Matt circuit

 White-light LEDs are finding their way into many markets that incandescent bulbs once served. Flashlights are among the newer applications in which reliability, ruggedness, and ability to control the power draw of the LEDs make these devices attractive. With incandescent bulbs, the power management for the device is a simple on-off switch. However, the LEDs cannot operate directly from the two cells you typically find in most flashlights, because their required voltage is 2.8 to 4V, compared with a battery voltage of 1.8 to 3V. The power management has a further complication because the light output of the LED relates to current, and the LED's characteristics are extremely nonlinear with voltage. One approach to this problem is to boost the power supply with a current limit. A number of devices for LED applications are available; however, their current ratings are typically too low for the 1 to 5W that flashlight applications need. Buck IC Boosts Battery Voltage for White LED Circ...

Description. Here is a simple charger circuit for charging SMF(sealed maintenance free ) batteries.The charger circuit being curernt and voltage regulated,can be safely used to charge SMF batteries of 1.2 AH rating.This circuit was actually designed in response to a request from a reader.With slight modifications you can use it for charging any sort of SMF batteries. The first part of the circuit is the power supply made of transformer T1 and diodes D1&D2.The capacitor C1 filters the rectifier output .The next part is the section comprising of IC1 and Q1 which provides the necessary volatge and current regulation.The diode D3 prevents ther reverse flow of charge from the battery . Circuit diagram with parts list. Notes. Assemble the circuit on a good quality PCB or common board. An ammeter can be conncted in series with the battery to monitor the charging current. Do not short circuit the charging terminals of the circuit.The circuit doesnot have short circuit protection. R4 is ...

Here is a Power Supply Project for Amplifier B circuit. The recommended power supply for amplifier 100W V-MOSFET [1] it is shown in the above figure. Has separated supply for the various stages feed output stage, stage driver, power amplifier and phase protection. Power Supply Project for Amplifier B: Anyone can remove parts or add a power supply for each channel, separating completely the channels between them. Attention should be paid to ground loops. For anyone who does not use the preamplifier circuit and protection can suppress proportional winding. Out Voltages For Power Supply:     +V1=+60V     -V1=-60V     +V2=+12V     -V2=-12V     +V3=+65V     -V3=-65V Power Supply Project Part List :

This circuit is ideal for those with radio transmitting equipment in the control frequency of 35 or 40 MHz, it is a field strength meter, it can check the output power of the transmitters, so you can detect any problems even before the equipment is used. For the test and verification of the correct operation of the transmitter R / C, it must 3 or 4 LEDs lit at a distance of 10 meters.  The length adjustment of the antenna will allow the gauge to operate at a shorter distance.L1 must be initially set to the maximum number of lighting LEDs in a distance of 10 meters or more. Toko coil used in the circuit is no longer manufactured but the coil can be constructed at a frequency of 40Mhz. Test Transmitter for Radio Control Circuit Diagram

Nokia has started rolling out its Windows Phone 8 'Amber' update for its Lumia smartphone lineup, which brings with it a number of major software improvements. Nokia's Amber update builds on Microsoft's most recent Windows Phone 8 update and sees the Finnish firm further outdoing HTC and Samsung with unique Windows Phone features. The most notable new aspect is Amber's added camera features. The update adds Nokia's Pro camera app that debuts on the Lumia 1020 to some of its older phones, including the Lumia 920 and Lumia 925. Nokia's Smart Camera app is also made available to more devices, as the Amber update sees the app arriving in the Windows Store. Detailing the Smart Camera app on its blog, Nokia said, "The app brings a slew of different options – use Best Shot to find the sharpest image from a series of ten; combine several shots of people in movement into one with Action Shot; heighten the appearance of speed by blurring the background with Motio...

How do you want to have your wipers become more intelligent? In this way, they could remember how frequent you need to use them. But of course, this will need the help of an ATmega8L micro-controller. When you need to activate the wiper, you just press the button and it will run in one course. There is a 45 seconds waiting time that if you do not press the button, it will go on standby while telling itself that only one course is needed. The system will activate the wiper again if the button is pressed before 45 seconds. The good thing is that it will remember the interval when you pressed the button.

