| 摘要 |
PURPOSE: To prevent induction of spurious voltage and power loss at the stationary time of an electromagnetic actuator by turning on a first transistor(Tr) in a transistor Tr bridge on and operating a second Tr in linear mode. CONSTITUTION: The coil 1 of an electromagnetic actuator is connected in series with a resistor 2 and connected with a Tr bridge 3 comprising a combination of Tr 6, 10, 14, 17. The resistor 2 is connected, at the opposite ends thereof, with analog comparators 22. When a reference voltage Vc is fed to an input 25, an error voltage from a subtractor 24 is outputted through an amplifier 27 to a point 28. When the error voltage is positive, the Tr 6, 17 are turned off while the Tr 10 is turned on and the Tr 14 operates in linear mode in proportion to the error voltage. When the error voltage is negative, the Tr 10, 14 are turned off while the Tr 6 is turned on and the Tr 17 operates in linear mode in proportion to the error voltage. When the error voltage is 0, current flowing through the coil 1 goes 0. |
