drycontact
A dry contact, also known as a potential-free contact or dry-switch contact, is a type of electrical contact whose terminals do not carry a supply voltage or signal within the device that contains the contact. The device only provides a switch closure or opening; the external circuitry supplies the voltage and current to be controlled. The term contrasts with wet contacts, where the device provides power or a signal to the circuit contacted.
Dry contacts are typically realized through mechanical switches or relays with isolated contacts, and sometimes through
Applications include alarm and security systems, building automation, PLC inputs, process control, and safety interlocks. Dry
Key considerations include the external circuit’s voltage and current limits, contact ratings, and the effects of