Search for protection in Topics

paper protection?

How can i make: 1) photo-copy evident protection (when photo-copied will show void) 2) how can i make special markings such as are on official documents and store gift cards by myself to protect my documents ?

Question by kaerez    |  last reply

Need a protection circuit?

Hi i am making my own speaker system. i am using this amp the issue im facing is that a few days ago i power this amp with a smps 12v 1amp supply and it was working fine till something went wrong with the psu and there was a spark in the psu, the major problem which occurred  was that this caused a surge which travelled through the amp to my audio source which in this case was my computer. i ended up frying my sound card . can anyone help me make some kind of protection circuit which allows audio signals to pass through but does not let current from the psu pass through.

Question by cfrek    |  last reply

protecting from EMF?

So i am working on some high power geophysical transmitters which are being damaged by back emf. can anyone help me with what would be the best way to protect the instrument from this. we are mainly blowing the switching IGBT's. the transmitter is supplied DC from a 30kw powersupply, feeding a set of IGBT's which are switched at a selected frequency usually 0.5 to 2hz at 50% duty cycle into a loop of wire ranging in resistance but usually around 1 ohm. we run this at up to 150A at 150V and our loads can be very inductive, usually 300mx300m 25sqmm copper wire. im thinking diodes or caps for a bit of protection. im open to any ideas

Question by benmerlingeo    |  last reply

Patent Free Protection?

Hello: I have an idea that I wish to keep free for all to use. Does publishing on Instructables count as Prior Art to the US Patent Office? Does the Patent Office check Instructables in patent searches? I check Patent Free on all my Instructable ideas, so is this enough? Thanks, Carl.

Question by carl5blum    |  last reply

DIY Protective Helmet? Answered

So I'm looking at starting a helmet project with the good ole' pepakura halo helmets, but taking it a step further. Essentially what I am wondering is how one would go about adding some protective foam or padding that can absorb impact (I'm talking motorcycle grade here). The design I'm looking at calls for some custom work, otherwise I'd just gut an existing helmet off the shelf. Does anyone have any ideas on accomplishing this? I'm thinking the helmet shell will be carbon fiber for added durability so I'm hoping to get some feedback on what everyone thinks would be the best protective layer for the inside. Also, please no "For your own safety just buy a helmet and don't worry about the looks" This is a novelty just for fun, but I'd like to know I could use it if I wanted to. Let me know what you think!

Question by Antilliteracy    |  last reply

Protection against EMP ...

Hi !Data :Let's say that I want to protect some important electronics devices against EMP.Let's say that they need to work 24/7 and that they are, thus, connected to an external source of power (electrical socket before EMP, and solar panel after EMP).Let's say that they need to emit and receive RF signals.Questions :1) As there are electrical connections with the exterior, a Faraday cage would be pointless, wouldn't it ?2) Would a solar panel survive to an EMP ?3) Is this possible to use the Faraday cage as an antenna for RF communication ? (I guess it's a stupid question as connecting the cage to the device would make the cage part of the device ...)4) Are thin and transparent gold foils enough to act as a Faraday cage ?_Edit : Interesting readings found thanks to the links Nachomahma provided : : an article about EMP protection.The first part is about EMP from nuclear bombs. The last part gives some clue about HMP.

Topic by chooseausername    |  last reply

How to make 18650 circuit protection?

Help me to build circuit protection for single cell without IC. I need schematic too. Thank you.

Topic by myhobbies  

Over voltage protection circuit

Hi everyone! So i was making one of those water level indicator circuit: I found the construction to be fairly easy for a newbie for me. I modified the circuit according to my needs, and have successfully constructed it. There is a small issue though. The place i live is susceptible to over voltages often and our fuse system is presently out, so my family has discouraged me from implementing the circuit at home in my main water tank. They want me to add a over voltage protection circuit so that they can feel safe. So anyone has any idea on how to construct an overload protection circuit(The circuit should be simple and understandable for a newbie like me)? My supply mains are 230v AC. It can either be before or after the transformer stage.

Topic by charmquark    |  last reply

Is there a better way to protect faucets in a hard freeze than letting them drip all night?

I'm in north Fl. and our hard freeze is about 5 to 6 hours under freezing. The problem with the dripping faucets is that it uses up the softened water.

Question by Scapegoat    |  last reply

How do you keep your email private? Answered

I have Gmail I noticed that ad banners appear on the subject that is contained in the email. Is there any way to stiop this from happening?

