| 摘要 |
PURPOSE:To ensure power check even in a transmitter with small power by using a light emitting diode capable of light emitting even with a small power as a power sensor and weighting a resistance value to control the lighting of plural light emitting diodes. CONSTITUTION:A current limiting resistor acts so as to increase the resistance of a resistor 3a connecting to a red light emitting diode 41 and decrease the resistance of a resistor 3b connecting to a green light emitting diode 42. A high frequency power outputted from a transmission output terminal 2 of a transmitter 1 is consumed by current limiting resistors 3a, 3b and much high frequency current flows to the green light emitting diode 42 connecting to the current limiting resistor 3b with a low resistance and the light emitting diode is lit when the current reaches a trigger current of the light emitting diode. Thus, the green light emitting diode 42 is lit while the high frequency power is low and the red light emitting diode 41 is also lit when the high frequency power is increase. |
