Provided is a reliable switch having a contact surface that is prevented from being roughened. To solve the problem, there is provided a switch including a plurality of switching units 2 and 3 each including a fixed electrode and a movable electrode that is disposed to be opposed to the fixed electrode and is closed or opened with respect to the fixed electrode, the switch being characterized in that the switching units 2 and 3 each make or break a current to be applied to the switch, the switching units 2 and 3 are electrically connected in series to each other, and the switching units 2 and 3 are each configured such that a first switching unit 3 is first closed, and then a second switching unit 2 is closed.

An electric power generation control system for a vehicle, which enables generation of electric power by a generator as much as possible while preventing an electrical component from being overheated by power generation by the generator. The electric power generation control system selectively switches a mode of the generator between first and second modes in which an instruction voltage is higher and not higher than an allowable voltage of a wire harness, respectively. A counter value is counted up in the first mode and down in the second mode. When the counter value has reached a higher limit value, the first mode is inhibited and the power generation mode is set to the second mode. This increase the proportion of an execution time period of the first, and accordingly, when a possibility of overheating the wire harness becomes high, the instruction voltage is lowered.

The tendency of a motor-driven actuator 1 driving against a dynamic (non-frictional) load to return upon reaching the limit switch 22 sufficiently to again close the limit switch and create a persistent oscillation at the limit position can be prevented by placing a positive temperature coefficient thermistor across the limit switch involved. Such loads typically arise in actuators having spring-driven return capability, and can also arise when positioning air dampers and other loads where the actuator force is opposed by a spring or gravity.

A control arrangement to prevent or delay the closing of current limiting circuit breaker contacts after opening by repulsion due to a short circuit is disclosed. A first contact arm (10) and a second contact arm (12) are operatively associated with a ratchet (38) for locking the second contact arm (12). A release lever (62) operatable by the first contact arm (10) and the breaker operating mechanism releases the ratchet (38) after a delay period greater than the duration of the short circuit or the operating time of the breaker operating mechanism.

A visco-elastic actuator includes a support section (12) and an actuator section (28). A visco-elastic adhesive (24) serves to hold the actuator in a first state. A spring (40) acts between the sections until the hold of the adhesive (24) is overcome when the actuator is switched to a second state.