The alarm detector circuit is different from Ultrasonic Alarm (1). In Ultrasonic Alarm (1), an alarm output is presented when there is a reflected wave from the object in the setup time. At the circuit this time, an alarm is output when no reflected wave from the object is detected in the setup time oppositely. The existence of the reflected wave
Click here to download the full size of the above Circuit.
in the setup time is detected like Ultrasonic Alarm (1) to do this operation. As for the time setting for 555 timer and so on, please refer to Alarm detector of Ultrasonic Alarm (1). The initialization of the circuit is done with transmission timing pulse (A). C to "L", D and F to "H", G to "L" by which D goes to "H". When a reflected wave is detected within the setup time of 555 timer, C goes to "H". With this, the E shifts to "L". When the E goes "L", F shifts "L" and it is held until the next initialization. G shifts to "H" when D goes "L" with the time-out of 555 timer. However, because F is "L", the alarm output H is held on "H" and an alarm signal isn`t output. The initialization of the circuit is done with transmission timing pulse (A). C to "L", D and F to "H", G to "L" by which D goes to "H". When a reflected wave isn`t detected within the setup time of 555 timer, the change of the E doesn`t occur. It is held on "H". When D goes to "L" by the time-out of 555 timer, G shifts to "H". Because F is held on "H", H shifts to "L" and an alarm signal is output. Even if a reflected wave is detected behind the time-out of 555 timer, because D is held on "L" already, the change of the condition of E doesn`t occur. It is held on "H". So, the alarm output is kept. Alarm detecting circuit is composed of SR-FF (The set and reset type flip-flop circuit) and 555 timer. The reset of SR-FF for alarm detecting which is composed of IC8...
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: