Okay. For some reason in my car enthusiest life I have never understood about realays... same as I dont grasp what a relay does I also dont understand crossovers either... I'm pretty sure they have the same princeable... I understand that a Relay uses a coil to conduct or product and electrical current that is either larger or smaller than is recieved. Is this correct? I would just like for someone to go over the relay for me before I start using them everywhere....
first what are you planning on using them for,relays can act as nothing more than a switch to remotely turn something on ex) power invertor for a ps2 wired from your ignition to a relay so when the car is started the inverter turns on
well there could be tons of things I could use them for. First off I have the SPAL40 kit for my shaved door handles and I was going to use channels 3-6 for my power windows and channel 7 to pop my trunk. Now I know I need an SPST for my doors and trunk but it says I need an STDT for my windows do to polarity having to alter when in use for positive goes up and negative goes down.... so I must use a reverse polarity connection.
anonther quistion while you all give me some info relays is. Do they all connect say
the 12volt connection at the same spot? how would I know where to connect the grounds powers and input from receiver and output to object being controlled?
Basically it is all inputs and outputs. Think of it like hooking up a home stereo or vcr.
85 and 86 are input sides.
One has to be positive and one has to be negative to make the relay work. If you are hooking up a relay to make windows work lets say hypothetically the spal "brain" shows positive. This means you would ground 85. 86 gets hooked to the spal "brain's" output wire, because when the spal "brain" works it is showing positive.
Now look at the other half of the relay.
If your cars window wire works with negative, then we ground 30 (if it works with positive we would hook it up to 12 volts). 30 is like an input for this half of the relay. The output is 87, so 87 gets hooked up to the window wire in your car.
87a usually is not used because it is always closed. That means that whatever you do to 30, comes through 87a unless the relay is working. The only time we ever use 87a is for starter kills on alarms because when the relay is not working the starter wire goes in 30 and out 87a so you can start the car, but when the alarm is going off the relay is triggered and it switches over to 87 so the starter wire does not get power to start the car.
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a relay works like this, it is a switch that is controlled by a wire other than by a physical switch (button or rocker type, etc).
ok, the 30A in and out are the switched wire. When the power is applied to the low power in and out the switch is closed and power is free to flow through the 30A wires
hmm for some reason I don't think I'm making this simple lol
the wire that turns the relay on and off doesn't have a high current draw. so .1 amp is often enough to turn the relay on. once on, the higher current is free to flow. you can put them in line with headlights to use a higher gauge wire and not need to run the power through the head light switch etc...
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so with 5 connections 2 is used for continues current and 2 is for input and output? so on low in and low out would that be the continues current and if it was used for a possitve cycle it would be connected to a 12volt source?
ive never really got this either, thanks for the imput guys
relays are easy. you should be able to find them on howstuffworks.com that's a real good website, but basically they're used so that a low amperage signal can control a high amperage circuit. the low amperage is used to create an electromagnet (current passing through a coil of wire) and it basicall just pulls a switch in the relay closer to it. that's why you hear them click. when the power is lost to the coil the magnetism is gone and the switch goes back away from the coil to the 'off' position. sorry i don't have any diagrams to post, but the website i listed should have everything you need. hope that helped some.
-john
i understand much better now, even tho i used one to turn my fogs on with my headlights and parking lights!
