Electronics Pull Pin Switches (like a grenade), anyone make them?

I've been working various angles to conceal and protect my carpc installation. Lot's of break-ins around here and I feel like I could do better.

Then I had an idea. What about a really loud ear-piercing alarm powered only when the car was off (I have an alarm system too btw).

I'd bury it deep within the dash, with a pull-pin type switch keeping the contacts open. The pin would be attached via a steel cable to the back of the center console (were the LCD is embedded) with only an inch or so of slack. I'd have a second slighty longer steel cable securing the center console as well.

So someone smashes the window and if they manage to get the center console free, it pulls the pin and emits an ear-piercing shriek. Then they'd have to contend with the other cable, all while trying not to go deaf. Hard to cover both ears with one hand

A sonic grenade if you will. I think it's pretty good idea. The only thing I'm not sure on is if they actually make switches like that, and what are they called? I know I could jury-rig it, but I'd prefer to buy one and they aren't too expensive.

Anyone know?

Thanks,
-Lee

 

I'm pretty sure I've seen them on personal alarms, but never in a catalogue as just the switch bit.

 

Like a pull switch that is activated by a line being pulled the style used in busses for stop request. Page 852 or search for cable pull switches http://www.mcmaster.com/ I would recommend a timer of about 10 mintes or 30 minutes as even you would be annoyed.

I couldn't find switches that would close the circuit when the wire is pulled but Im sure you could wire a circuit that would arm when a circuit is opened.

 

Thanks. "Cable-Pull Emergency Stop Switches", eh?

They look perfect but pricey, think I'll take the low road. I was thinking a pic or 555 to drive it. I've got tons of both, but the PIC stuff usually ends up better

Analog is not my forte.

I saw something like that while googling on Make (or hackaday?), given the price, probably will go that route or rig something up.

 

I'm sure you could easily make a pull to close switch from a wooden clothes peg, some foil and a plastic strip. Foil round the two ends of the peg and and the plastic between the two... Pull the plastic out and the two ends join. Should cost less than 20p for that I reckon!

 

Take a look at industrial emergency stop switches. Most are a "Press to stop, pull to start" design, but there are also some with a "in=off, out=on, pull=start) design which might workbetter for you. THey are also incredibly durable and I think reasonably cheap.

I'd really like to figure out how to integrate an E-stop button in my next computer, but I can't figure out what it should stop

 

With a bit of quick and dirty modding you could get it to perform the pause function, it'd be very satisfying to hit every time you go for a drink

 

Another thought is a jack plug & socket. The socket switch action is usually break with the plug in IIRC, so makes if you pull the plug. Many sizes, including power ones.

 

Shotgunefx, they sell those at the local Radio Shacks (just don't ask the employees about them...they won't have a clue as to what you are talking about). Fairly cheap too, maybe $2 or so.

 

Nice idea... I once had another idea for securing my car.
Using a some storng strobe lights to blind anyone who's trying to have a look inside the car, after he opened it without the proper key
I got the idea when I saw a smoke machine for car security. The smoke prevented any thief to actually see what he was looking for...
As that system costs a fortune I thought about something similar and cheaper.

 

when they steal a car radio you take a pair of snips , and once the radio is so far out you snip all wires at the back . with this in mind , could you make the pull switch wire so tight that when the radio was pulled forward it would activate before they saw it and snipped it , just a thought

 

try adapting a micro switch.
idea 1 ms is wedges between pc and something else- pc removed switch triggers alarm.
idea 2 scaffolding arond ms to provide pull pin type trigger.

 

micro switch is a miles better idea , and couldnt you wire it in somehow to lock the cetral locking . it wont stopem gettin out but it will slow em down and you might catch the little f***er

 

i made a trip switch for a buzzbomb (trip switch buzzer comes on, latched to stop it heing reset) for the ATC. it was easy to mak:

i glued the microswitch to the box, with the leaver arm pointed to one wall.
the pin goes between the wall and microswitch arm, keeping a connection.
remove pin, connection lost, buzzer goes off.

simple!

 

Thanks for all the feedback.

Certainly doable, but a little too jury-rigged. I want something that is going to reliable and rugged.

Now that's a thought!, I briefly considered it earlier as it's pretty much out of the box what I'm asking for, but couldn't think of how to make it contact with nothing in there.

Now that you mention that, thinking about trying to repair the audio jack in my laptop, it did make a set of contacts with no plug as well. Though mating a cable to it securely enough might be a little difficult.

I've got a bunch lying around and even more ripped off of old printers and other devices. I almost never throw anything electrical away, I strip it for parts first.

Yeah, RS doesn't know too much (not the one near me anyway). Though occasionally an employee will suprise you. Not too often though.

That's why it's going to be so taut, though often the break-ins are drug addicts who usually don't have any tools.

Behind the center console, it's a vaccuum. A lot of empty space. No good place for a setup like that. The PC is secured (more so anyway) in the trunk.

Something like that has been on the todo list for quite some time, it's all done by the ecus and not the actually switches. I still need to get a scope so I can try and decode the signal.

I wouldn't want anything that could blind me while driving if there was a malfunction.

As far as smoke, one problem I can think of is that if you heat the solution too hot, it becomes formaldehyde, so I'd be a little wary of that.

I did have another idea for a smoke machine. For a smoke screen. No, I would never use it, but just to do it for the sake of doing it. (I watched too many bond movies growing up)

I was thinking it would be pretty easy, run some aluminum tubing around the exhaust to a aresol tip and just pump it through. No warm-up time

The big trick I think would just be figuring how how many turns you'd need to get the solution at the right temperature by the time it reaches the nozzle.

It would rob you of some heat in the exhaust which could in theory be problematic, might get some condensate which would rot it out quicker, maybe some backpressure. One of these days I'll find out

 

Can't you make a pull-pin switch out of a 1/4-inch phono connector? Have that wired to a NC relay that prevents the alarm circuit from being powered when the plug is inserted.

Or something setup with a Normally Closed snap action switch triggered by a peg.

 

The phono plug is starting to look good. Providing I can find a plug that has a set of terminals that make on removal, I was thinking of having it powered by a NC relay (that would be opened with the ignition, so I can easily bypass it when hacking stuff in there).

 

gotta be careful with that. theres a good chance it could cause a short because most aren't designed for power...

 

Hmmm, well if you want something design for power just use a Barrel-type DC power connector and plug.

Won't short when connected/disconnected either.

 

Contingency planning...

A survivors story....

I've been installin' car audio since the introduction of the pioneer
8-track supertuner. Professionally for several years. I had a system
jacked in WVA right out in the city police parking lot!

So I went to work. Not in the vein you are, but in pure revenge mode.

I mounted all systems since then with straight razors. You reach in
you loose fingers period. I installed several system this way. Had a
nice pool of blood on the floor of my mustang (along with a shattered
sidelight) one evening after a date at the movies.

2 weeks later the paperwork arrived. 3 months or so later the litigation
was over and I *yes* I had to PAY a lot AND I MEAN A LOT of
money to settle that mess.

All I can offer is to NOT make the system loud enough to cause
bodily damage (at least not in US) or peirce eardrums.

You might be another one "protecting" their investment and
paying for your cars damage as well as the theif's doctor bills!

FWIW