Abstract: An electro-magnetic tacker, which can carry out a limited number of driving strokes when its main switch is actuated, has a staple magazine pivotal between a blocking position and an operating position. In the operating position of the staple magazine, a staple blocking member blocks the front staple located in the staple magazine and, in the blocking position of the staple magazine, releases this staple for entry into a staple output channel. A coupling element connected to the staple magazine has an engagement portion which, in the switched-on position of an actuator element of the main switch, is in engagement with this. In this switched-on position, the actuator element holds the staple magazine in the operating position via the coupling element, so that the tacker can be lifted off from a workpiece, while at the same time the operating position of the staple magazine and the blocking action of the staple blocking member are maintained.

Abstract: A control circuit arrangement for an electromagnetically operated power tool has a primary circuit including a solenoid and a semi-conductor switch, in series, the semi-conductor switch being capable of being triggered into a conducting state upon application of a trigger signal from a trigger control circuit. The trigger control circuit is actuated upon closure of a main trigger switch which is connected in series with the solenoid and the semi-conductor switch in the primary circuit for supplying current to the solenoid. Thus, should the semi-conductor switch fail due to a short-circuit, the power supply is disconnected from the solenoid the moment the operator releases the main trigger switch so protecting the solenoid. The semi-conductor switch is preferably a thyristor. An additional circuit is preferably provided for preventing the thyristor from firing a second time if the main switch remains closed.