The best definition I could find online is:
These handy boards provide a simple method to interface a low level control output from a control system such as the FSR Flex Gpio ports to higher level loads such as a low voltage screen controller. They can also be used to reverse control output logic if necessary
**can someone break this down in layman’s terms?**
In: Technology
Not sure of the exact unit you’re using, but I’ll try for generic relay operations.
As noted by another commenter, a relay is just a form of switch. Your car has a multitude of relays, which are used to avoid high amperage circuits from being run into the switches in the car.
Example – headlights…a car’s headlights can draw between 8-10 amps (highbeams on older vehicles). That sort of load would require a heavy gauge wire to operate. It is inconvenient and unsafe to try and route a heavy wire from the fuse block all the way to the switch and then back out to the headlights – especially if the switch is on the turn signal lever.
Instead, they run a small gauge wire through the switch, which only needs to carry a load of about 0.02 amps – this circuit will operate a small electromagnetic coil inside the relay. When that coil is activated, it closes a set of spring loaded contacts inside the relay. These contacts are what carries the higher amperage load of the lights. The relay can be mounted under the hood, between the battery and lights – much shorter run heavy wire.
Standard “Bosch style” relays will also have numbers to designate the terminals:
85 – power to electromagnetic coil
86 – ground for coil
30 – power for heavy load
87 – power to heavy load (normally open contact, only sends power when coil activated)
87a – power to heavy load (normally closed contact, only sends power when coil deactivated)
Just to confuse things, some controllers don’t send power to the coil, but instead activate the ground side of it.
Do a search for something like “fog light relay circuit” for visual examples.
We also use relays in industrial applications – can use a 24VDC signal to activate the coil, while the heavy load may be a 480VAC circuit.
Latest Answers