We all use LED Bulbs to save energy. It is available in 3W, 5W,7W,9W,15,18W etc . What this Watt indicates? Is its Power output similar to CFL, Tube light etc or light intensity similar to CFL or Tube light? If you consider the specified watts as the real output, then it is a mistake because the Capacitor power supply used in LED bulbs cannot give the specified output. For example, a 9 Watt LED bulb shows that it is only 3.9 W both in theoretical calculation and in power measurements. Let us hack one LED Bulb to see how it is behaving.
Continue reading “Reality in LED Bulbs. Home Utility Circuit. 25”
Transformer is used to convert high volt AC to low volt AC (Step down) or low volt AC to high volt AC (Step up). So step-down transformer is generally used to convert 230 Volt AC to low volt AC which can be used to make a DC power supply after rectification and smoothing. But a Non polarized capacitor can act like a transformer to step down the high volt AC to low volt AC. Say, 230 V AC to 40 VAC. Let us see how the capacitor is doing this.
Continue reading “How Capacitor functions as a Transformer? Design Note 42”
To reduce size, and cost, Transformer less power supply is now used. If it is a well regulated SMPS power supply, output will be stable. But simple Transformer less power supply is not ideal for many circuits as observed in my experience. I have designed different types of Transformer less power supply but none of them is showing good performance. It can be used to power simple circuits like LED lighting. If sensitive semiconductors are present in the circuit, this kind of power supply creates many problems including erratic response. This is very high in sensor based circuits and oscillators. So to get a perfect output voltage, it is ideal to use a Transformer based power supply or SMPS. These are the problems I noticed in the Transformer less power supply.
Continue reading “Transformer less Power supply Problems. Design Note 39”
It was a big problem in my house that, sometimes the Water heater left on for many hours after the use. It has a Thermostat to cut off but when the water cools, again it switches on. This caused a hike in electricity bill. Finally I found a solution. Just connected a Timer based alarm with the heater AC socket so that it will also switches on when the heater turns on. After 30 minute, it gives a loud alarm to remind that the heater is On. Alarm continues for another 30 minutes or till the heater is switched off.
Continue reading “Alarm for Water Heater”
To reduce cost and size, Transformerless power supply is now widely used which uses an X-Rated Non-Polarized capacitor to reduce 230 volt AC to low volt AC. It is then rectified and used as low volt DC. But unlike the Transformer based power supply, the transformerless power supply has many disadvantages
Continue reading “Drawbacks of Transformerless power supply”
This Mini portable White LED Emergency Lamp is highly useful in the event of an unexpected power failure. It gives sufficient light in the room. It is too small and is an ideal utility gadget for the use in camp places during journey. It can be plugged in just like a Mobile charger.
Continue reading “Plug in Emergency Lamp. Utility Gadgets 1”
This simple 1 watt LED lamp can give light equal to 11 watt CFL. It is directly powered from AC using capacitor power supply. The light from this 30 LED lamp can very well illuminate the room and is suitable for reading purpose also.
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Continue reading “Extra Bright LED Lamp”