| 摘要 |
PURPOSE: To provide a set value current-feeding circuit which gives a correct set current value and shows a fast response. CONSTITUTION: The circuit has a current-amplifying part Q1, a current-detecting resistor Rs for measuring a value of a current Iout and a current-limiting part 30 for controlling a voltage generated in the Rs to be not higher than a fixed value. The current-amplifying part Q1 has an input of a voltage signal V1 output from a signal-outputting part 10 to a base terminal, connects a collector terminal to a power source±Vp and outputs a current corresponding to a signal impressed to the base terminal from an emitter terminal. The circuit feeds an output signal Vout to a load via the resistor Rs. The current-limiting part 30 is provided with a constant current element D1 for feeding a constant current from the power source, a Zener diode D2 generating a reference voltage, and a switch element D3 having one end connected to a common contact between the constant current element D1 and Zener diode D2 and the other end connected to an output terminal of the signal-outputting part 10. When the voltage generated at the current-detecting resistor Rs exceeds a value determined by the reference voltage, the switch element D3 is turned ON to feed a set value current to the load.
|
