All SymNet DSP units are equipped with analog control inputs. These inputscan be utilized in various ways to provide control or trigger events.
Common uses include:
1. Emergency muting via fire alarm relay.
2. Volume control via 10k pot.
3. Source select or preset recall via multi-position switch.
Option number 3 can present a problem called “contact bounce”.
Contact bounce (also called chatter) is a common problem with mechanical
switches and relays. Switch and relay contacts are usually made of springy metals that are forced into contact by an actuator. When the contacts strike together, their momentum and elasticity act together to cause bounce. The result is a rapidly pulsed electric current instead of a clean transition from zero to full current. The effect is usually not important in power circuits, but causes problems in some analog and logic circuits that respond fast enough to misinterpret the on-off pulses as a data stream.