| 摘要 |
PROBLEM TO BE SOLVED: To provide a power line data transmitter for enabling power line communication by superposing a data modulation signal on a DC power supply line by using a simple circuit.SOLUTION: A power source circuit 50 including a transistor Tr1 whose collector receives a DC power source as input and whose base receives constant voltage bias supplies a DC power source to a power source supplying node Na through the transistor Tr1. A modulation circuit 52 operates using the power source supplied from the power source circuit 50 input from the power source supplying node Na, and generates a data modulation signal according to output data of a CPU 41. The data modulation signal leaks in the power source supplying node Na because the node Na is not connected to a capacitor. Voltage between the base and an emitter of the transistor Tr1 changes as potential of the node Na changes; and collector voltage of the transistor Tr1 changes depending on the voltage change. Thereby, a transmission unit 42 can output the data modulation signal to a power source line 13 through the power source circuit 50. |
