Automotive-style miniature relay, dust cover is taken off. A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays. Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal.
https://en.wikipedia.org/wiki/Relay
Inside a relay. This is what the inside of an ISO mini relay looks like: A copper coil around an iron core (the electromagnet) is held in a frame or 'yoke' from which an armature is hinged. One end of the armature is connected to a tension spring which pulls the other end of the armature up.
http://www.12voltplanet.co.uk/relay-guide.html
ISO defines mini relays with the control circuit connected to pin 86 and pin 85, and the load circuit connected to pin 30 and pin 87 or 87a. There will be only 1 second load pin, 87 or 87a, not both. Determine that the relay is an ISO micro type. The ISO defines this type of relay as 1 inch (2.5 cm) by 1 inch (2.5 cm) by 0.5 inches (25.4 mm by 25.4 mm by 12.7 mm). An ISO micro relay has the control circuit connected to pin 86 and pin 85, and the load circuit connected to pin 30 and pin 87 or 87a.
http://www.wikihow.com/Test-a-Four-Terminal-Relay
Many of the electromechanical relays used in automotive applications are termed . 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. Generally speaking, types of ISO relay terminal patterns include Super ISO, ISO 280, Mini 280 ISO and Micro 280 ISO. They are widely used in both Europe and the U.S.
http://www.machinedesign.com/archive/iso-relays
Relay symbols and device numbers; selection from IEC 617-, IEEE C37.2-1991. and IEEE C37.2-1979. 1MRK 590 006-BEN. Page 7. 30 Annunciator relay is a nonautomati-. cally reset device that gives a number. of separate visual indications upon the.
https://library.e.abb.com/public/c1256d32004634bac1256e19006fe686/1MRK590006-BEN_en_Relay_symbols_and_their_device_numbers.pdf
Steps. 1  1. Find and remove the relay. The relay should not be tested while it is connected to the circuit. 2  2. Find the relay characteristics. The relay will have 4 pins; 2 will connect to the control circuit and 2 will connect to the high power load. 3  3. Confirm the integrity of the relay load connections.
http://www.wikihow.com/Test-a-Four-Terminal-Relay
Page 8. IEEE device numbers. and functionsand functions (cont’d) (cont’d) 46 Reverse-phase or phase-balance. current relay is a relay that functions. when the polyphase currents are of. reverse phase sequence or when the. polyphase currents are unbalanced or.
https://library.e.abb.com/public/c1256d32004634bac1256e19006fe686/1MRK590006-BEN_en_Relay_symbols_and_their_device_numbers.pdf
Car Relays. A car relay is a electro-magnetic switch that uses a small amount of current to control a larger amount of current. How they work is by a wire wound magnetic coil that when excited by a electric current, moves a mechanical spring contact inside the relay, completing a circuit. Car relays are usually controlled by another switch such as your car horn button, headlight switch circuit or power window / door lock switches.
http://www.accessconnect.com/car_relays.htm
ISO mini relays with two circuits, one of which is closed when the relay is at rest and the other which is closed when the relay is energised, have 5 pins on the body and are referred to as changeover relays. These have two contacts connected to a common terminal.
http://www.12voltplanet.co.uk/relay-guide.html
Page 6. IEEE device numbers. and functionsand functions (cont’d) (cont’d) 15 Speed or frequency matching. device functions to match and hold. the speed or the frequency of a. machine or of a system equal to, or. approximately equal to, that of another.
https://library.e.abb.com/public/c1256d32004634bac1256e19006fe686/1MRK590006-BEN_en_Relay_symbols_and_their_device_numbers.pdf
what is an iso relay
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.