Colloquium: Innovations in Burglar Alarms - Questions/Discussions

Replies

• 

  cooltwins

  hey biggie,
  i have a problem .....😔
  i had made my circuit available as a hyper link in every page for the convenience of the readers..... but the hyper link does not work in the uploaded format....
  What am i to do?
  please help.....😒.
• 

  cooltwins

  somebody........😔
  please help.......
  i am clueless as to what to do now.......😔
• 

  Kaustubh Katdare

  Post it here. I'll upload it to the first post.
• 

  CIVILPRINCESS

  try tinypic.com to help you upload the circuit.
• 

  cooltwins

  
  
  this is the basic circuit.
  
  
  
  this is for the improved format of the burglar alarm. hope this will be enough. 😒 😒
• 

  sookie

  Hi cooltwins,
  
  Amazing work done.
  
  Pardon my ignorance, I could not see what were the drawbacks in earlier Burglar Alarm's circuit that are overcome in new Automatic Intruder Alarm clock? I couldn't find any information like what all innovations are being done in new Circuit Digram? Shall I assume that your Presentation was meant only for Electronics CEans? 😔
• 

  cooltwins

  sookie

  Hi cooltwins,
  
  Amazing work done.
  
  Pardon my ignorance, I could not see what were the drawbacks in earlier Burglar Alarm's circuit that are overcome in new Automatic Intruder Alarm clock? I couldn't find any information like what all innovations are being done in new Circuit Digram? Shall I assume that your Presentation was meant only for Electronics CEans? 😔

  sorry for not reaching out to you...
  and i am not sidelining my presentation to any particular engineering discipline students...
  it is for all crazy engineers here...😛
  
  any way here goes my explanation hoping to clear your doubts.😎
  
  1.) DEFECTS IN THE EARLIER CIRCUIT THAT WERE OVERCOME BY THE SECOND ONE:
  A) The most important thing changed was the introduction of the exit and entry delays which was not considered in the previous circuit. In case you are not familiar with these terms here goes the explanation:
  ENTRY DELAY:Once the alarm is set the circuit will be well set to sound the alarm, flash the outside lights or activate the telephone auto dialer in case some one breaks the circuit. but this is not required if the person who just entered is the owner himself. So this entry delay gives the owner time to walk up to the control box and disable the circuit and avoid false alarms.but once the entry delay has passed the sirens are sounded however.
  EXIT DELAY: It gives the owner time to exit the area after the alarm is set,without triggering the circuit.during this time the alarm cannot be activated.So it's safe to open the loop and exit the building. once the Exit Delay is finished if any one enters the area(even if it is the owner himself) it will trigger the circuit.
  
  B) The second most important improvement was the removal of voltage spikes.following is the detailed explanation of VOLTAGE SPIKES:
  
  What is it?:Spikes are fast, short duration electrical transients in voltage, current, or transferred energy in an electrical circuit.If the transient is in the form of voltage then it is a voltage spike,if the transient is current then it is current spike, in case of transferred energy it is called as energy spike.
  
  What causes it?:There are many reasons attributed to the formation of spikes. some of them are:lightning strikes,short circuits,electromagnetic pulses, malfunction by the power company,power outages.
  here is a picture of a voltage spike in a graph:
  
  
  What is the damage caused?:For sensitive electronics, excessive current can flow if this voltage spike exceeds a material's breakdown voltage, or if it causes avalanche breakdown. In semiconductor junctions, excessive electrical current may destroy or severely weaken that device. An avalanche diode,transient voltage suppression diode, transil, varistor, overvoltage crowbar, or a range of other overvoltage protective devices can divert (shunt) this transient current thereby minimizing voltage.
  
  What has been done to protect the devices in the second circuit?: Relay coils and some Sounders produce these large voltage spikes that will damage Cmos ICs. D1, D5 & D6 short circuit these spikes before they can do any damage.this feature is not seen in the 1st circuit in spite of use of relay coils and sounders which do cause voltage spikes.
  
  C)Over all, the reliability factor of the circuit has been increased in the second circuit. In the 1st one due to the doubts in the reliability of door switches, touch points were used as an added feature. but they are even more bad because these wires can pick up stray signals and there by activating the circuit.But this defect has been looked after by the capacitor C1 and C4 in the 2nd circuit.When using the touch point the tapping of the circuit must be well checked.If potentiometer VR3 tapping is held more towards ground, the alarm will get switched on even without touching.But the tapping point should not be raised too much as the touch action would then vanish. Even an Electric sparking in the vicinity of this circuit may cause false triggering of the circuit.But the 2nd one is not so loose and is reliable to some degree.
  
  
  2.)INNOVATIONS IN THE CIRCUIT:
  By the term "INNOVATIONS" i meant to convey about the improvements in this field of home security.The improvements in the 2nd circuit over the 1st one has been discussed and for further improvements do refer to the section : ANALYSIS OF THE NECESSITY OF VARIOUS COMPONENTS TO IMPROVE QUALITY in the ppt.
  By the use of title "INNOVATIONS IN BURGLAR ALARMS" i mean to point out not only the improvements covered by me but also the improvements that can be implemented on by the other engineers who have for long ignored this field.
  
  
  
  I hope i have answered to all your queries so far....😁
  Please do feel free to leave more queries if any:smile:
  I will do my best to answer them...:smile:
• 

  Kaustubh Katdare

  @ cooltwins, are your answers taken from Wikipedia?
• 

  cooltwins

  No sir,
  i have not copied anything from wikipidiea
  i have based these answers from my paper and presentation only and were manually typed by me from my understanding of the subject.
  i referred the net for the exact definition of a spike and its picture only...😕
  i don't know why this question was asked....😔
• 

  cooltwins

  i would also like to make a clarification that even my paper or my ppt has not ventured anywhere close to Wikipedia
  i do not mean to be rude i just want to clarify. 😀
• 

  Kaustubh Katdare

  No don't worry 😀, just teasing you . The topic is good.
  
  I was hoping to see some innovative thing about the way alarms function. I believe the innovations mentioned have been around over a decade. What are the latest improvements in the systems?
  
  Correct me if I'm wrong.
• 

  cooltwins

  The_Big_K

  No don't worry 😀, just teasing you . The topic is good.
  
  I was hoping to see some innovative thing about the way alarms function. I believe the innovations mentioned have been around over a decade. What are the latest improvements in the systems?
  
  Correct me if I'm wrong.

  looks like my topic has been getting more question than my content😁
  (just kidding....)
  any way lets get to the explanations....
  
  There are no changes in the basic system of the burglar alarms as such they are all based completely on the basic idea discussed in the slides #3 - #15. The improvements discussed reflect upon the increase in the reliability of the system and not on an entire change of the system. so there will not be any visible difference over system over time. But there is a significant increase in the reliability of these systems, and that is something one has to agree…
  
  
  I have only pointed out the errors in the 1st circuit and the possible remedies. Then the second circuit comes into focus and looks like even that is not reliable as shown by the defects pointed out. But I have suggested some possible remedies too which did sound good up to my knowledge.
  
  As I had said earlier the innovations don’t stop with what I have mentioned there is lot more to be carried ahead by us so as to attempt and bring about significant changes in home security.
  
  As said in my abstract.......
  

  But the rule of science is that a perfect circuit never stays so for long, because the very next day someone can point out to a mistake that had been neglected so far. But as the mistakes are being pointed out and rectifications are being made the ultimate result is: a far well developed circuit which is more reliable. But all that one has to understand is HOME SECURITY is a field full of scope for engineers.

  hope i have attended to all your questions.
  please feel free to leave any more queries if any
  will be happy to answer them...😁
• 

  CIVILPRINCESS

  nice presentation cooltwins...😁
  
  any way could you please explain the working of BASIC MAGNETIC SENSOR in the slide#7.it was meant to be self explanatory. but it would be better if you explained.pardon my ignorance...😕
• 

  cooltwins

  CIVILPRINCESS

  nice presentation cooltwins...😁 any way could you please explain the working of BASIC MAGNETIC SENSOR in the slide#7.it was meant to be self explanatory. but it would be better if you explained.pardon my ignorance...😕

  
  thanks..... civil princess
  here is the required explanation:
  
  A magnetic sensor in a closed circuit consists of a few simple components. For the most basic design, you need:
  (1)a battery powering a circuit
  (2)a spring-driven metal switch built into a door frame
  (3)a magnet embedded in the door, lined up with the switch
  (4)a separately-powered buzzer with a relay-driven switch.
  
  Process:
  
  Now what happens is that:
  
  Step 1: the spring driven metal switch is responsible for the electrical contact in the circuit. The moment it is displaced the circuit becomes open.
  
  Step 2: the magnetic sensor is responsible to hold the metal switch in contact by exerting a magnetic force over the metal. It is important that this magnet can exert enough force to overcome the force caused by the spring to try and pull the metal away.
  
  Step 3: now when the door is opened the magnet is displaced and this will make the magnet lose its power over the metal so the spring gains advantage and pulls the metal away so the circuit is now open.
  
  Step 4: the open circuit will cause the separately-powered buzzer with a relay-driven switch to start the alarm.
  
  This is the basic working.
  
  With just a battery and buzzer, these designs make for fairly flawed security systems. After all, the burglar only needs to close the door again to turn the buzzer off. That's why most modern burglar alarms incorporate another piece into the circuit -- the control box.
  
  
  hope i have cleared your doubt.
  please do feel free to leave more queries if any.
• 

  arjun_rp

  nice presentation cooltwins
  
  could you please explain me why a cmos is used in this circuit? what are the advantages of using cmos?
• 

  cooltwins

  CMOS:
  
  The Automatic Intruder Alarm uses a Cmos 4011. The 4011 has four two-input NAND gates. NAND gates only produce a low o/p if both i/p are high.
  
  WHAT IS A CMOS?:
  Complementary metal–oxide–semiconductor (CMOS) is a technology for making integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits. CMOS technology is also used for a wide variety of analog circuits such as image sensors, data converters, and highly integrated transceivers for many types of communication
  
  
  
  
  REASON FOR THEIR USAGE:
  
  1)One of the main advantages that CMOS technology, which makes it the most commonly-used technology for digital circuits today is the fact that it enables chips that are small in size to have features like high operating speeds and efficient usage of energy.
  2) they have very low static power supply drain most of the time. Only when the transistors are switching between the two states (on and off) do you find a significant level of power drain.
  3) devices using CMOS technology also have a high degree of noise immunity.
  
  ADVANTAGES OVER TTL LOGIC?:
  1)CMOS devices can run on about 3 to 18 VDC
  Whereas, TTL voltage is fixed at 5VDC.
  
  
  2)CMOS devices are voltage driven, and use less power than TTL. A major concern if the Device is battery driven as in our case.
  
  3)Bread boarding experimental circuitry is easier with CMOS.
  TTL is susceptible to all kinds of noise problems as it is current
  driven.
  
  hope i have answered all your queries
  please do feel free to leave more queries if any😁
• 

  cooltwins

  @sookie, @biggie, @civilprincess, @arjun_rp
  
  are you all satisfied with my answers?😕
  or do you require more explanation?:neutral:
  i will be happy to answer them😁
• 

  vishnu priya

  Good presentation ..
• 

  Ashraf HZ

  Oh interesting, I used the 2nd circuit (Automatic Intruder Alarm) for one of my lab projects. Good old times 😀 Where did you get it from? I forgot the website which I used before.. maybe its the same one?
  
  Your presentation was titled as "innovations" in burglar alarms. What other ways can burglar alarms be made more effective in the future? Is there a better way to verify if the intruder is friend or foe? Maybe that saves effort for the real user try to disarm the alarm manually.
• 

  cooltwins

  vishnu priya

  Good presentation ..

  thanks vishnu😁
• 

  cooltwins

  ash

  Oh interesting, I used the 2nd circuit (Automatic Intruder Alarm) for one of my lab projects. Good old times 😀 Where did you get it from? I forgot the website which I used before.. maybe its the same one

  I am sorry ash I did this project in the very start of my 2nd year and 4-5 months have passed and I am not able to recollect the source of the circuit diagram……..😔
• 

  cooltwins

  ash

  Your presentation was titled as "innovations" in burglar alarms. What other ways can burglar alarms be made more effective in the future?

  Again looks like my topic has been getting more question than my content 😁 (Just kidding....) any way lets get to the explanations....
  
  As such There are no changes in the basic system of the burglar alarms as such they are all based completely on the basic idea discussed in the slides #3 - #15. The improvements discussed reflect upon the increase in the reliability of the system and not on an entire change of the system. As I had said earlier the innovations don’t stop with what I have mentioned there is lot more to be carried ahead by us so as to attempt and bring about significant changes in home security. So the only way to make burglar alarms more effective is the improvement in the reliability in the circuit. As said in my abstract.......
  
  

  But the rule of science is that a perfect circuit never stays so for long, because the very next day someone can point out to a mistake that had been neglected so far. But as the mistakes are being pointed out and rectifications are being made the ultimate result is: a far well developed circuit which is more reliable. But all that one has to understand is HOME SECURITY is a field full of scope for engineers.

  The other possibilities of improvement lie in the usage of better facilities like face recognition or voice recognition like the blue eye technology that is wide used nowadays.
• 

  cooltwins

  ash

  Is there a better way to verify if the intruder is friend or foe? Maybe that saves effort for the real user try to disarm the alarm manually.

  Yeah the manual attempt by the user to stop the triggering of the circuit is a bit time consuming and if the person forgets the code and the delay is long the circuit may be triggered and false alarms can cause a lot of embarrassment. 😀
  
  But the use of voice recognition at the entrance itself the user can identify himself and the person's act of intrusion will not trigger the circuit.so it can save the time of the user and in the case of forgotten passwords…. Face recognition can also be used along with voice recognition at the control box areas….. these have been used actively in blue eye technology systems.
  
  In places like museums, banks where safety is of prime importance we can use finger print recognition systems or retinal scan systems, but this would be totally out of place in a house. 😀
  
  Hope i have attended to all your questions.
  Please feel free to leave any more queries if any will be happy to answer them...😁
• 

  Katherine22

  There are many alarm systems on the market today, and the choice is enormous. Determine which system is best suited to your needs is difficult, it is useful to understand the differences between simple main types of alarm systems yet. There are three main types of alarm system and it is wired, wireless and independent. wired alarm systems are often referred to as the more traditional security system.
  
  #-Link-Snipped-#