| 摘要 |
PURPOSE:To prevent danger and excessive temperature rise at an installation part by excessive output of ultrasonic waves by monitoring a current value of a changeable voltage output, and keeping the output current constant to be a predetermined current without having a current more than required added to a load. CONSTITUTION:A voltage to be given to an ultrasonic diagnosing device is set at a D/A converter 3 based on digital data for an output voltage of a power source device. In the meanwhile, a maximum tolerable current to be supplied to a load is set at a D/A converter 4 based on digital data. Voltage setting data are outputted from the D/A converter 3 and inputted to a positive terminal of an operation amplifier 5. An output voltage separated by partial voltage resistances R1, R2 is inputted to a negative terminal of the operation amplifier 5, and the differential output is applied to the base of a transistor 2. An inner resistance of the transistor 2 is controlled by a base voltage of the output of the operation amplifier 5, so as output DC voltage of a rectifying circuit 1 is dropped by the inner resistance to be settled at a set voltage. |
