| 摘要 |
PURPOSE:To reduce the cost and power consumption of the titled circuit irrespectively of the number of light emitting elements being increased, by providing plural light emitting elements connected in series, a driving circuit which supplies a constant current to the series circuit of light emitting elements, a control section which controls the driving circuit, the 1st battery power source, and 2nd battery power sources. CONSTITUTION:Light emission diodes 21, 22, and 23 are connected in series. A constant-current circuit 10 and the series circuit of a resistance 11 and the emitter and collector of a transistor 12 constitute an electricity supplying path to the series circuit of the light emission diodes 21, 22, and 23. Then a driving circuit 1 is connected with the series circuit of the 1st battery power source B1 and 2nd battery power source B2 and, at the same time, another driving circuit 2 is connected with 2nd battery power source B2. Therefore, even though the constant-current circuit 10 has only one output system of a constant current i0, namely, only one transistor, the circuit 10 can supply the working current i0 to each light emission diode 21, 22, and 23. |
