The Universal Serial Bus (USB) has become a popular method of connecting computer peripherals. The original USB 1. 1 specification limited data rates to about 12 Mbits/sec. The updated USB 2. 0 spec increases those rates to up to 480 Mbit/sec. Both versions of USB can provide DC power to peripheral devices. This power form is the subject of this pag
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e. USB is less expensive than FireWire because a dedicated FireWire controller chip set isn`t needed. The computer`s CPU does the USB controller function in software. Under good conditions, USB can work nearly as well as FireWire, but at sustained high data rates, USB will sag under the strain. FireWire tends to work better but cost more therefore USB 2. 0 is more common, especially in lower end hardware. The USB 2. 0 specification can be found at the link. For reference, a link to the USB 1. 1 specification can be found at the bottom of the referenced page. Besides a data link, USB provides 5 +/- 0. 25 volts to power an otherwise unpowered device or charge a battery in a self powered device. A USB controller or hub is required to power one unit load (100 mA, a low power load). It can optionally power up to 5 unit loads (500 mA, a high power load). The spec is silent about intermediate loads, so I assume that the sources deal with just the two cases. Either a load is low power (like a keyboard or a mouse) or high power (like an iPod or PDA). Each USB device requires some way to power it. The device may run entirely from the USB port such as a jump drive does. Some devices have internal batteries that need charging. In any event, as the number of USB devices that I`ve collected has increased, management of an individual charger for each device is becoming a pain in the backside. Since the USB power form specification is a...
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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