BCD rotary switch move in a circle and can stop in several positions. A rotary switch is used to control many electrical circuits with a single switch and can be designed to have many contacts happening at once in a single switch position. We offer 3-position rotary switches and 2-position rotary switches. These are often used when more than two positions are needed, such as in a three-speed fan or a CB radio that has multiple channels. Our rotary switches are engineered for use in harsh environments. These are used for control panels on industrial and plant equipment, radio frequency selection, voice and data communication, entertainment systems, automatic climate control, and in heavy-duty vehicles for commercial transportation, construction, and agriculture.
BCD rotary switch:
Binary-coded decimal (thumb wheel) is not only relatively expensive but is also often not available to the desired specification. A good alternative is shown in the present circuit that uses generally easily available components and a 12-position rotary switch (the most popular type), of which two positions are disabled. The terminals of the switch are connected to the inputs of a priority encoder. IC1. When an input goes low, the IC puts the number of that input as an inverted BCD code at the output. The four XOR gates enable the inverted code to be inverted again into a standard BCD code.
This operation is effected with link JP1: in position P, the output code carries the standard BCD code, and in position N, the inverted BCD code.
The circuit is powered by 3–18 V (because CMOS ICs are used). The use of a 5 V source enables LS. TTL, HC, and HCT inputs are also to be connected to the switch. The circuit draws a current of only about 200 μA.
|Contact Current Rating
|150 mA @ 60 V dc
|Number of Switch Positions
|Number of Contacts
|Angle of Throw
|Maximum Operating Temperature
|Minimum Operating Temperature