Question by lakeoconee    |  last reply

Can I produce an image in Microsoft Paint and assign that image to a "hotkey"?

I would like to use that image as a character in the password for my computer. This is so a dictionary program wouldn't be able to break through a password for my computer. Is this possible?

Question by LeShane    |  last reply

i was wondering, how do you make cheap protective body armor ?

It dosnt have to stop a bullet or something just gives you protection from knives and punches thnx

Question by tevon    |  last reply

UsbSafe² . Usb Safety Device! OpenSource, EEvblog

I have designed a new usb anti Juice Jacking device which will protect your private data from harmful attacs. It will also protect your Hardware by over voltage protection and current monitor. Check out the video below when Dave from EEVblog finds it in the mailbag. Also a short demovideo is attached!! Functions has been added and the features now are: 1 Anti Juice Jacking function. 2 OVP. Over voltage protection. 3 Current fuse functionality. 500mA/900mA/1500mA/2100mA/2400mA This project will go live ASAP at: At launch design files will be public! Navigate to prelaunch page and subscribe for release info!

Topic by Karoly Simon  

Solar Cells Coating? Answered

Hi Guys! A few weeks ago I found an auction on ebay, bid, and won myself some big old pack of solar cells. Now these panels are wafer thin, no coating or covering. Additionally, I need to put the wire collecting ribbons on myself. The only problem with these is that they are incredibly fragile. What can I coat them with to protect them? Is there any spray or acrylic or resin that you use to protect them? Thanks

Question by transistorguy    |  last reply

how could a glove be made into a faraday cage?

would wrapping foil/wire mesh around it work? and would it be effective(and by effective i mean the wearer doesnt get zapped)?

Question by Aercimete    |  last reply

Lithium Ion protection circuitry?

I was wondering.... The protection circuit for li ion cells in phones; is it a sort of regulator for the battery when charging? Or does it just stop the cell from being drained too far? I was wondering if I could use the circuitry from the prismatic li ions found in mobile phones for a 18650 battery....will the difference in capacity be a problem?

Question by .Unknown.    |  last reply

EMP and Solar Flare Protection

I uploaded the videos on Youtube: Make sure to look at the description below the video for more information on forums and links. Tell me what you think. Mac

Topic by macb6497    |  last reply

Best protection for computer... LIGHTNING

I've heard of computers fried in electrical storms, even with a surge protector. 1) Is there a better way to protect it, short of unplugging? a friend mentioned connecting it thru a bus, and letting the bus act as a fuse. I'm not sure what he was really getting at. 2) What are the odds? 3) experiences + anecdotes?

Topic by Toga_Dan    |  last reply

protection tips for lifepo4 battery?

Its a 24 v 30 AH battery to be used in a trike.Apart from the protection circuits  what(materials) could be used to fill the battery surface to avoid more damage to the vehicle in case of a disaster? Any usual practices?

Question by Nr-Think different    |  last reply

Protect steel without paint.

I decided to try my hand at making jewelry with a cheap piece of steel. Partly, because of price and partly due to not being able to find a large enough piece of stainless. It turned out great. However I know it will rust if I don't protect it somehow. I'd prefer not to paint it l, because of the work to buff it to a high shine. Any ideas on how to protect it from rusting when in contact with skin?

Question by BernardR23  

Develop - Protect your invention

Hi All,Has anyone found a good article re: developing and then protecting your invention?There are all these TV ads for companies to help you file a patent application which seem dubious.Have you found other forums besides here to ask questions as you go along and develop your invention?Are there any engineering forums where you can discuss with design engineers how to build a prototype or model or create blueprints for it?Thank you!

Topic by eager to learn    |  last reply

Game Interface Protection Software

 Have you ever had someone break into a password-protected file/folder by finding out the code? Well, if someone made a Game Interface Protection Software, they don't need a code! The software would have these following traits: 1. The user could choose through a variety of games (like chess or poker) to use as the protection. 2. The user could set the game difficulty level. 3. The user could also have a password after the game, just in case someone else got through the game. 4. The user could also have the game set so the person would only be able to win by a certain way. Ex: (On chess) D1 to C4... If someone here could make this software, I'm sure they would have a nice business.

Topic by Blackhawk2    |  last reply

How to protect OpAmp output?

Hi, I have an OpAmp which controlls the Gate of a MOSFET. When the MOSFET dies, sometimes the voltage it's running on (50V) somehow gets to stand over the OpAmp's output which destroys it. What's the best way to protect the OpAmp from the high voltages that get to stand over the output? Will a zener do the trick? Trigger transformer won't be easy to use here because It's a PWM controller so I need nice block waves. Diode on the output? but won't this be bad for delivering good current to the Gate? ... Any ideas?

