There are two main types: the most common is the Wein Bridge oscillator variety, which has low distortion, but offers only sinewave output and can suffer from amplitude bounce as you change frequency. The type which offers greater versatility of waveform and frequency range, the usual function generator type, typically lack stability and accuracy. This unit meets all these requirements, and is small - fits in the palm of your
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hand - and is battery operated. It also has no "front panel" - you control it from a PC or computer terminal. The generators are quite inexpensive to build - just two or three ICs and a couple of transistors. One of the ICs is an AVR RISC microcontroller - inexpensive, and quite powerful. It operates in an unusual manner, using a Direct Digital Synthesis (DDS) technique developed by Jesper Hansen to create very accurate signals. Some of the features of the Function Generator are: Many of the parameters, such as frequency range, step size and frequency response can be tailored to suit other applications. The picture below, of the simple PC control panel for the generator, shows a 4MHz version in use, with an upper limit of about 133 kHz. The absolute upper frequency limit of any generator using this microcontroller technique is set by the maximum clock frequency (currently 16 MHz). The upper limit of the generator is thus about 500 kHz. There is no lower limit. A 12. 8MHz version for use as an Exciter for the Amateur LF bands is also available. Power for the unit comes from a tiny 5V regulator, which runs from a DC supply (battery or AC adaptor) with an output of between 6V and 15V. The supply is reverse voltage protected. The RS232 communications with the PC uses simple transistor level shifters. The transmit signal from the microcontroller requires a negative voltage supply, and for simplicity, this voltage is derived...
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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