| 摘要 |
FIELD: check point equipment, in particular, token machines in metro. SUBSTANCE: device has light source, which is connected to controlled direct current power supply, photodetector which is connected to threshold circuit for signal generation, additional photodetector and signal for comparison of its signal to signal level of reference power supply, which output controls anode current of light source. EFFECT: increased validity of checking. 1 dwgn
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