Question by DELETED_Electorials    |  last reply

Protective Cover for Solar Cells? Answered

I have a commercial solar panel that has burned out cells.  I figure this is a great candidate for overhauling.  I notice that the cells are protected with what appears to be clear silicon with a clear plastic covering, Tedlar or Kevlar?  Anyone know where to get large quantity of silicon for large pour of covering?  It would appear to me that after the cells are assembled the silicon would be poured and then the plastic cover placed on top and the some sort of rolling pin or squeegy to smooth out, this would be better than plexiglas laid over the cells,  hail could hit it and not break anything.

Question by Foxtrot70    |  last reply

dust protection for computer and router?

Im the designer for a plastic/wood furniture shop. I'm having problems keeping dust from computers, even with equipment not in the workshop.  (office on the side) what would be the best design to keep airflow for computers and hardware but minimize the dust. Thansk.

Question by ebaltierrez    |  last reply

18650 protection board limitations

Hi ThereI've been lucky enough to stumble across a large quantity of brand new 2600 - 3300mAh 18650 cells and I'm wanting to find some DYI projects to put them to good use. 200W flash light, electric Go Kart or a basic power wall comes to mind. However first things first Ill be needing to build them into a packs and connect them to protection modules but Ive got a few questions:Protection modules come in so many flavors. 2S - 3S - 4S - 5S - 5S5P and bigger.. Do you choose the module based on how many cells you have in total and then just use a DC-DC converter to get the required voltage? Or do you try to get as close as possible to the voltage needed in series first and then find a module that suits? What is the most versatile configuration?Can I connect 5S5P pack to a 5S module? Can I keep increasing in parallel with no consequences? Like for example can I connect a 5S15P pack to a 5S model and expect the module to be able to balance and charge the pack back up? I understand there are Amp draw limits to watch out for too. The module I was looking at is below. this module requires a charge voltage of 21 volts at no more than 5Amps. Where would I be able to find a charger like that? A laptop power brick maybe?Any guidance would be great as I'm keen to learn as much as possible!Thanks in advanced!

Question by Plangy  

Protecting You From the Boogyman

Both my girlfriend and my sister are afraid of the dark. I've heard so many stories and them waking up in the middle of the night, hearts racing, and then checking under the bed before they run to the bathroom. Afterwards, they run back and literally jump into the bed and hide under the covers. While this is infinitely amusing for me, I'm sure it's not as fun for them. What could actually be really cool is if the iCreate could sleep near the bed and the wake up when motion is detected, turn on a light and then follow the person to the bathroom shining a beacon of safety/boogyman death ray. ;) It's actually not as innocuous as it sounds. To pull this off some of the classic problems in robotics would have to be solved including object tracking (probably using infrared), collision avoidance and coordinated movement all using the iCreate. If you think about it, the possible extensions are many... perhaps on command the iCreate could play a chosen melody to soothe you back to sleep; perhaps each person using the iCreate could have a different colored light to shine the way; and if you could do that, perhaps you could also mod it into party mode where it would shine a bunch of lights in a pattern while it played songs. Groovy. I'm really excited by the possibilities and ideas floating around as a result of this contest, so thank you iRobot for the opportunity, we're slowly getting there!

Topic by althalinelife  

Protecting You From the Boogyman

Both my girlfriend and my sister are afraid of the dark. I've heard so many stories and them waking up in the middle of the night, hearts racing, and then checking under the bed before they run to the bathroom. Afterwards, they run back and literally jump into the bed and hide under the covers. While this is infinitely amusing for me, I'm sure it's not as fun for them. What could actually be really cool is if the iCreate could sleep near the bed and the wake up when motion is detected, turn on a light and then follow the person to the bathroom shining a beacon of safety/boogyman death ray. ;) It's actually not as innocuous as it sounds. To pull this off some of the classic problems in robotics would have to be solved including object tracking (probably using infrared), collision avoidance and coordinated movement all using the iCreate. If you think about it, the possible extensions are many... perhaps on command the iCreate could play a chosen melody to soothe you back to sleep; perhaps each person using the iCreate could have a different colored light to shine the way; and if you could do that, perhaps you could also mod it into party mode where it would shine a bunch of lights in a pattern while it played songs. Groovy. I'm really excited by the possibilities and ideas floating around as a result of this contest, so thank you iRobot for the opportunity, we're slowly getting there!

