Understanding Form A, Form B and Form C Contact arrangements.
"Form A refers to a Contact configuration term for relays, Form A refers to a Single Pole-Single Throw normally open contact. "1 Form A" means there is one Form A contact in the relay, "2 Form A" means there are two "Form A contacts" in the relay, so on and so forth.
Form B refers to a normally closed Single Pole-Single Throw contact arrangement in a relay. This means that it stays in a closed (off) state without you driving the relay to operate. "1 Form B" means there is one "Form B contact," "2 Form B" means there are two "Form B contacts" in the relay, so on and so forth.
Form C refers to a Single Pole-Double Throw (SPDT) contact. This means that there is one common point connected to one normally open-end and another normally closed contact. "2 Form C" refers to two "Form C contacts," so on and so forth.
Form A Normally Open is the most common configuration for relays. The relay acts as a switch and breaks the circuit. Then a small control voltage or current is applied to close the relay, therefore connecting the circuit.
Bright Toward offers a wide range of Form A Normally Open Relays, from Optically-coupled MOSFET Relays, Reed Relays, Multi-Channel Reed Relays to our six channel MEMS Switch. To search for Form A normally open relays in our fleet, please select your desired "Contact Form" in "multiple search." Or tell us your requirements through below form.