30 Threads found on edaboard.com: Alarm Open Circuit
could any one help me out how to run this is rainy alarm circuit design, when there is no rain my circuit suppose to be open circuited. but my problem is when i open circuit the probe and simulate there is still voltage across the variable resistance, and the variable r
Analog Circuit Design :: 15.03.2011 18:17 :: charick :: Replies: 2 :: Views: 480
I would like to desing a house alarm System.
Any circuits available?
thanks a lot
Professional Hardware and Electronics Design :: 29.06.2002 04:43 :: savvasn :: Replies: 6 :: Views: 2060
i need to design a circuit simply give alarm when fluorescent lamp stop working , can this done by current sensing or what ? :arrow: :? :?:
thanks for anybody wants to help
Fire in the Wire :sm2:
Professional Hardware and Electronics Design :: 19.08.2004 01:21 :: fireplus :: Replies: 10 :: Views: 1585
what is your request, i fact it is not easy to realize the VSWR alarm accurately!
so you should provide more information for your request!
RF, Microwave, Antennas and Optics :: 06.08.2005 02:20 :: springf2000 :: Replies: 2 :: Views: 637
i want to design fire alarm system using AT89c52,
but i dont know how smoke detector works, or what is its behavior when it detect smoke, to enable me to know that there r fire at any place.
what its out voltage in normal state and in fire state??
Hobby Circuits and Small Projects Problems :: 18.10.2005 05:40 :: eng_ahmed22 :: Replies: 2 :: Views: 1165
I have a circuit which contais pic16f887. It's an alarm system with a lcd.
When I try to simulate it on proteus, the simulation doesn't run properly. There's nothing displayed on the lcd and I get an error regarding the pic, specifically between ra0 an ra5 outputs, wich are connected to the lcd. Someone help me please and I would be very thankful.
PCB Routing Schematic Layout software and Simulation :: 14.02.2008 11:48 :: alcindo :: Replies: 6 :: Views: 5074
I have the need for an alarm when house power fails. I purchased a sump alarm which trips on high water. The sump alarm probe is normally (low water) open. When water rises it closes and the alarm goes off. I want to substitute a normally open ciruit when house power is applied which (...)
Analog Circuit Design :: 03.10.2009 19:44 :: 1geo :: Replies: 3 :: Views: 1209
anyone can help me how connect this two circuit....the operation is the output from TRI from Ultrasonicradar circuit will activated the alarm circuit which is already connected..How i can make the output from TRI will activated the siren and strobe light simultaneously.....Which part i should
Hobby Circuits and Small Projects Problems :: 12.10.2009 03:28 :: 89Panadol :: Replies: 1 :: Views: 1197
I explain my problem. Please give me some ideas.
I have a signal from a sensor. The signal has pulses each 20ms. Each pulse has a duration of about 100us.
I want to design a very fast circuit that compare the maximum value of the signal with a digitally controlled threshold. When only one pulse is higher than the threshold, the circu
Analog Circuit Design :: 13.10.2009 14:30 :: pozzugno :: Replies: 0 :: Views: 1044
This is my first post here and I must say it looks to be a very informative site. I found this site while searching for an answer to the problem that I am having with the alarm system that I built found HERE .
The problem that I am having is this. Everything works great on zones one and two
Microcontrollers :: 02.12.2009 15:11 :: Jman 31 :: Replies: 0 :: Views: 549
The small square IC is the real time clock and display controller. It's custom for Sony so no data sheet is available. If you have an oscilloscope and can probe for the pin that changes state only when the "buzz" alarm is active, you may have a chance.
Hobby Circuits and Small Projects Problems :: 24.01.2011 20:11 :: KJ6EAD :: Replies: 1 :: Views: 2295
I want to build a laser alarm circuit but some of the posts in the internet are not so clear for me..
Can anyone post here some schematics of that alarm that:
* Keeps beeping until the tact switch is pushed and turns off.
* Can adjust the beep for a certain time..
* And also have a pot that adjusts the sensitivity of the LDR.. (...)
Hobby Circuits and Small Projects Problems :: 29.09.2011 23:29 :: joemnice :: Replies: 1 :: Views: 990
I Need Help With This Problem >>> Laser alarm circuit
I Built This circuit
& Connected The Out But From The Relay With Police Siren circuit
But I Got a Problem >>>> The Alert St
Hobby Circuits and Small Projects Problems :: 29.10.2012 07:53 :: dragon700000 :: Replies: 2 :: Views: 844
I have a 12v power supply and a flow switch which is closed when water is flowing through it and open when water isnt. I want to make a simple piezo alarm + LED light that tells me (comes on) when water STOPS flowing. How do I do this? That is, how do I take a normally closed switch and make it normally open? Simple is best for me and the (...)
Hobby Circuits and Small Projects Problems :: 09.01.2013 03:12 :: peters.carl :: Replies: 4 :: Views: 964
I want a simple alarm circuit that turn on when receive an interrupt from another micro controller.....
Microcontrollers :: 10.01.2013 22:58 :: armghan11 :: Replies: 3 :: Views: 253
Perhaps the original design didn't use one of the conventional 40KHz piezo devices. The guess at the frequency was mine, not the original posters although I've never seen one that works on anything but 40KHz. Possibly it used a small open disc as used in lower frequency alarm sounders.
