Cam timer

A drum switch (English: cam switch or cam controller), also known as programmer, is an electro -mechanical device that serves to open electrical switch in a given time overrun and close. Here, a motor drives at a low speed of a shaft arranged on the cams. The cams operate the switches. Therefore, it is also the name camshaft gear.

This compact and cost-effective component is used for the " automation " of machines. A typical example is the household washing machine. The type of control can be described as " flow control ".

Today, the drum counter are increasingly being replaced by electronic circuits, as when additional tasks such as reports or alerts are required, the switch has disadvantages drum in comparison to the electronic solutions. In addition, electronic solutions are of a purely mechanical usually cheaper today.

If you replace the motor by a manual drive and defines various positions then becomes like a mode selector switch. Thus, for example, then the drive switch on a streetcar, with which the speed is controlled look.

Musical Instruments

Widely used are drum switch in music boxes and other mechanical music machines. It speaks generally of rolling pin. Here any electrical switches but reeds are actuated.