Schematic diagram of switching power supply for color television , which can used on a particular color TV, how it works using the switching transformer and switching transistors. At first voltage AC220V entry through the capacitor and resistor, and then immediately rectified AC voltage by 4 diodes and capacitor given on each diode. After a DC voltage then passes through a capacitor elco in parallel , and into the circuit and the voltage is lowered by the switching transformer. After the voltage is lowered and then was rectified and filtered again in the after circuit, the output voltage is set up on their own. For output +5V and +12V using ic stabilization 7805 and 7812. To use circuit switching power supply can be used on the same output voltage. If the circuit is working you should never ever touch the live area , because of the high-voltage section. And if the circuit has stopped working , do not forget to remove the voltage on the capacitor electrolyte, by linking the two legs to ...

Extension for LiPo Charger Project Image The ‘Simple LiPo Charger’ published in Elektor Electronics April 2005 is a small and handy circuit that allows you to quickly charge two or three LiPo cells. Especially in the model construction world are LiPo batteries used a lot these days, particularly model aeroplanes.  It is usual to use a series connection of three cells with these models. Since working with these model aeroplanes usually happens in the field, it would be nice if the batteries could be charged from a car battery. We therefore designed a voltage converter for the LiPo charger concerned, which makes it possible to charge three cells in series. The voltage per cell increases while charging to a value of about 4.2 V, which gives a total voltage of 12.6 V. The converter, therefore, raises the 12-V voltage from the car battery to 16.5 V, from which the LiPo charger can be powered.  Extension for LiPo Charger Circuit Diagram A step-up controller type MAX1771 in combina...

        Samsung has announced a new S Pen stylus for its line of Galaxy Note. New pen was called Advanced S Pen and, in the words Samsung, twice more sensitive than conventional digital pen in Samsung Galaxy Note 4. As the company Advanced S Pen stylus has received a number of new opportunities, become more convenient for drawing and writing (even allows you to save virtually unchanged handwriting) can take screenshots and get more levels of pressure sensitivity. Moreover, a stylus detects the speed, tilting and rotating. In addition, Samsung has released an SDK for developers that will enable them to create applications for the stylus. New electronic pen Advanced S Pen can work with smartphones Samsung Galaxy Note 4 and Galaxy Note Edge. Does not specify whether it is included in the package, or it can be purchased separately.

BlackBerry has officially announced its latest Qwerty smartphone, the BlackBerry 9720.The new device, which runs BlackBerry 7.1 OS, will be available in the "coming weeks" from retailers and carriers in Asia, EMEA and Latin America. BlackBerry has not released pricing yet, however, the devices has drawn comparisons to its BlackBerry 10 OS Qwerty, the Q5, with suggestions it would be a low-cost number designed for emerging markets. The official specs appear to back that up. "It's perfect for customers upgrading from a feature phone or entry-level Android or Windows Phone device, as well as existing BlackBerry smartphone customers, that want a richer experience and jump up in style and performance," Carlo Chiarello, executive vice president for products at BlackBerry, said in a statement. The 9720 comes in five colours and sports a 2.8 inch touchscreen and trackpad as well as the Qwerty keyboard. BlackBerry claims a battery life of seven hours talk time. The 512M...

Troubleshooting Tips for Electrical /Electronic Maintenance This section concentrates on the problems plaguing brand-new systems. In this case, failure modes are generally not of the aging kind, but are related to mistakes in design and assembly caused by human beings. Wiring problems In this case, bad connections are usually due to assembly error, such as connection to the wrong point or poor connector fabrication. Shorted failures are also seen, but usually involve misconnections (conductors inadvertently attached to grounding points) or wires pinched under box covers. Another wiring-related problem seen in new systems is that of electrostatic or electromagnetic interference between different circuits by way of close wiring proximity. This kind of problem is easily created by routing sets of wires too close to each other (especially routing signal cables close to power conductors), and tends to be very difficult to identify and locate with test equipment. Power supply problems Blown...

This is a dual-output switch mode power supply reference design based on the MAX17116. The part and reference circuit can provide both negative and positive supplies to AMOLED displays. [via]   The MAX17116 includes two current-mode 1.4MHz switch mode power-supply (SMPS) regulators for active-matrix organic light-emitting diode (AMOLED) displays. The positive supply is provided by a step-up regulator with a synchronous rectifier. The negative supply is provided by an inverting regulator with a synchronous rectifier.[ ]

The AM aircraft band at 118 to 136 MHz is used in this converter design as an IF output. The second harmonic of the 55-MHz crystal (110 MHz) mixes with the shortwave input of 8 to 36 MHz. An NE602 1C is used for the mixer. Sensitivity is about 3 micV. If desired, a crystal tuning circuit for fine tuning can be obtained using a varact or. Shortwave Converters for Scanners Schematic