generating "safe" electric shocks - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: January 24, 2013, 07:55:06 am
content: I'm looking to make something that will generate a shock when something metal that it is wired to is touched. (some little shit knicked my windscreen wiper).Maybe generate a a high voltage and charge a capacitor ? I assume the safest way to make it safe (controlled amount of power) is to switch the cap over from being charged to to being connected to the metal object so that continuous power is not applied

author: ftransform
author_rank: Frequent Contributor
timestamp: January 24, 2013, 08:01:07 am
content: They will end up torching your car or breaking a window with a stone from a distance.Instead of building a castle perhaps you should consider moving out of the hood. Seriously given the hoodlums behavior your car will become a huge target if it pisses them off. Every time they are drunk and bored they will go on the hunt for it for some laughs at your expense.Perhaps if you can program your car to run the lot of them over.

author: GK
author_rank: Super Contributor
timestamp: January 24, 2013, 08:27:05 am
content: Yeah, seriously bad idea, unless you have a comprehensive insurance policy on the vehicle.That said, here are experimental projects no. 117 and 118 from a once popular "150 IC-IN-1 Project Kit" that was sold by Dick Smith. Not something you'd see in this day and age. I wonder how many family pets were tortured because of thisEDIT - wow, that picture got more hits in 20 minutes that what my log amp schematic did in 2 weeks.

author: grumpydoc
author_rank: Super Contributor
timestamp: January 24, 2013, 09:06:58 am
content: Stupendously bad idea - you'll be guilty of assult at the least (get it wrong and it could be a lot worse) and you don't know that you'll catch the culprit or some bystander.So, however satisfying it would be - don't do it.

author: Psi
author_rank: Super Contributor
timestamp: January 24, 2013, 09:43:38 am
content: I've not really looked into car alarms lately but there used to be a type that would turn the entire car body into a capacitive proximity sensor.If anyone touched anything metal, or even came within 1cm of it, the alarm would go off.As entertaining as it is to give thieves electric shocks it's never a good idea.You either kill them or piss them off and neither is going to end well for you or your car.Any shock strong enough to hurt runs the risk of killing someone with a weak heart.Some loctite on the new windscreen wiper bolt should prevent randoms from being able to undo it without serious tools.

author: Simon
author_rank: Unknown
timestamp: January 24, 2013, 09:50:10 am
content: As I have previously found the wiper lifted up I suspect kids messing about. Yes I could use an very loud alarm as a first step.On my income I can't afford to move, my sister has already had to move because of neighbor trouble and frankly she could have equally as much trouble with the new neighbors. I'd be in the same boat.

author: Psi
author_rank: Super Contributor
timestamp: January 24, 2013, 09:52:48 am
content: You could also buy a car-cover.From the kids point of view it would take too much effort to remove when there's other peoples cars they can mess with instead.

author: Unknown
author_rank: Unknown
timestamp: January 24, 2013, 09:56:04 am
content: Mosquito alarm?http://en.wikipedia.org/wiki/The_Mosquito

author: Psi
author_rank: Super Contributor
timestamp: January 24, 2013, 10:00:16 am
content: Something as simple as a motion activated light may work too.Make it as bright as possible and they will be unable to see anything outside of the illuminated area because their eyes will adjust for that bright light level.People don't like that because, if all the can see is black, then they can't keep a watch out for other people.

author: Simon
author_rank: Unknown
timestamp: January 24, 2013, 10:34:15 am
content: Quote from: Psi on January 24, 2013, 10:00:16 amI had thought of that too. The problem with a car cover is i get fed up of putting it on and it means putting a lot of moisture either into my house or car when I store it.

author: amyk
author_rank: Super Contributor
timestamp: January 24, 2013, 11:46:12 am
content: Quote from: Psi on January 24, 2013, 10:00:16 amHow about xenon flash tubes... several of them triggered in quick succession can temporarily blind.

author: GK
author_rank: Super Contributor
timestamp: January 24, 2013, 12:47:29 pm
content: That is something I once considered, but a camera is only effective as a deterrent if you advertise its presence. Something to consider; suppose some little bastards were up to no good on your street, and then walk past your property with its "Smile, you're on camera" sign out the front. Depending on what they were up to, they might then be desperate to get their hands on the recorded evidence, making your property a target.A powerful xenon strobe light going off throughout the night every time a cat runs past would probably start to piss the neighbors off pretty soon if it illuminated any windows.

