UV TRON® DRIVING CIRCUIT

Wednesday, January 21, 2009 · 0 comments

Hamamatsu C3704 series UV TRON driving circuits are low
current consuming, signal processing circuits for the UV TRON,
well known as a high sensitivity ultraviolet detecting tube. The
C3704 series can be operated as a UV sensor by connecting the
UV TRON and applying DC low voltage, as they have both a highvoltage
power supply and a signal processing circuit on the same
printed circuit board.

Since background discharges of the UV TRON caused by natural
excitation lights (such as a cosmic ray, scattered sunlight, etc.)
can be cancelled in the signal processing circuit, the output
signals from the C3704 series can be used without errors.
When the high sensitivity sensor “UV TRON R2868” (sold
separately) is used, the flame from a cigarette lighter (flame
length: 25mm) can be detected even from a distance of more
than 5m.
APPLICATIONS
l Flame detectors for gas and oil lighters
l Fire alarms
l Combustion monitors for burners
l Electric spark detector
l UV photoelectric counter
SPECIFICATIONS
Dimensional outline ..................................................... Figure 1
Weight ................................................................... Approx. 20g
Output signal ....... Open collector Output (50 V, 100 mA Max.)
10 ms width pulse output (Note : 1)
UV TRON supply voltage .......................... DC 350 V (Note : 2)
Quenching time ................................................. Approx. 50 ms
Operating temperature ......................................... -10 to +50°C
(with no condensation)
Suitable UV TRON ............... Low voltage operation UV TRON
(such as R2868)

C3704 C3704-02 C3704-03
Input Voltage 10 to 30 Vdc 5Vdc ± 5% 6 to 9 Vdc
Current consumption 3 mA Max. 300mA Max. 300mA Max.
Note 1: The output pulse width can be extended up to about 100s by adding a
capacitor to the circuit board.
Note 2: Since the output impedance of this power supply is extremely high, an
ordinary voltmeter cannot be used. Use a voltmeter that has an input
impedance of more than 10 GW.
Subject to local technical requirements and regulations, availability of products included in this promotional.

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