| 摘要 |
PURPOSE:To provide a luminous diode a constant-voltage circuit for supplying a driving current thereto, and temperature compensating signal generating means in a luminous source thereby to stabilize a luminous source for the photo-fiber communication. CONSTITUTION:A constant-voltage circuit consisting of an operational amplifier 22, a transistor 23 and a resistor 24 is connected between a Si diode 21 and an LED element 25. If the circuit is constituted in this manner, when the temperature is constant, the terminal voltage of the diode 21 becomes constant, and a constant current flowing through the LED element 25, and the output photo-power does not vary even after the lapse of time. However, when the temperature has varied, the terminal voltage of the diode 21 varies, and the current flowing through the LED element 25 tends to vary. However, since the amplifier 22, transistor 23 and resistor 24 are added, the output power of the LED element 25 becomes constant, complicate and precious parts such as a photo branch path and the like become unnecessary. |
