| 摘要 |
PURPOSE:To optionally set up the number of illuminating light emitting elements by connecting the illuminating light emitting elements in series between a power supply means for a room master machine 1 and a camera unit in an entrance slave machine and supplying a constant current from the power supply means for the room master machine through a coaxial cable. CONSTITUTION:The room master machine 1 is constituted of a room master machine monitor part 1 and a room master machine calling part 1b and the monitor part 1a is constituted of a control circuit 8, a constant current circuit 9 to be a power supply means and a TV monitor part 11. The entrance slave machine 2 is constituted of an illuminating light emitting circuit 2a, a camera unit 2b, a speaking/calling means 2e, and a constant current converting circuit 12. The circuit 2a is constituted of parallel connection of infrared light emitting diodes LED1-LEDn to be the illuminating light emitting elements for projecting an object, current setting resistors R1-Rn connected to respective diodes in series, a current adjusting resistor Raj, a protecting diode D1, and a video passing capacitor C1 and a constant current supplied from the circuit 9 to the unit 2b through a CXC is supplied to the circuit 2a.
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