My Light Diagram

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...

A partial solution to quietening noisy PCs can be to reduce the speed of internal cooling fans. Low-cost fan speed controllers are available, but they often employ inefficient, heat-generating linear regulators and contain no temperature feedback mechanism. This idea makes use of a readily available, cheap in-car mobile phone charger. The majority of these use common circuitry and require only minor modifications to operate as efficient fan speed controllers complete with temperature feedback. Most in-car chargers are based on the well-known MC34063 DC-DC switchmode IC. When used for charging mobile phones, the open-circuit output voltage is typically set to between 7V and 9V. This is achieved with a simple voltage divider across the output, the centre point of which connects to the feedback input (pin 5) of the MC34063. To make the output voltage var-iable with air temperature, first replace the upper resistor of the divider with a 4.7kΩ resistor in series with a 4.7kΩ trimpot. The lo...

STV9380 and STV9381 is a vertical ic-out which very efficient, so it does not require cooling (heat sink) as the vertical ic is generally. This circuit works the same way as most other vertical ic, except at the amplifier end only. Amplifier section works at the end of class D (this is different to the generally vertical ic which working on a class AB).  STV9380 and STV9381 Vertical signal input by the "MODULATOR" changed its form to first become a form of "pulses" box before it is reinforced by the end of the transistor. Here transistor "amplifier end" work as like "switching transistor". Output result is a strengthening of which pulses of the box is then returned into regular shapes such as vertical signal using an LC fillter (capacitor and filter coil) . Requires IC supply voltage (+) 16V and (-) 16V STV9380 is able to produce pulses of the vertical 2.5 APP (Ampere pitch to peak) and STV9381 3 APP. STV9380 and STV9381 Vertical efficient