Hioki 3645-20, Instruction Manual

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Set Up
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Counter-electromotive
force protective diode
(3) Example of a Preheat-Signal Connection Circuit
The Preheat signal controls the sensor power on/off.
Connect the 3645-20 to a sensor, power supply, and relay
in the manner illustrated below.
Confirm that the power supply to be used does not exceed
the ratings (30 V, 20 mA max.) of the Preheat signal.
When selecting a relay, note its ratings (voltages and
currents to be imposed on the coil and the relay contacts)
and the polarity of the coil.
When connecting a relay, be aware that the circuit may be
destroyed by a counter-electromotive force generated when
the relay is turned on/off. To prevent such destruction of
the circuit, always insert a protective diode in the manner
illustrated above.