Electromagnetic relays can be put to some quite clever and complex applications when linked up to perform logical operations based on certain inputs for example latching a 12v output on and off from a momentary input flashing alternative left and right lights etc. For example the six gray boxes in this photo of a ford windstar fuse box are all relays.
Autoswitch Relay Basics For The Novice
What does a 12v relay do. So how much voltage does a 12v relay need to work. Another name for this is pick up voltage. General purpose relays operate with ac or dc current at common voltages such as 12v 24v 48v 120v and 230v and they can control currents ranging from 2a 30a. This is a relay from an electronic hot water immersion heater programmer. They are also common in cars where the 12v supply voltage means that just about everything needs a large amount of current. The second 12 volt positive lead from the on off switch can connect to an ignition activated system to give you manual control.
As you can see from the snippet of the datasheet there is a term pull in voltage. Connect the ground wire from the relay to the high beam positive wire so the fog lights will turn off when the highs are on. In places where a large. These relays are economical easy to replace and allow a wide range of switch configuration. Pull in voltage is the voltage required for the relay coil to energize and build enough strength the overcome the. Thinner cables can be used to connect the control switch to the relay thereby saving weight space and cost.
Connect the 12 volt positive lead to the positive wire on the parking lights. 12v dc relay switches are the best solution for full voltage applications as they allow a low current flow circuit to control a high current flow circuit like a vehicles horn headlights auxiliary lamps fan motors blower motors and countless pieces of equipment existing on vehicles today. A solid state relay uses a thyristor triac or other solid state switching device activated by the control signal to switch the controlled load instead of a solenoid. Relays allow a low current circuit to control one or more higher current circuits. Relays provide these benefits. Another important function of the relay is quick switching off 005sec max.
Relays are quite common in home appliances where there is an electronic control turning on something like a motor or a light. General purpose relays are electromechanical switches usually operated by a magnetic coil. How is a relay designed. What is a pull in voltage. An optocoupler a light emitting diode led coupled with a photo transistor can be used to isolate control and controlled. In this relay when a current flows through the coil it turns it into an electromagnet.
Lets start by looking at a datasheet for an ad pr40 1c 12d 12v relay which is an open style power relay. A datasheet is a document with detailed specifications of a component. A solid state relay ssr is a solid state electronic component that provides a function similar to an electromechanical relay but does not have any moving components increasing long term reliability. In later model cars manufacturers have started combining relay panels into the fuse box to make maintenance easier. The magnet pushes a switch to the left forcing the spring contacts together and completing the circuit theyre attached to. To switch on a 12v 60100 watt halogen lamp a typical 12v relay allows a voltage drop of only 002v and the coil current is only 2 milliamps.
Gallery of What Does A 12v Relay Do
