvoltage protection is in operation. The mini-
mum interval of DC recycling for recovery 2 to 3 minutes ( ).
The recovery time depends on input voltage.
By detecting overvoltage condition bV and -V, overvoltage
protection circuit comes into effect at 115 - 140% of the rated
voltage.The DC input voltage should be shut down if overvoltage
protection is in operation. The minimum interval of DC recycling
for recovery 2 to 3 minutes ( ).
The recovery time depends on input voltage.
Please note that unit's internal components may be damaged if
excessive voltage (over rated voltage) is applied to output termi-
nal of power supply. This could happen when the customer tests
the overvoltage performance of the unit.
The output voltage is adjustable by external potentiometer.
When the output voltage adjustment is not used, open the TRM
pin.
The over voltage protection circuit comes into effect when the out-
put voltage is set too high.
Output voltage is increased by turning potentiometer clockwise
and is decreased by turning potentiometer counterclockwise.
The wiring to the potentiometer should be as short as possible
and connected to the remote sensing pins (+S and -S).
The temperature coefficient varies depending on the type of re-
sistor and potentiometer.
It is recommended that the following types be used.
Resistor ...........Metal film type. coefficient of less than ±100ppm/
Potentiometer..Cermet type, coefficient of less than ±300ppm/
2.4 Adjustable voltage range
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Single Output
Multiple Output
Remarks:
2.5 Remote ON/OFF
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The ground terminal of remote ON/OFF circuit is connected with
-V input terminal.
Between RC and -V input: Output voltage is ON at ”Low” level or
short circuit (0 - 1.2V)
Between RC and -V input: Output voltage is OFF at ”High” level
or open circuit (2.4 - 5.5V)
(Connection example)
ZU/ZT-41
ZU15 ZU25
Fig.2.1 Overcurrent protection characteristics
Fig.2.2 Connection devices outside the power supply
Table 2.1 Devices outside the power supply (Adjustable ±5%)
No.
Output
voltage
1
2
3
4
5
3V
5V
12V
±12V
±15V
VR
1K
1K
5K
5K
5K
R1
470
100
270
10K
10K
The constant value of devices outside the power supply (Unit: )
R2
150
270
2.7K
3.9K
2.7K
or
or
Transistor
IC
Relay
When RC terminal is ”Low” level, fan out current is 1mA typ.
When Vcc is applied, use 5V
Vcc
24V. When remote ON/OFF
function is not used, please short between RC and -V input.
2.6 Isolation
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For a receiving inspection, such as Hi-Pot test, gradually increase
(decrease) the voltage for the start (shut down). Avoid using Hi-
Pot tester with the timer because it may generate voltage a few
times higher than the applied voltage, at ON/OFF of a timer.
ZU/ZT
Instruction
anual
M
DC-DC Converters PCB Mount type
