Fires can occur for several reasons, for example, forgot to turn off equipment that could cause such as irons, fire alarm circuit with a temperature sensor may be one option in an effort to secure our homes from fire hazards. Actually there is also a fire alarm circuits that use LDR, but I think it is less effective because it is basically a light
Click here to download the full size of the above Circuit.
sensor, that is the presence of smoke then the intensity of light falling into the LDR will decrease and the triggering circuit. But as as I said seems less effective. This fire alarm circuit use IC LM35 as temperature sensor. Wherein when the temperature in a room setting has been reached it will be triggering the circuit to sound an alarm. One that I like from the LM35 sensor is its sensitivity to temperature so as suitable for the temperature sensor, it is also easy to obtain. The LM35 output is fed to pin IC LM339 comparator IC is negative with a positive setting with a value input through the VR1 10K. VR is what will the temperature sensor sensitivity setting used. While the LM 339 is a comparator IC that has a 4 in it. Output on the comparator IC LM339 is fed to the transistor T1 BC547, how it works when output low / low, T1 in a state that serves as a cut-off switch is open, so it will work like a switch T2 is closed and the resulting pin 4 (reset) on the IC 555 to be low. And because the reset input 555 is low, the alarm does not work. and so if there is a trigger that caused the LM35 IC temperature which gives a chance has been reached. As for the installation of fire alarms can be placed around flammable materials or places where the potential occurrence of fire, and it seems like if we use multiple sensors to a circuit (diparalel) will work well for this LM IC impedance is low,
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.....
characters left: