Comments on: How to create your own laser home alarm system for under $20 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/ tech, science, news and social issues for geeks Tue, 14 Feb 2012 07:53:04 +0000 hourly 1 http://wordpress.org/?v= By: Sandeephttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-288532 Sandeep Sat, 22 Jan 2011 17:59:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-288532 Can't find the link to the video on this page. Have you moved the video? Could you please post it again. Thanks. Can't find the link to the video on this page. Have you moved the video? Could you please post it again. Thanks.

]]> By: cathberthttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-286689 cathbert Wed, 08 Dec 2010 10:30:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-286689 i would like to build a computerized alarm system that sends an sms where there is an intruder but i have no idea, help guys i would like to build a computerized alarm system that sends an sms where there is an intruder but i have no idea, help guys

]]> By: broothttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-256113 broot Sat, 03 Jul 2010 17:46:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-256113 1. where the base of transistor is wired to? To the positive of 9V battery and 5k variable resistor? Looks like the base of the transistor is wired to the positive +9V. The negative terminal of the battery is ground. the 5k variable is connected on one end to the +9V and the photocell on the other end. The middle lead (the wiper) is connected to the +9V as well. 2.There are three leads(legs) on variable resistor, which two are wired to the positive of 9v battery(which is the same point as wired to the base of transistor)? See above. 3. where the collector of transistor is wired to? To the negative of 12V DC Sire and the negative of 1000uF capacitor? Yes. The capacitor and siren are in parallel. 4. What type of photocell is the right kind? Can it be different kind or it has to be exact the same as it is shown in the video? If it is so, where to order one? Not sure what kind of photocell in the video. It looks pretty small. Ask for a mini photocell (1k light resistance/10k dark resistance). 5. How about the value of the variable resistor? I have 100K variable resistor that I used, is it a problem? Yes. Use a 5k. Remember to vary the resistor if the alarm goes off. You can try varying the 100k but it might be too sensitive. 1. where the base of transistor is wired to? To the positive of 9V battery and 5k variable resistor?

Looks like the base of the transistor is wired to the positive +9V. The negative terminal of the battery is ground. the 5k variable is connected on one end to the +9V and the photocell on the other end. The middle lead (the wiper) is connected to the +9V as well.

2.There are three leads(legs) on variable resistor, which two are wired to the positive of 9v battery(which is the same point as wired to the base of transistor)?

See above.

3. where the collector of transistor is wired to? To the negative of 12V DC Sire and the negative of 1000uF capacitor?

Yes. The capacitor and siren are in parallel.

4. What type of photocell is the right kind? Can it be different kind or it has to be exact the same as it is shown in the video? If it is so, where to order one?

Not sure what kind of photocell in the video. It looks pretty small. Ask for a mini photocell (1k light resistance/10k dark resistance).

5. How about the value of the variable resistor? I have 100K variable resistor that I used, is it a problem?

Yes. Use a 5k. Remember to vary the resistor if the alarm goes off. You can try varying the 100k but it might be too sensitive.

]]> By: broothttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276291 broot Sat, 03 Jul 2010 17:46:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276291 1. where the base of transistor is wired to? To the positive of 9V battery and 5k variable resistor?Looks like the base of the transistor is wired to the positive +9V. The negative terminal of the battery is ground. the 5k variable is connected on one end to the +9V and the photocell on the other end. The middle lead (the wiper) is connected to the +9V as well.2.There are three leads(legs) on variable resistor, which two are wired to the positive of 9v battery(which is the same point as wired to the base of transistor)?See above.3. where the collector of transistor is wired to? To the negative of 12V DC Sire and the negative of 1000uF capacitor?Yes. The capacitor and siren are in parallel.4. What type of photocell is the right kind? Can it be different kind or it has to be exact the same as it is shown in the video? If it is so, where to order one?Not sure what kind of photocell in the video. It looks pretty small. Ask for a mini photocell (1k light resistance/10k dark resistance).5. How about the value of the variable resistor? I have 100K variable resistor that I used, is it a problem?Yes. Use a 5k. Remember to vary the resistor if the alarm goes off. You can try varying the 100k but it might be too sensitive. 1. where the base of transistor is wired to? To the positive of 9V battery and 5k variable resistor?

Looks like the base of the transistor is wired to the positive +9V. The negative terminal of the battery is ground. the 5k variable is connected on one end to the +9V and the photocell on the other end. The middle lead (the wiper) is connected to the +9V as well.

2.There are three leads(legs) on variable resistor, which two are wired to the positive of 9v battery(which is the same point as wired to the base of transistor)?

See above.

3. where the collector of transistor is wired to? To the negative of 12V DC Sire and the negative of 1000uF capacitor?

Yes. The capacitor and siren are in parallel.

4. What type of photocell is the right kind? Can it be different kind or it has to be exact the same as it is shown in the video? If it is so, where to order one?

Not sure what kind of photocell in the video. It looks pretty small. Ask for a mini photocell (1k light resistance/10k dark resistance).

5. How about the value of the variable resistor? I have 100K variable resistor that I used, is it a problem?

Yes. Use a 5k. Remember to vary the resistor if the alarm goes off. You can try varying the 100k but it might be too sensitive.

]]> By: bhagyahttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-221433 bhagya Sat, 16 Jan 2010 15:32:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-221433 I'm going to make a laser base security system.but the problem is it must work all ina day.so i must find good laser source and photodiode or phototransistor or LDR for that.cost is not mention. i just need good quality parts. laser beam must go 40 feet without reducing its intensity and using sensor i want to get a pulse when laser beam cut.can you help me to find these laser source and sensor. I'm going to make a laser base security system.but the problem is it must work all ina day.so i must find good laser source and photodiode or phototransistor or LDR for that.cost is not mention. i just need good quality parts. laser beam must go 40 feet without reducing its intensity and using sensor i want to get a pulse when laser beam cut.can you help me to find these laser source and sensor.

]]> By: bhagyahttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276290 bhagya Sat, 16 Jan 2010 14:32:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276290 I'm going to make a laser base security system.but the problem is it must work all ina day.so i must find good laser source and photodiode or phototransistor or LDR for that.cost is not mention. i just need good quality parts. laser beam must go 40 feet without reducing its intensity and using sensor i want to get a pulse when laser beam cut.can you help me to find these laser source and sensor. I’m going to make a laser base security system.but the problem is it must work all ina day.so i must find good laser source and photodiode or phototransistor or LDR for that.cost is not mention. i just need good quality parts. laser beam must go 40 feet without reducing its intensity and using sensor i want to get a pulse when laser beam cut.can you help me to find these laser source and sensor.

]]> By: kykayhttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-205824 kykay Sun, 22 Nov 2009 11:04:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-205824 does it really work does it really work

]]> By: kykayhttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276289 kykay Sun, 22 Nov 2009 10:04:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276289 does it really work does it really work

]]> By: Delray Divahttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-178319 Delray Diva Fri, 07 Aug 2009 21:57:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-178319 ROFLMAO............um............I will never be able to make that. Can you just send the site to me of where I can buy that? lol ROFLMAO…………um…………I will never be able to make that. Can you just send the site to me of where I can buy that? lol

]]> By: Delray Divahttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276288 Delray Diva Fri, 07 Aug 2009 21:57:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276288 ROFLMAO............um............I will never be able to make that. Can you just send the site to me of where I can buy that? lol ROFLMAO…………um…………I will never be able to make that. Can you just send the site to me of where I can buy that? lol

]]> By: Dellahttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-176569 Della Sun, 02 Aug 2009 17:00:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-176569 it seem good solution for me. i’ll try it. thanks. it seem good solution for me. i’ll try it. thanks.

]]> By: Dellahttp://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276287 Della Sun, 02 Aug 2009 17:00:00 +0000 http://www.geeksaresexy.net/2008/03/03/how-to-create-your-own-laser-home-alarm-system-for-under-20/#comment-276287 it seem good solution for me. i’ll try it. thanks. it seem good solution for me. i’ll try it. thanks.

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