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Showing posts with the label source

Efficient Current Source for High power LEDs

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To get the maximum brightness and working life out of a high-power LED, it needs to be driven at the optimum specified current. Allowing the current to exceed the permitted value is to be avoided at all costs, since it will severely affect the life of the device. A power supply or a battery with a small current-limiting resistor is not really an ideal solution, since not only is energy wasted in heating the resistor, but, if a small value is chosen to minimise this wastage, small changes in the applied voltage will lead to large changes in the current that flows. It is well known that LEDs have a small dynamic resistance in the neighbourhood of their optimal operating point. We will there fore need more in the way of electronics than a simple series resistor to meet our requirements.   Circuit diagram: Efficient Current Source for High-power LEDs Circuit Diagram   The most direct way to provide a highly constant current in the face of relatively small changes in supply voltage i...

12 Vdc Battery Operated 120 Vac Power source Circuit Diagram

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This is the Simple 12 Vdc Battery Operated 120 Vac Power source Circuit Diagram. This simple 1 20 V: 24 V, center-tapped control transformer and four additional components can do the job. This circuit outputs a clean 200 V pk-pk square wave at 60 Hz and can supply up to 20 W. The circuit is self-starting and free-running. If Q1 is faster and has a higher gain than Q2, it will tum on first when you apply the input power and will hold Q2 off. Simple 12 Vdc Battery Operated 120 Vac Power source Circuit Diagram Load current and transformer magnetizing current then flows in the upper half of the primary winding, and auto transformer action supplies the base drive until the transformer saturates. When that action occurs, Q1 loses its base drive. As it turns off, the transformer voltages reverse, turning Q2 on and repeating the cycle. The output frequency depends on the transformer iron and input voltage, but not on the load. The frequency will generally range between 50 to 60 Hz wit...

Universal battery charger with 12V source voltage

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In this post I will share about using Accu source to charge batteries that can be used on any mobile brand, or can be called universal phone battery charger. Because the battery charger using a source of 12V, the charge accumulator can also be used in cars and others. This will out charger circuit voltage of 5 volts DC, with input from at least 6 volt battery, and voltage inputs that have been tried till with 15 volts (more than it has not been tried, because the battery that tie the maximum output voltage is only 13.8 volts).