The circuit of this device is quite simple: an input circuit filters the signal provided by the antenna to reduce sensibility to other phenomena and protects against over voltages. The four transistors realize a `one-shot` section that is triggered by the input circuit and provides pulses of about 0. 05 seconds to the counter (the 470nF capacitor s
Click here to download the full size of the above Circuit.
ets this time). When the one-shot is triggered it cannot be retriggered for about one second (imposed by the 8 F polarized capacitor) to avoid multiple counts for the same strike. This part is powered by a 6LR61 9V cell and, since the power consumption is lower than 1 A (when no strikes are detected) a single cell will last for some years. The test button allows to check if the battery is still operational: each time it`s pressed the counter should increment and, if hold down, the counter should increment about once per second. The two optocouplers interface the output of the one-shot circuit with the real counter and with the PC. I used a digital 5-digits LCD counter powered by a single LR6 (AA) 1. 5V cell. The power consumption of this counter is about 1. 5 A and the battery life is about one year. This counter also has a reset switch and a piezo speaker that beeps on every operation. Any other counter should work fine (even mechanical ones) but the interface must be modified. The insulation between the counter and the one-shot provided by the optocoupler here is not necessary: I just used an optocoupler to adapt the two different supply voltages (9V and 1. 5V). A transistor and a resistor could work as well. A 6-9V DC counter can be directly connected between the collector of the 2N2904 ant the ground. This circuit is not critical and every semiconductor can be replaced with similar ones. The input circuit uses power...
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: