Flicker Free Automatic Light


When we use Triac and LDR to make Automatic Lights, a major problem arises . Lamp starts flickering during the light transition period in the  evening and morning. Lamp fully turns on only when there is complete darkness and turns off only when day light is full. This simple design solves the problem. Light instantly turns on / off without any flickering. You can drive CFL, LED bulb etc which turns on automatically around 6 pm and turns off around 6 am. See the simple design. Continue reading “Flicker Free Automatic Light”

How to select resistor for 1 watt LED


1 Watt LEDs are widely used in Emergency lights and LED lights. Most of the circuits use 4 volt battery having 0.5 to 4 Ah capacity. The 1 watt LED is rated 3.6 volts maximum so we need the correct value resistor for LED to get maximum brightness. Let us see how the LED resistor value is determined.
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Automatic Battery Charger


Here is an efficient battery charger for Car battery and Inverter battery. It quick charges the battery with 5 Ampere current and cut off charging when the battery attains 13.8 V which is the full charge condition of the Lead Acid battery. Red LED indicates charging process while Green LED indicates full charge and charger cut off status.
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How to connect Relay with NPN and PNP transistors


Transistor is used to drive relay to connect AC loads. For efficient working, it is important to connect the relay correctly in NPN and PNP transistors. See the way of connection. Continue reading “How to connect Relay with NPN and PNP transistors”

How to Convert SMPS to Bench Power supply cum charger



Don’t throw away the SMPS power supply when the Computer damges. SMPS is a high current device that gives different regulated voltages from the output wires. It has numerous wires to give different voltages . So you can make a good Multi voltage power supply for the Projects or use as battery charger for different types of batteries. It has total isolation from Mains and output is safe DC.
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Power Supply Box


This Power supply box can be used to interface with the High current Bench power supply made from the SMPS of Computer. The Power supply box has a DC-DC Converter cum Booster module, A Volt Meter and an Ammeter to show output voltage and current consumed by the load. Continue reading “Power Supply Box”