Topic by althalinelife  

Homes Protected from Raging Forest Fires

Every year we hear about countless homes being destroyed by forest fires. Unfortunately, the public isn’t aware that our current level of technology can readily address this problem. I have been examining a concept that has intrigued me over the past decade and which I call a “fire shield”. This shield functions by completely enveloping a private home and protecting it against encroaching forest fires. We’re talking about protection against a blazing fire storm generating high speed winds and flames in excess of 100 MPH. The shield would be a flexible structure that easily inflates like a balloon (needing perhaps three people for a day to erect) and forms a protective hemispherical, shell-like dome over the home (Fig-1). The structure would be impervious to penetration by high speed flames and their intense radiant heat, thereby keeping the enveloped home safe, cooled and protected. Each home would require a pre-fitted, customized buildup of a number of pre-built modular, balloon-like segments. They are manufactured and then assembled over the house only once, to get a customized tailored fit, then taken down and stored, and thereafter are ready to be deployed within a day’s advance notice of an encroaching forest fire. The Fire-Shield would be a modular, portable, inflated dome like those used for indoor tennis, which is prepared and custom-fitted to be later erected within a day. While typical inflated domes have their entire inner volume pressurized, our Fire-Shield will only require pressurizing a small volume contained between its double-walled structure that forms the dome as shown in Fig-1. The surface of its outer material uses NASA's radiatively reflective, aluminized Mylar to ward off the intense radiant heat of a fire storm. In addition this surface gets protected against the 100 – 150 MPH fire-winds, which are ready to impinge upon it, by injecting a high speed film of air (just like gas-turbine blades) produced by portable blowers. The actual heat-shield contains multiple, redundant pockets of cells directing the flow of air to both film-cool its surface and protect the shield against direct flame contact. Each major modular segment would contain its own portable, gasoline powered wind generator to supply the airflow. Depending upon home-size, several of these modules would be easily connected using Velcro plus redundant snaps and safety-stays. The shield gets attached over chimney tops and to pre-installed, grounded cement-posts, plus strategic hooks about the outside of the house. Special, inflated pillows are also strategically placed (between the shield and the house exterior) to facilitate the formation of a hemispherical shield that envelopes and protects our home against a high speed fire-storm. The Fire-Shield Design Concept The concept for a fire shield went through a gestation period of several decades as my career in thermo/fluids evolved. It started with the design of jet engine turbine cooling to thermal control of satellites, and finally to designing radiant heat barriers for cryogenics. These activities enabled receiving a score of patents as well. These activities inspired the concept for a rapidly deployable Fire-Shield to protect homes against a raging forest fire. The idea requires integrating several technologies ranging from inflatable commercial air domes to jet engine cooling to radiatively cooled spacecraft. Also included are flexible material coatings developed by NASA that radiatively reflects high temperature heat, making the deployable Fire-Shield a viable concept. Two key design principles are employed to protect both the heat shield and the home it envelopes. The first is shown in Fig-2 and uses a high speed film of air (faster than the anticipated fire-storm flame speeds of 100 – 150 MPH) that is locally directed to blow over the shield’s surface, cooling it and protecting it just like the metal turbine blades of jet-engines. The temperature of speeding flames impinging upon a jet engine’s metallic turbine blades is hot enough to easily melt them, yet the blades are protected by using this film cooling technology. The same technology will protect the heat-shield from meltdown when high speed flames of 100+ MPH attempt to impinge upon its surface. The second principle protects the shield against the intense radiant heat coming from a blazing forest fire where temperatures can exceed 2000 F. While this radiant heat does not physically touch the shield, as would a fire-storm’s flames, its presence is “felt” and is as deadly as the hot flames that would normally scrub over the shield without our film-cooling. We use a radiatively reflective, thermal coating barrier that repels this radiant heatload and protects the shield from melting. Such coatings were originally developed by NASA to protect satellites and spacecraft. The coating gets applied to the shield’s outer domed surface and will reflect better than 97% of all intensive radiant heatloads that are incident upon the dome’s surface. (Patent Pending; Original Concept Documented in 2006)  

Topic by RT-101  

Why should you build a rooftop lightning protection system with either all copper or aluminum components? Answered

I bought a book from Home Depot to learn about household wiring:;=books&qid;=1279657048&sr;=1-1 On pg. 238, about lightning protection systems, it says, "...these instructions are for copper only-do not use copper with aluminum." Why shouldn't we use copper components with aluminum? It's essentially just a couple of lightning rods and a cable leading to a ground rod. I can scan the page if you'd like to read it. They made it sound fairly important. 