I *think* the intention of the diode is to stop the transist
Analog Circuit Design :: 21.01.2013 11:14 :: betwixt :: Replies: 10 :: Views: 255
Yes, remove R13 and D1 of the second circuit and connect the collector of Q1 to VCC of the wailing alarm. And that should do it.
Hobby Circuits and Small Projects Problems :: 16.07.2013 10:21 :: marius810327 :: Replies: 4 :: Views: 299
It beeps if the fridge door is left open for too
long or hasn't closed properly, to stop food
from spoiling. There are lots of other uses as
well. A refrigerator or freezer door that is left
open or ajar may cause the food contents to
spoil. In some cases, the internal temperature
of the fridge or freezer will be maintained if
Hobby Circuits and Small Projects Problems :: 02.08.2013 02:08 :: nhawan429 :: Replies: 0 :: Views: 13
I've done something look alike (wireless house alarm). I mordified wireless door bell (very cheap on the market). open the transmitter and receiver, get the chip no and find the datasheet. With proper switching (for the code), you can control several receivers with one transmitter. You can easily adapt it for your puspose.
Hobby Circuits and Small Projects Problems :: 05.09.2004 22:39 :: Shu :: Replies: 3 :: Views: 673
i need help to begin design an alarm system for cars ...any paper a chart site to begin i hope use a pi16fxx or 68hc11a1
Professional Hardware and Electronics Design :: 30.11.2004 10:06 :: buhafsaek :: Replies: 3 :: Views: 941
This circuit is applied in remote control, car door open, close and alarm.
But, I cannot find this IC.
RF, Microwave, Antennas and Optics :: 03.02.2005 18:26 :: david753 :: Replies: 5 :: Views: 786
I have a problem with a RF POWER LDMOS:
When i try to test a RF Power LDMOS with a multimeter after about 3 seconds
Drain-Source junction gives me short circuit alarm and Trasistor is dead!(at first
multimeter shows like a diode but it falls down and goes to about zero)
Is there any way to check Static Characteristics
RF, Microwave, Antennas and Optics :: 20.05.2006 15:13 :: memarian :: Replies: 5 :: Views: 778
you can you an IR transmitter/receiver pair........
when the door opens the circuit breaks and the alarm sounds
Embedded Systems and Real-Time OS :: 24.08.2006 23:26 :: alvarorahul :: Replies: 7 :: Views: 1688
I think the following can help you:
AVR 2006 DESIGN CONTEST
GRAND PRIZE: WITNESSCAM
The WITNESSCAM is a self-recording surveillance camera that?s perfect for the home or office. The innovative, ATmega32-based system features a VGA CMOS color camera, a passive-infrared (PIR) movement sensor, and a 1-GB SD card. The aesthetically pleasing
Hobby Circuits and Small Projects Problems :: 01.01.2007 15:56 :: svicent :: Replies: 4 :: Views: 2227
May be a little delayed answer, but if U still needs help, pls. let me know.
Regarding PIR sensors, the usual way is to connect the relay contacts that are NC, in series, then, when any sensors triggers, it´s relay will open the contact and of course, the complete circuit ( loop ) will open indicating an alarm condition. (...)
Hobby Circuits and Small Projects Problems :: 24.01.2008 08:38 :: omore :: Replies: 5 :: Views: 1506
I think the WITNESSCAM can help you in your school work
The WITNESSCAM is a self-recording surveillance camera that?s perfect for the home or office. The innovative, ATmega32-based system features a VGA CMOS color camera, a passive-infrared (PIR) movement sensor, and a 1-GB SD card. The aesthetically pleasing prototype looks like an ordinary ala
Microcontrollers :: 15.12.2008 15:51 :: svicent :: Replies: 6 :: Views: 4911
Why don't you try using a window comparator circuit. Fire alarm circuits work as a "short" for alarm and an "open" is circuit trouble. Using a LM339 Quad comparator would allow you to build 2 complete comparator circuits. If the micro you are using has (...)
Microcontrollers :: 08.05.2010 21:34 :: BobK :: Replies: 1 :: Views: 1056
I am working with 6mbp15rh060 IPM form Fuji, and i am implement 3 phase inverter and it gives good output waveforms on Vdc=12v. but i noted that when DC current increase more than 1 amper the output alarm is ON. I think it is for overcurrent protection, but in datasheet this device can withstand up to 15A, why? and if it for overcurret how
Power Electronics :: 20.11.2011 08:00 :: Ahmed4444 :: Replies: 5 :: Views: 586
Use the following circuit with the changes values
R1 = 2.2MΩ
R2 = 18kΩ
R3 = R5 = 1kΩ
R4 = 1MΩ
C2 = 10nF
T1 = BC557
Electronic Elementary Questions :: 20.04.2012 20:49 :: papunblg :: Replies: 8 :: Views: 656
im a newbie.. so sorry for non technical terms I am going to use..
I had made a circuit that gets opened for a very short time and then gets closed again as it was before. (this happens in less than half second)
but I want to make an alarm that will run when the circuit gets opened and will continue to (...)
Electronic Elementary Questions :: 20.12.2012 12:28 :: kartik nighania :: Replies: 1 :: Views: 163