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[on:]

Hi everyone

I need a relay and I need it today :-( ... now I am in a fairly small city, which does not have an obvious store which would have something like this in stock (Kingston, Ontario.)

Does anyone have an Idea where I could find something like that? I am going to check out auto-parts-sellers in the area, but does anyone have anything else which comes to mind? My biggest problem is, that in most stores, the people I ask have no idea what I am talking about, so they are hardly any help....

What cheep devices use relays? Where can I scavenge one?

Any help would be apreceated - I have an art project to excibit in on Monday, and I need that part :-/

Thanks

p.

[Reply #1 on:]

Radio shack?

[Reply #2 on:]

IF you have any small transistors, if you had some source of 12 volts DC (like an old PC power supply? THEN you could use a relay with a 12 volt coil. THEN you could get one at any Auto Parts store, IF you can find someone there to pick a small relay, not for some specific-specific thing like a 1989 Subaru Impreza Windshield Wiper Relay.

Although that would probably work 

Radio Shack IF you can find one. IF they know what a relay is.

[Reply #3 on:]

What do you need to switch?  How much does it draw and at what voltage?  Do you have any other components at your disposal? Are you triggering it with arduino or some thing else?

If you get a relay the coil needs to be drivable by the arduino and you will need a diode to protect the arduino.

Other things to look at, in no real order:
optoisolator and triac
electrical shop (dawn to dusk sensor, home automation)
X10 stuff
Pro audio or lighting shop that does installs
for automotive (all 12 V)  look at heavy duty flasher with coil, head light relay.
Reed switch and wire?

[Reply #4 on:]

i hate the source (which is the canadian equivilant of radioshack it seems) even more than radioshack, plus they never hav any of the things you actually need... and no relays there.

i finally was able to get a relay from some autoparts store, but it comes with absolutely *no* documentation. like zero. ziltch. it doesnt even (haha. I'm not even 100% sure its a relay, but the drawing on it suggests it.) Anyway, I am just assuming it requires 12 volts. I have some transistors and some opamps lets see... should be able to do something with this...

I also got myself one of those "from dusk to dawn" switches, whitch I will try if the above solution fails.

... oh what I would give to live in a city with a large electronic components store which has competent employees who dont give me a blank stare when I start talking about microcontrollers ...

Do they even exist?

... in kingston there is a great hobby store, with a guy who actually knows his electronics (at least a lot more than I do) but they have a shitty inventory for anything except RC cars. ... in germany they have conrad where they have *everything* in stock, but where they cant deal with do it yourself people. I have been refused service there, after they asked me what potentiometer I want and I answered "I dont care, just something nice and big"...

oh well...

I better get busy.

cheers and thanks for the ideas

p.

[Reply #5 on:]

oh. and thanks for that tip with the diode. wouldnt have thought of that

[Reply #6 on:]

i finally was able to get a relay from some autoparts store, but it comes with absolutely *no* documentation. like zero. ziltch. it doesnt even (haha. I'm not even 100% sure its a relay, but the drawing on it suggests it.) Anyway, I am just assuming it requires 12 volts.

The "standard" automotive relay is known as a "Bosch" relay (it's a brand name, but has become something like "Kleenex"); most are SPDT or SPST in function, and have a standard pinout. There are sockets available for them, too. However, most of the time you can't go into an auto parts store and just ask for a "Bosch" relay; they'll look at you funny, then ask for a make, model and year of your car.

Here's a couple of sites detailing them (in looking this up, I found out that they are now made by "Tyco" - but they'll likely be referred to as "Bosch" relays for the rest of time):

http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/relay.htm
http://www.bcae1.com/relays.htm

They aren't too expensive new, but if you have "pick-ur-part" auto junkyards, they may be found there even cheaper. They are fairly easy to control with small transistors and the like.

Also, another source for smaller relays are old modems (internal or external); they will usually have one for taking the phone line off-hook.

[Reply #7 on:]

The source seems to have relays.

http://www.thesource.ca/estore/Search.aspx?keywords=relay

[Reply #8 on:]

they'll look at you funny, then ask for a make, model and year of your car.

haha. yep. exactly beautiful how car dealers are predictible wherever you go :-)

*
@zoomkat. my local source didnt have any when I was there. oh well