author: GK
author_rank: Super Contributor
timestamp: January 24, 2013, 01:12:54 pm
content: I was only talking in general in the case that the presence of a camera is advertised to have a deterrent effect.

author: Simon
author_rank: Unknown
timestamp: January 24, 2013, 01:13:33 pm
content: Quote from: AcHmed99 on January 24, 2013, 01:03:53 pmI'm not sleeping in my car at night O0

author: Simon
author_rank: Unknown
timestamp: January 24, 2013, 02:18:23 pm
content: i MAY GO FOR A LIGHT FIRST IF i HAVE ANY MORE PROBLEMS AND AFTER THAT LOOK AT AN ALARM SYSTEM THAT MAKES A LOW SOUND IF THE CAR IS TOUCHED AND IF THEY CONTINUE AFTER A CERTAIN TIME GOES OFF FULL BLAST.BUT HOW CAN i DETECT SOMEONE TOUCHING THE CAR ? SOMEONE SUGGESTED MAKING IT A CAPCITIVE SENSOR BUT SURELY THE HUMAN BODY WON'T DO MUCH TO ADD CAPACITANCE, OR IS IT THE DISCHARGE EFFECT ? OR SPEED OF VARIATION.

author: nctnico
author_rank: Super Contributor
timestamp: January 24, 2013, 03:12:09 pm
content: One of my former co-workers made a car alarm with a remote buzzer using a 433MHz transmitter/receiver and some DTMF chips. When the car alarm goes off, it will send a DTMF tone over 433MHz which triggers his receiver. You don't need a microcontroller to make this work!

author: SeanB
author_rank: Super Contributor
timestamp: January 24, 2013, 03:20:02 pm
content: Simon is in the UK, camera central, with more cameras than people. Does not seem to help. The CCTV is good, they give great evidence, though you will need 2 systems, one visible and one to watch who vandalises it that is well hidden. The recorder will have to be well hidden as well, or at least the one that works, so that if the scum break in and nick it they get a broken one only and are on candid camera as well.The car alarm systems with touch sensing use an IR transmitter and are mounted on the rear view mirror, so that as you approach they trigger on the larger return pulse after the gate time that ignores the windows. That should be silent, with a remote warning that it is triggered instead of a loud siren. Siren is for regular alarm.

author: Simon
author_rank: Unknown
timestamp: January 24, 2013, 03:29:04 pm
content: Quote from: nctnico on January 24, 2013, 03:12:09 pmi'D JUST REPLACE THE 433 MHZ TRANCIVER WITH A VERY LOUD ALLARM, THAT WILL TELL ME THERE IS A PROBLEM AND SCARTE THE LIVING SHIT OUT OF THEM. MY MAIN CHALLENGE IS DETECTING SOMEONE TOUCHING THE CAR. THE MICROCONTROLLER WOULD BE TO MANAGE THE TIME BETWEEN A LOW VOLUME ALERT ALARM AND A VERY LOUR "FUCK OFF"/ALERT THE WHOLE STREET ALARM.

author: nctnico
author_rank: Super Contributor
timestamp: January 24, 2013, 11:27:38 pm
content: Quote from: Simon on January 24, 2013, 03:29:04 pmThe thing with alarms is that nobody is looking what is going on. Its just annoying if it goes off in the night. IMHO it should be enough if the car makes a loud beep when someone touches it and you get a message. Just don't turn it into a circus act. Sometimes you just find your car in worse shape than when you parked it. I once had to get 6 new tires from the tire shop because some assholes punctured the tires of about 10 cars in the street. I really feel your frustrationDetecting someone touching the car is an interesting problem though. Maybe you could do something with a microphone inside the car. A touch should be a relatively sharp single pulse.

author: ftransform
author_rank: Frequent Contributor
timestamp: January 25, 2013, 12:38:04 am
content: Is simon upset or is he typing from a APPLE II?

author: Simon
author_rank: Unknown
timestamp: January 25, 2013, 06:51:52 am
content: Quote from: ftransform on January 25, 2013, 12:38:04 amif your referring to the caps it's because I was at work and working on drawings so had caps lock on as everything I put on a drawing has to be in capitals and I end up forgetting it's on.