Question by Vorenus    |  last reply

Inrush current limiting resistor size?

I am building an application where LED strip lights will be powered off a 12V DC battery and switched on and off using a magnetic reed switch. I've been finding that the reed switch often fails to turn off when the magnet is removed. Searching on the net suggests this is because the contacts are getting fused by a large inrush current and the suggested fix is to wire a resistor in series to prevent this - so far so good but I cannot find anywhere guidance on the rating of the resistor I should use - at least guidance I can understand - as far as I can tell a resistor as low as 1 ohm may be required but not sure if I have got this correct - anyone know? Thanks

Question by SeaF1    |  last reply

how to run starforce protected game?

i installed CRC 2005 game today but it's not worked, because starforce error pop up and it's a empty massage . i tried starforce update tool and removal tool but both didn't  work and i tried some crack file,another error shows java script wrong. Anyone know how to run a game without this starforce protection ? i think good programmers know how to do this ... pls... i want to play this game 

Question by ishan udyoga    |  last reply

IP protection for open source hardware?

If my solar condenser ends up working I'm wanting to make it open source. I realise that this means effectively giving up all ownership of it, and that's fine, but the last thing I want is for someone else to go and patent it and stop anyone else from using it. What protections are available for this kind of thing? Patents obviously, but is there anything a little less intensive? I'll be looking into copyleft and creative commons and all that, but if someone can point in the right general direction first it'll save me some time.

Topic by SolarFlower_org    |  last reply

Such a thing as a variable voltage/current overcharge protection?

I've had a couple of bad transformers in battery chargers in the last couple of months and I am thinking of building my own variable voltage/current battery charger with an ST Microelectronics L200. Figure #23 But I would like to have overcharge protection so I don't have to monitor the batteries charging once I set the volts and current for that battery. Something that would just shut off or switch to a trickle charge when the battery reaches the voltages I want or set. Also, another question - I am intending to use a salvaged transformer from an old chamberlain garage door opener for this project and need to know the best method for lowering the voltage from it to something the L200 can handle. It's a 1:3 and takes my 125v main to roughly 42v and the L200 is rated at a maximum of 40v input. I was figuring on just using a resistor, but I don't know how to calculate what I need since the current and voltage will be changing the load on a per battery basis. Also I think the transformer might be a little small for this project, it only measures about 2"x2", while most of the chargers transformers were twice the size or more. So I'm wondering if it might not be able to handle the constant power or heat requirements for charging. *Added a pick of the transformer. And since I've asked this many questions, I might as well add another. I was looking through the "how to get free electronic parts" pages and I didn't see any on solar cells. Does anyone know if any company does samples for cells the way they do for electronic parts? I am capable of following simple to moderate schematics and can solder well. But when it comes to making new circuits and such, I tend to just hobble together something I've seen or used before that works. When it comes to programming and calculating circuit load and all that I become bogged down pretty fast. If I can see it and experiment with it till I get it right, I am better off and maybe learn something. So the simpler the better.

Question by Dochide    |  last reply

what is the spesification of photocell in this scematic????

In the arrangement of laser beam home protection system i need to knw the spesification of photcell used inthis arangemt and also the laser intensity i.e hw many refelctions it can endure and how much area it can cover??

Question by 9260074    |  last reply

Invention without a patent, what happens if someone steals it??

Ok, I've got a really cool invention. My oldest boy came up with the idea like 6 years ago. I can't afford to patent it. If I used the idea in an instructable, would the date on the ible help prove that the idea was ours? (Or would it just prove how stupid I am by letting the "cat out of the bag"?) I don't mind other people making their own, that's what Ibles are about. I just don't want someone to run patent it, and then commercialize it unfairly.

Topic by skunkbait    |  last reply

how make a write protected pendrive?

Dear all          I need to make a write protected pendrive to protect my pendrive from viruses. after the protection it should be readable in dos mode without any password, but no body can write or edit files on the pendrive. Thanks Chameera

Question by chamksn    |  last reply

How To Password Protect Your Files (??)

If any of you know a good program i can use to password protect my files please tell me! Or if you can tell me how to do it please tell me! Rick,

Topic by rickick    |  last reply

Combo- Locktight / Lube/ Corrosion protection

Stuff like lugnuts... sometimes exposed to damp for years. then, the one time in yrs u havta loosen it, maybe it's rusted.  AND youre in the middle of nowhere without many tools. So. Is it bad to put oil on those spots? Dont want em vibrating loose. But that would protect against corrosion and permanent seizing. Best practice?

