Abstract: A shield member is placed in a case, and connector pins extend through respective through capacitors and are soldered to the shield member. A core is inserted in the case, and has an engaging member engaging an upstanding portion of the case, the core having a gap fitted over a ridge on the case. A printed-circuit board has positioning holes fitted over pins on the core. The connector pins have respective upper ends inserted through and soldered to through holes defined in the printed-circuit board. Attachment holes defined in the printed-circuit board are held in registry with threaded holes defined in an upper end of the upstanding portion of the case, and the printed-circuit board is fastened to the upstanding portion by screws threaded through the attachment holes into the threaded holes. A shield cover is bent over into alignment with an upper edge of the shield member, and teeth on the shield member are bent inwardly onto and soldered or spot-welded to the shield cover.

Abstract: A Hall-effect device for detecting a magnetic flux intensity has a pair of input terminals connected respectively to a constant-voltage regulated power supply and an FET. The FET has a gate connected to the output terminal of an operational amplifier. One of the input terminals of the operational amplifier is connected to the junction between a variable resistor and a temperature-dependent variable resistor which jointly serve as a voltage divider. The temperature-dependent variable resistor has a temperature characteristic of resistance which is opposite to the temperature characteristic of sensitivity of the Hall-effect device. When the ambient temperature varies, the sensitivity of the Hall-effect device also varies, and so does the resistance of the temperature-dependent variable resistor. The divided voltage applied from the voltage divider to the operational amplifier drops, lowering the voltage applied to the gate of the FET.