| 摘要 |
PROBLEM TO BE SOLVED: To provide a data signal reception circuit for illumination control that is adaptable to control signals different in limit value of input current and transmission speed by the same circuit.SOLUTION: A rectifying unit 20 subjects a data signal for illumination control to half-wave rectification. Constant current circuits 30, 40 are connected in series to the input side of photo-couplers 31, 41 which are supplied with the data signal for illumination control subjected to half-wave rectification by the rectifying unit 20. Input current to the photo-couplers 31, 41 is limited in connection with a first control signal having current value limit of a control signal. Pull-up resistors 33, 43 are connected to the output sides of the photo-couplers 31, 41. A switching unit 23 switches the circuit configuration so that at least one of the resistance value of the constant current circuit 30, 40 and the resistance value of the pull-up resistor 33, 43 decreases when the data signal is a second control signal which has no current value restriction to the control signal and also has a higher transmission speed than the first control signal. |