Topic by Toga_Dan    |  last reply

Are the pictures in our instructables protected by copyright?

I see one of my photos all over the internet without a link to the original material.

Question by cpacker1    |  last reply

What is the best virus protection software?

I've been using Spyware Doctor for about five years and it seems to be working for me. I turn off the Intelliguard feature because it slows down my computer a lot! I'd like to know what everyone else uses.

Question by Packers Widow    |  last reply

Is this the right kind of Diode to protect a Servo with? Answered

I would like to protect my Servos from accidentally reversing the voltage on them and frying them. The power source is 6v (4x AAA battery) and the Servos each draw a maximum of 6v, I am unsure about the amps due to a lack of datasheet, but have been told that they draw a maximum of around 1A per hour. I have 4x and was planning to use , one for each servo. Does this make sense/will work? Thanks in advance for your help.

Question by Hammock Boy    |  last reply

Protecting my new power supply

I've got a 12vdc 500ma power supply that I'm using to trigger a few solid state relays. I'm also using the same power supply to provide input current to a little micro PLC (Automation Direct DL05). Both the relays and the PLC have a wide range of acceptable input voltages and their current requirements are about 15ma per channel at 12 volts. The count is 6 relays and 8 PLC inputs, if all are on thats about 210ma. I once killed a similar power supply by allowing the leads to touch and short-out. I would like to protect this power supply from the same fate by protecting it from short circuit. I thought about attaching a reisistor to the end of one lead and covering all but the outlet of the resistor with heat shrink tubing... problem is, it would have to be a big, bulky power resistor to handle the wattage. Is there a simple component available that will limit the current upon short circuit that I can place in series with my loads to protect the power supply? As I said, it doesn't have to be precise and it doesn't matter if it jerks the voltage around a little.

Topic by fluoronator    |  last reply

How to protect computers from grandfathers? Answered

This is somewhat of a funny question, but I am in a need of a serious solution. My grandfather always manages to mess his computer up with virus/ crapware/ malware /. He is running Windows 7 and I am trying to lock his computer to prevent install of new programs/ crapware. Something similar to what they use on college computers. Any one know of the software? that I can use?

Question by Eax5    |  last reply

Getting into a password protected Samsung Computer?

My brother died in February. I have his relatively new Samsung laptop but I can't get into it because I don't know his password. The first screen that comes up is his name, his email address, and then it asks for a password. I tried the directions for Windows XP system but nothing happened when I held the F8 key so maybe his operating system is not Windows XP but Vista or something else. Can you help?

Question by 3R    |  last reply

Back EMF protection for ignition coil

Hi, i made an ignition coil driver circuit (check image) witch is nothing special cause they are everywhere on the internet but what's really bothering me is the back EMF that would fry the 555IC so if i put a rectifying diode (IN4007) at the VCC pin and the reset pin (like in the circuit image) would it solve the problem? Btw this is my first post so sry for any unclear information, thx.

Question by SND SND    |  last reply

Protect my house on mischief night?

Last year my house was egged in a drive by "shooting". in past years there were attempts at TPing my tree but its like 200' so it was a fail. Anyways i need suggestions on how to defend my house. so far i have Airsoft sniper in the tree Water hose Super Soaker Flame thrower Chasing them on a bike with a 100Db alarm on it MORE airsoft guns Paintball Bazooka "homemade" Camera flash for blinding them Firecrackers (possibly if i can find them in time) panic button for car alarm POSSIBLY putting a trail of gasoline on the road so in case of a drive by someone in the bush can light it and scare the crap out of driver and prevent them from leaving Playing random music VERY loud and getting like 10 people to give a GIANT group hug SMOKE BOMBS Night vision (kipkay design) pitch forks and torches Please any other ideas would be helpful

Question by tomtortoise    |  last reply

how to construct a low voltage protection system using annunciator?

Hi in our college for our first year mini project , we were given a problem statement and based on it we have to find a solution , but i am not able to ,so here is the problem statement "low voltage protection system using annunciator generate 5volt power supply from 230volt ac and activate beeper when power supply is below 180volt.choose components with appropriate materials.list the important property based on which the material is chosen for the components .draw the waveforms of current and voltage at specific branches and node.find the laplace transformations ." so if any one  does come across some ideas please help i have my first review coming by so reply ASAP guys

Question by archanapurvi    |  last reply