An old nonfunctional DVD player donated by the Engineering Department was gutted to provide an appropriate enclosure for the audio amplifier. To mount the nearly 16 lb toroidal transformer and 2in diameter filter capacitors, various sheet metal braces were machined in the shop. The 25A rectifier bridge was bolted to a heatsink attached to the bott
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om of the enclosure, and a temporary brace was attached to hold the mains power switch and fuse holder. The current state of the amplifier construction process is shown in Figure 1. Because the +12V, -12V, and +5V regulators can only take a maximum of 30V at the input, a smaller 24VCT 700mA frame-type transformer was also mounted to power the lower voltage circuitry (preamplifiers, delay circuitry, output relay controllers). The delay circuit originally presented was modified to allow for an adjustable delay setting via a potentiometer, and a LM311 comparator was included to make a definite logic level transition. The modified power supply circuit is shown below in Figure 2, and the assembled delay/voltage regulation circuit is shown in Figure 3. Upon turn on, the delay circuit and main high current power supply worked correctly. Mains unloaded voltage was measured at +/-34VDC, and the smaller power supply produced as expected +12V, -12V, and +5V, as well as the 0-5V logic level delay signal. Since the reservoir capacitance of the small power supply is only 1000uF per rail, local capacitative decoupling will be important for clean voltage levels in the preamplifier circuitry. To prevent ground loops, the center taps from the transformers are not connected directly to the chassis, but will be linked to the chassis through the circuitry at the point where the audio input connector grounds are attached to the case. This...
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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