This project was inspired by a circuit that a friend of mine, Simon Field, over at Scitoys. com showed me. He had built a very simple transmitter circuit out of a 1Mhz `can` oscillator and a serial connector (see it here ) In his circuit he used a computer to turn the transmitter on and off and to send Morse code. In the United States (and possibl
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y elsewhere) there is a custom at Easter to hide Easter eggs so that the children can search for them. While some of the eggs may in fact be the spawn of chickens, most of the time they are egg shaped plastic carriers into which candy is placed. The kids find the eggs, they extract the candy, and then the kids run around at supersonic velocity on a sugar high all afternoon. Of course sometimes the Easter Bunny forgets where he hid the eggs. Technology to the rescue! This project is an "Emergency Egg Locator Beacon" or EELB for short. The EELB is so small it could easily be embedded in a plastic Easter egg with room left over for candy treats. It emits a customizable message on the AM band that can be picked up by any transistor AM radio, and with simple radio direction finding (RDF) techniques anyone can locate the missing eggs. I was reading the datasheet for the PIC 12F6xx series of microprocessors and noticed that there was a clock mode that fed the system clock, divided by four, out one of the pins. The presumed used is for external synchronization but I had other ideas. Further, the 12F6xx series PICs have an internal oscillator that can run them at 4Mhz. So here we had a computer in an 8 pin dip that could put 1Mhz out on one of its pins. I couldn`t pass that up. The PIC is configured to generate a 1Mhz output on CLKOUT. (pin 3 in the datasheet). That pin drives a 220 ohm resistor which is connected to an LED that is...
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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