choosing proper electrical relays

[twist]

After reading about using electrical relays for horns and lights and other stuff, I have to ask what amperage is best suited for the boxer system? I don't know where to begin picking the right part. Is there a rule of thumb for choosing electrical parts?

[Garnet]

The small Bosch (or equivilant) 30 amp 5 pin relay is avaialble at most auto parts stores fro 6 or 7 bucks.

http://www.bughaus.com/relay_0332019150.htm

[twist]

great! Perfect for duel horn installation. Thanks!

[twist]

since I know little about relays I have to ask: do I need separate relays for every device? For example, can I use the same relay for duel horn and heated grips? Seems like having a relay for each electrical use could get busy and messy.

[melville]

since I know little about relays I have to ask: do I need separate relays for every device? For example, can I use the same relay for duel horn and heated grips? Seems like having a relay for each electrical use could get busy and messy.

So when we hear your horn blaring we'll know that you are running your heated grips?

Plenty of room--here are, from left to right (front to back) Horn, Dimmer, and Starter:

[dwerbil]

since I know little about relays I have to ask: do I need separate relays for every device? For example, can I use the same relay for duel horn and heated grips? Seems like having a relay for each electrical use could get busy and messy.

So when we hear your horn blaring we'll know that you are running your heated grips?

Plenty of room--here are, from left to right (front to back) Horn, Dimmer, and Starter:

Mel, that's about as clean as clean can get. Sure makes it easy to troubleshoot/diagnose when things are
spiffy as that.

[twist]

I'd rather ask a dumb question and seem stupid than to do something stupid and be really dumb. thanks! Some one here said something like, think of relays as satellites. So I had to ask. I'm still not 100% clear on what relays do and why they're used.

[dwerbil]

I'd rather ask a dumb question and seem stupid than to do something stupid and be really dumb. thanks! Some one here said something like, think of relays as satellites. So I had to ask. I'm still not 100% clear on what relays do and why they're used.

Hey twist, for starters, er relays, here's a bit from Wiki on the subject....

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits, repeating the signal coming in from one circuit and re-transmitting it to another. Relays were used extensively in telephone exchanges and early computers to perform logical operations.

A type of relay that can handle the high power required to directly control an electric motor is called a contactor. Solid-state relays control power circuits with no moving parts, instead using a semiconductor device to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults; in modern electric power systems these functions are performed by digital instruments still called "protective relays".

[George Ryals]

Good resourse about relays

http://www.airheads.org/content/view/159/98/

[twist]

great, thanks! I'm a member and never noticed the relay faq and answers. (I must need new glasses)