With these, you can make your very own security system that gives intruders a sporting chance! It`s the laser-version of saying But before I kill you, Mister Bond This laser tripwire system will trigger an audio alarm (made from a 110dB piezo personal alarm from the 1$ store) when something breaks the laser beam, which is provided by a si
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mple laser pointer. What makes this Hollywood-style is that when the beam is broken, the unit Beeps three times. If the beam is STILL broken after the 3rd beep, the alarm sounds. (If the intruder backs off and unbreaks the beam before the 3 beeps are over, the alarm does not sound). These are best used when placed somewhere that is physically confining, like around tight or low spaces so an intruder cannot simply run through all the tripwires. Any area that constricts movement is ideal. For example, the tripwires which require the intruder to quickly break contact to avoid and alarm can work well in conjunction with the Hollywood-style motion sensors, which require the intruder to STOP moving to avoid an alarm! This project uses some electronics and a PIC (12F629). If you own or have access to a PIC programmer (and know how to use it!) you will be able to make and modify this project as long as you possess basic electronic skills. If things and terms like regulated voltage, HEX files, and pullup resistors don`t mean anything to you then you will have problems if you try to make this project. The laser tripwire alarm assumes the light sensor is being lit by a laser when it is powered up. It will attempt to calibrate itself at powerup. Power up the alarm, and when the LED is blinking quickly, break the beam. When the LED lights solid, unbreak the beam. The LED will turn off and begin a slow heartbeat blink. The sensor...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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