Ignition for power switch... seen before, no details

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Stoopid Guy

Limp Gawd
Joined
Oct 1, 2004
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I'm wondering about buying an ignition switch (like in a car), or any type of lock with a key to twist and hooking it up as my power switch... I'm wondering if there's some special kind I need? Maybe one type would bounce back, another type I'd have to turn REALLY fast? I see abbreviations like SPDT and so, but can't find what these mean anywhere... Any help would be appreciated :)
 
Thanks..

Edit:
None of those item numbers for radioshack seem to work anymore, only one of them even exists, and there's no picture for it...
 
you might try in the case mod forum, instead. that's where stuff like this is usually covered.
 
Go to an autoparts store and look for ignition switches. Usually turning the switch to 'start' is momentary, so that would work for turning your computer on and off.
 
Stoopid Guy said:
I'm wondering about buying an ignition switch (like in a car), or any type of lock with a key to twist and hooking it up as my power switch... I'm wondering if there's some special kind I need? Maybe one type would bounce back, another type I'd have to turn REALLY fast? I see abbreviations like SPDT and so, but can't find what these mean anywhere... Any help would be appreciated :)
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I bought one recently for a project. You can get two types, one is a dual sided key and one a round key (like a vending machine or bike lock. Problem is, none of them are momentary. You might contact them to see if they have a monentary. I used my as a safety switch that you have to turn on before you can use the (momentary) power button

http://www.jameco.com

Catalog #'s

Round Key: 106649ER (.5" hole, .55 depth) $3.59

Flat, 2-sided key: 105831ER (.75" hole, 1.48" depth) $3.99
 
mcm has momentary key switches.


MCM Part No.: 26-500

Manufacturer: MCM

Manufacturer Part No.: 26-500
Description: KEY SWITCH (MOMENTARY)

Pack Details: 1
Minimum Order Quantity: 1
Order Multiple Quantity: 1
 
An ignition switch should work okay for this, if they're designed like I'm thinking they are. An ignition switch should be actually two switches in one.....a constant on switch, to keep things powered while your engine is running (works like a light switch, in other words), and a momentary on switch, that has the sole purpose of engaging and powering the motor in your starter, to turn the engine over (that you don't want to have power for more than a second or two).

As long as you run your wires to the negative of the switch, and the positive for the momentary, it should work like a power switch on a computer case. Good luck! :D
 
since no one else posted it.

the first two letters stand for how many poles
the second two letters stand for how many "throws" it has

explanation:

spst - single pole single throw
spdt - single pole double throw
dpst - double pole single throw
dpdt - double pole double throw

spst - has 2 contacts they are connect or switched to broken
spdt - has 3 contacts either 1 +2 or 2 + 3 are connected
dpst - I believe has 4 contacts basically 2 spst's (never seen one though) operate together
dpdt - has 6 contacts basically 2 spdt's that operate together

http://www.kpsec.freeuk.com/components/switch.htm
 
oh yeah momentary on are almost always spring loaded to only be on for the time you hold it. Like a team I was on built a robot with DPDT switches that were momentary on-off-on meaning center was off and you can push each switch up or down and it would pop back into place. We had 2 of these for 2 treads on each side of the robot. push both up and it would move forward. one up one back and it would spin circles. (like a RC tank)
 
An ignition switch has four poles, as shown below, switch position P1,P2,P3,P4
and terminals T1, T2, T3, T4. None are a ground

wire from mother board would go to T1, wire to motherboard T4

key in off position. P1, no connections T1, T2, T3, T4

Key in P2, T1 connects to T2, radio comes on :D

key in P3, T1 connects to T2 and T3, radio is on and ignition is powered

Key in P4, T1 connects to T3, T2 is momentarily disconnected and T4 is momentarily connected. starter cranks and engine starts, (hopefully)
P4 is spring loaded and when released goes back to P3, engine continues to run and radio comes back on. :D

To use an ignition switch would work and you can lock the computer on or off, but to change it you would have to turn the switch to P4, first time turns it on, the second turns it off.

The only problem I see is the switches are bulky and need an 1-1/2" deep area to be mounted. that can be overcome by a little planning and such.

Have fun
 
i have two key switches that i bought for both of my computers.....they just have two posts each and spring back after you turn the key......i think they're from the chicago lock company but i can't really remember....
 
I have a small locking barrel switch (like a vending machine) on a shuttle setup so it needs to be on to turn on/off the machine. No key for it yet as I pulled it out of a old at case and it didn't have a key. It is genric with no grooves on it so finding one won't be too hard.
 
Hit your local lawnmower repair shop. The ignition switches from riding mowers have 3 positions: off, on, and start (momentary). Less terminals to figure out, and they're a heck of a lot smaller and cheaper than car ignition switches. (I did a brief stint as a lawnmower repairman to take a break and get my head screwed back on after 26 years in computers).
 
LOL breathing the fumes wasn't the dangerous part...I stuck my arm up inside a machine out in the junkyard there and got stung by a scorpion! Had a 3 inch across black, yellow, and purple welt on my arm for two weeks!
 
Cool.... I've actually been looking around (not very hard, tho) for one of these to use as toddler-proofing on my computer. Stupid power/reset buttons have a nice bright blue led right next to them that is, apparently, fascinating.
 
uzor said:
Cool.... I've actually been looking around (not very hard, tho) for one of these to use as toddler-proofing on my computer. Stupid power/reset buttons have a nice bright blue led right next to them that is, apparently, fascinating.
Click to expand...

try duct tape
 
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