Rongge

A common problem when an AC mains adapter is used to power a USB device is that the voltage does not match the nominal 5 V specified by the USB standard. The circuit shown here accepts an input voltage in the range of 4-9 V and converts it into a 6-V output voltage, which is then stabilized to a clean 5-V level by a series regulator. The combined boost/buck converter used here operates on the SEPIC principle. That principle is quite similar to the operating principle of the Cuk converter, but without the disadvantage of a negative output voltage.   Circuit diagram :   Stable USB Power Supply Circuit Diagram   The circuit is built around a MAX668, which is intended to be used as a controller for boost converters. The difference between a SEPIC converter and a standard boost (step-up) converter is that the former type has an additional capacitor (in this case C2) and a second inductor (in this case, the secondary winding of transformer L1). If C2 is replaced by a wire bridge and ...

One tool that I’ve been missing at my lab at home is function generator. They tend to be a bit expensive, so I haven’t bought one. I thought this might be a good opportunity to try and make one myself. I found a pretty common DDS (direct digital synthesis) chip, called AD9833. Then just strap a USB-enabled AVR micro there and maybe some analog electronics. This board doesn’t do any of the special analog magic to allow for variable amplitude or offset for the signal. The output is fixed to 0-4v. I’m planning to make another completely analog board for adjusting amplitude and offset. [ ]

When turning a computer on and off, various peripherals (such as printers, screen, scanner, etc.) often have to be turned on and off as well. By using the 5-V supply voltage from the USB interface on the PC, all these peripherals can easily be switched on and off at the same time as the PC. This principle can also be used with other appliances that have a USB interface (such as modern TVs and radios).  USB Standby Killer Circuit Diagram : This so-called ‘USB-standby-killer’ can be realised with just 5 components. The USB output voltage provides for the activation of the triac-opto driver (MOC3043) which has zero-crossing detection. This, in turn, drives the TRIAC, type BT126.  The circuit shown is used by the author for switching loads with a total power of about 150 W and is protected with a 1-A fuse. The circuit can easily handle much larger loads however. In that case and/or when using a very inductive load a so-called snub-ber network is required across the triac. The val...

USB cable consists of 4 wires plus a conductor wire wrapping, such as the protectors are usually found in the audio cable. Cable number 1 is used to channel resources to the voltage of 5 volts, if necessary USB devices may draw power from this line and should not exceed 100 mA. Computer equipped with USB capability, is required to provide power at 100 mA for this purpose. USB devices that require more power than the aforementioned provisions, must provide their own resources for the purposes work equipment. The USB cable signals Number 4 is the ground cable as a back channel source voltage of 5 volts. Cable number 2 and number 3 is used for signal transmission. No. 2 cable and cable called D-3 numbers called D, the voltage on the two channels is changed between 0 Volt and 3.3 Volt. Digital signal is sent through the two channels are said to be 'difference signal', which means that the signal digital '0 'or '1' is not declared to the magnitude of the voltage on ...

This is a simple project of USB Powered Audio Power Amplifier Circuit Diagram. This USB Powered Audio Power Amplifier Circuit Diagram of multimedia speakers for PCs has single-chip-based design, low-voltage power supply, compatibility with USB power, easy heat-sinking, low cost, high flexibility and wide temperature tolerance. At the heart of the circuit is IC TDA2822M. This IC is, in fact, mono-lithic type in 8-lead mini DIP package. It is intended for use as a dual audio power amplifier in battery-powered sound players. Specifications of TDA2822M are low quiescent current, low crossover distortion, supply voltage down to 1.8 volts and minimum output power of around 450 mW/channel with 4-ohm loudspeaker at 5V DC supply input.  An ideal power amplifier can be simply defined as a circuit that can deliver audio power into external loads without generating significant signal distortion and without consuming excessive quiescent current. This circuit is powered by 5V DC supply available...

This is a very simple dual USB power supply controller using the isl6185 USB power controller family. Dual USB power supply electronic project that provides fully independent overcurrent (OC) fault protection for two or more USB ports. Dual USB Power Supply Controller Circuit Diagram: This product family consists of sixteen individual functional product variants and three package options and is operation rated for a nominal +2.5V to +5V range and specified over the full commercial and industrial temperature ranges. Each ISL6185 type incorporates in a single package two 71mΩ P-channel MOSFET power switches for power control and features internal current monitoring, accurate current limiting and current limited delay to turn-off for system supply protection along with control and communication I/O. The ISL6185 family offers product variants with specified continuous output current levels of 0.6A, 1.1A, 1.5A or 1.8A. Due to all integrated features this power supply circuit is very easy to...

This project is a remake of an old discolights pod. Original 24V 5W bulbs are changed to 230V 40W with E14 thread. Original driver board has non-typical signal input. This driver is based on the FT245RL chip, a USB-LPT converter – so you can use it with PC applications such as discolitez. Low voltage part is supplied directly from the USB so there is no need to to use any transformer…   Device uses a MOC3041 optotriac and a BT136 triac in a standard application to drive bulbs. Note if you want to use stronger bulbs, like 100W or more, you need to use some little radiators to cool down the triacs. There are 4 channels, 3 are used for bulbs and 4th is used as an extra 230V output – in this case for a mini strobe. You can find 4 goldpins on board, these are a 4 extra output channels – so you can expand device to another optotriacs and triacs to use 4 more 230V devices. To your own safety, use a proper fuse, and remember that device works on a 230V potential. You can use it with 110V d...

In this article I will discuss my own experiences about designing a USB sound card, which is the USBDAC. DAC is an acronym for Digital-to-Analog Converter because in a sound card, digital data representing the sound is converted into analog voltage that moves the speaker cone. My device is loosely based on the PCM2706 reference design. I will not go through the tecnical details but instead concentrate on my own experiences in the design of the device. This is to keep people not familiar with electronics, as well as newcomers to electronics design, interested. You will see that one working product is the result of many failed prototypes.

Eridani is a LM3S3651 based general purpose development board with USB Host/Device/OTG. You can buy one here. This documentation should help you use it effectively. All of the details on how to setup toolchains for this board are filed under getting started.

This circuit is a simple test of USB ports, it is a circuit very useful for anyone working in the field of computer science. To be "stuck" in the PC USB port or an information display Notebook USB device not recognized, just after the yellow LED flashes 3 times, and since it is not a normal USB device, the connection is not established, and micro displays an error message. Tester for USB communication ports Circuit Diagram List of Components 1 Red LED 1 Led Yellow 1 Green LED 3 per 1k 1/8W Resistors 1 USB connector male Simple Test for USB communication ports Indications of LEDs when lit: Red - Polarization USB port was mounted inverted Yellow - Wire USB port data were linked inverted All Deleted - No power to the USB port Green and yellow lights flashing 3 times when turned on - Normal Operation