Industry-standard ISO mini relays are common and affordable. A 12-volt, NO/NC, SPDT version like this one (Hella PN 007794301, $6.38 at Summit) can control both normally open and normally closed ...

An ISO relay is one which adheres to a standard pattern for its electrical terminals that has been spelled out by the International Standards Organization.

The vendor offers a complete range of 25 Control Units (also called “Safety Relays”) that are certified according to the new Machine Directive EN ISO 13849-1, to take effect in Europe on Dec. 30, 2009 ...

How to Lockup a 700R4 Torque Converter Clutch Without a Computer Using a Manual Switch and ISO Relay.

We believe Semtech’s Neo-Iso platform will become the standard for multiple systems.” The new Neo-Iso SSR, TS13501, supports DC and AC systems and is priced at $0.62 in volumes of 10,000 units.