Applications
Dip switches were used extensively in ISA architecture of PC expansion cards to select IRQs and memory addresses. They were also often used on arcade games in the 1980s and early 1990s to store settings before the advent of cheaper, battery-backed RAM, and were very commonly used to set security codes on garage door openers as well as on some early cordless phones. This design, which used up to 12 switches in a group, was used to avoid RF interference from other nearby door opener remotes or other devices. Current garage door openers use rolling code systems for better security.
These type of switches were used on early video cards for early computers to facilitate compatibility with other video standards. For example, CGA cards allowed for MDA compatibility.
Recently (since the late 1990s), dip switches have become less common in consumer electronics. Reasons include the trend toward smaller products, the demand for easier configuration through software menus, and the falling price of non-volatile memory. However, dip switches are still widely used in industrial equipment because they are inexpensive and easy to incorporate into circuit designs, and because they allow settings to be checked at a glance without powering the system on.
Dip switches are still used in some remote controls to prevent interference; for example, to control a ceiling fan (and its light fixture) that was retrofitted to a single-circuit junction box. The dip switches set a different radio frequency for each transmitter/receiver pair, so that multiple units can be installed in different rooms of the same house, or different units of the same apartment building, without unintentionally controlling each other.
Rotary switches are also used in X10 home automation to select house and unit numbers. Rotary switches are also used in some radio transmitters (particularly VHF and FM broadcast) to select the DC bias used to set the voltage-controlled oscillator, which determines the center frequency of the carrier wave output.
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