Understanding Form A, Form B and Form C Contact arrangements. - FAQs | Bright Toward Industrial Co., LTD.

Manufacturer of Opto-MOSFET Solid State Relays, Reed Relays, and RF MEMS Switches. We mainly serve the Semiconductor Testing, ATE, BMS (Battery Management Systems), industrial machinery and Electric Vehicle industries.

Understanding Form A, Form B and Form C Contact arrangements.

Understanding Form A, Form B and Form C Contact arrangements.

Understanding Form A, Form B and Form C Contact arrangements.
Understanding Form A, Form B and Form C Contact arrangements.

Understanding Form A, Form B and Form C Contact arrangements.

Form A Normally Open

“Form A” is a Contact configuration term for relays. It 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 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 provides a wide range of contact forms and multi-channel 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 click the "MULTIPLE SEARCH" on the upper right of the page and choose the [CONTACT FORM] as you need. Or use the below form to tell us your need, and our professional team will contact you with the suggestion soon.

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.

Form B Normally Close

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 SPDT, Normally Open + Normally Close

Form C refers to a Single Pole-Double Throw (SPDT) contact, which 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) Opto-MOSFET Relays:
  • 26 Series: Load Voltage 40V / Load Current 3.5A
  • 28 Series: Load Voltage 40V / Load Current 4.5A
  • 45 Series: Load Voltage 60V / Load Current 200mA
  • 30 Series: Load Voltage 400V / Load Current 120mA
  • 38 Series: Load Voltage 600V / Load Current 80mA
  • 40 Series: Load Voltage 1500V / Load Current 45mA
  • 58 Series: Load Voltage 1800V / Load Current 30mA
Miniature Reed Relays With Their Respective Contact Arrangments:
  • SIP Series (Load Voltage 150V / Load Current 1.75A): 1 Form A (SPST, Normally Open), 1 From B (SPST, Normally Close)
  • MSIP Series (Load Voltage 200V / Load Current 1.5A): 1 Form A (SPST, Normally Open), 2 Form A (SPDT, Normally Open)
  • DIP Series (Load Voltage 100V/Load Current 1A): 1 Form A (SPST, Normally Open), 2 Form A (Normally Open), 1 Form B (SPST, Normally Close), 1 Form C (SPDT, Normally Open/Normally Close)
  • VSIP (Load Voltage 230V/Load Current 1A) Switch vertically packaged: 1 Form A (SPST, Normally Open)
  • VN Series (Load Voltage 150V/Load Current 1A) Switch vertically packaged with Multi-Channel: 1 Form A (SPST, Normally Open), 2 Form A (SPDT, Normally Open), 4 Form A (SP4T, Normally Open)
  • BU Series (DC to 6GHz Load Voltage 210V/Load Current 1A): 1 Form A (SPST, Normally Open), 1 Form C (SPDT, Normally Open/Normally Close)
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B.T - A manufacturer of Solid State Relays, Reed Relays and MEMS Switches.

Located in Taiwan since 1988, Bright Toward Industrial Co., LTD. is a relay supplier and manufacturer. Main products, including Opto-MOSFET Relays, Opto-SiC MOSFET Relays, Solid State Relays, Reed Relays, And RF MEMS Switches, etc.

B.T supplies relays to the world's semiconductor and automotive industries for over three decades and has long term long-term partnerships with OKITA Works based in Japan; Menlo Microsystems based in California; JEL Systems based in Japan and Teledyne Relays and Coax Switches based in California. Mainly serve the Semiconductor Testing, ATE, BMS (Battery Management Systems), industrial machinery and Electric Vehicle industries.

B.T has been offering customers high-quality Opto-MOSFET and Opto-SiC MOSFET relays since 1988, both with advanced technology and 30 years of experience, B.T ensures each customer's demands are met.