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  • Camera-alarm-trigger

    2016-02-18 16:16:3362

    Transistor Ql remains off until the magnetic switch connected to Jl closes. When that happens, the 9 Vis connected through Rl to Ql`S base. Ql turns on...

  • A theft alarm description BOP

    2016-02-18 15:52:2766

    Below is a description of theft alarm blowout preventer. With text to understand the schematic diagram will be more efficient to understand oh. The cir...

  • Personal Silent Alarm Systems Theory

    2016-02-18 15:42:5383

    This article introduces the principle of personal silent alarm systems. Please read the text, and then look carefully circuit. The Personal silent alar...

  • How to build An Enhanced Shed / Garage Alarm

    2016-02-18 15:39:0266

    Description This is an enhanced version of the simple Garage/Shed Alarm. The Entry and Exit delays have been increased to about 30-seconds - and I've a...

  • A refrigerator door alarm circuit diagram

    2016-02-18 15:32:4763

    This article is an introduction to the door alarmcircuit diagram. Do you have any idea on the circuit and opinions, welcome to contact us. At the same ...

  • alarm keypad - enhanced 4 digit

    2016-02-18 15:13:0263

    This article describes the enhanced four alarm keypad circuit. For your better understanding in the diagram, we recommend that you look at the text. Wo...

  • Astable oscillator Z80 processor clock circuit

    2016-02-18 14:24:08131

    The clock circuit is kinda cool. Its about as simple as you can get, with a 2.4576 Mhz crystal, a .01uf cap, two surface mount resistors, and two inver...

  • Automatically Turn Off The Alarm Delay

    2016-02-18 14:06:0386

    The alarm automatically turns off eight minutes delay circuit using NE555 timer and CD4020B. When the 12-volt DC circuit after being applied to the C2 ...

  • Fire Alarm Using Thermistor

    2016-02-18 14:04:5462

    Small and simple unit, Can be used for Home-Security purpose In this fire alarm circuit, a Thermistor works as the heat sensor. When temperature increa...

  • A refrigerator door alarm circuit

    2016-02-18 13:45:0363

    Next comes the refrigerator door alarm circuit theory. Generally, this circuit is enclosed in a small box in the refrigerator near the lamp (if availab...

  • One second Audible Clock Circuit Schematic

    2016-02-18 13:41:2565

    Accurate, finger-operated portable unit, 3 - 12V Battery supply This accurate one-pulse-per-second clock is made with a few common parts and driven fro...

  • Speed-limit Alert

    2016-02-18 12:37:5465

    Wireless portable unit Adaptable with most internal combustion engine vehicles Circuit diagram Parts: R1,R2,R19 1K 1/4W Resistors R3-R6,R13,R17 100K 1/...

  • Alarm System Using Radio Waves

    2016-02-18 12:14:0763

    Figure 1 The circuit was designed to provide an alarm system that would transmit signals across the medium wave or the radio wave. Medium Wave – oper...

  • How to build A Dozen Small Cmos Alarm Circuits

    2016-02-18 12:09:3663

    Description This is a selection of small self-contained alarm circuits. The main features of each alarm are described on the circuit diagram itself. Th...

  • How to build Fridge-Door Open Alarm Circuit Project

    2016-02-18 11:54:21100

    Description 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 a...

  • Alarm Indicator for High Temperature Reading

    2016-02-18 11:50:5262

    Figure 1 The circuit has been designed to provide an alarm with the use of a buzzer when sensing high temperature by using a thermistor. Thermistor –...

  • Practical electronic alarm circuit diagram

    2016-02-18 11:44:5065

    This article is practical electronic alarm circuit diagram. The principle is simple and very practical. Want more thoroughly grasp the principle, you s...

  • How to build Low Voltage Alarm

    2016-02-18 11:36:5366

    Description This low voltage circuit can be used to monitor batteries and other volatile sources of current for problems. The circuit sounds an alarm a...

  • Travel Touch Alarm Circuit

    2016-02-18 11:29:0488

    The article describes the tourism touch alarm circuit. The circuit is very simple, very helpful. Travel Touch Alarm can be used to provide an audible a...

  • Speed alarm

    2016-02-18 11:12:4365

    Pulses from the distributor points are passed through a current limiting resistor, rectified, and clipped at 4 volts. Via Q1 and the diode pump, a dc v...

  • Zero degree Celsius alarm

    2016-02-18 10:56:5668

    Description. This simple circuit will produce an alarm whenever the temperature falls below zero degree. A thermistor is used here to sense temperature...

  • Hydro alarm circuit diagram

    2016-02-18 10:45:1765

    Sensors This hydro alarm circuit detects the absence or reduced amount of water in a container. Circuit diagram is very simple and works as follows: N1...

  • How to build Fire Alarm Using Thermistor

    2016-02-18 10:33:4163

    Description In this fire alarm circuit, a Thermistor works as the heat sensor. When temperature increases, its resistance decreases, and vice versa. At...

  • Car alarm horn Beep eliminator principle of armed

    2016-02-18 10:07:5467

    This article describes a car alarm is armed corner Beep eliminator works. The principle is simple there, we recommend that combine text carefully read ...

  • Entry Alarm circuit

    2016-02-18 10:07:2974

    This is an Infrared based Brocken beam alarm to protect doors and entry passages. It gives a loud alarm when somebody crosses the Invisible Infrared ba...

  • Mains failure alarm circuit

    2016-02-18 10:03:2866

    ?Description. Here is a simple mains power failure alarm/detector circuit that produces an alarm whenever the mains supply fails. Lot of such circuits ...

  • Two-Zone Intruder Alarm

    2016-02-18 09:32:2868

    Description: This is a two-zone alarm - with automatic exit, entry and siren cut-off timers. It can be triggered by the usual types of normally-closed ...

  • Freezer meltdown magnet alarm circuit

    2016-02-18 09:30:2261

    The meltdown of freezers that destroyed about one-third of the worlds collection of autism brain samples could cause a major setback for autism and oth...

  • Touch Alarm System circuit diagram

    2016-02-18 08:47:32146

    Touch Alarm circuit is widely used for security, which is installed on the door. The advantages of this alarm is because the cost is cheap and difficul...

  • How to build Mains Remote-Alert

    2016-02-18 07:46:3363

    Warning! These units are connected to 220Vac mains, then some parts in the circuit boards are subjected to lethal potential!. Avoid touching the circui...

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