Alarm for Water Heater


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 causes 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. So that alarm reminds to switch off the water heater. This can be used for Electric Iron also.

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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”

Simple Tranformerless Power supply


It is very easy to convert 220 Volt AC to DC for powering electronic circuits. Any DC voltage from 3 volt to 36 volt can be generated from 220 volt AC using appropriate value of X rated capacitor and Zener diodes. The X rated capacitor drops 220 V AC to low volt AC. This can be rectified to DC by a Rectifier diode and smoothed by a Filter capacitor. By selecting a required value Zener, regulated DC can be obtained. But the only drawback of the Tranformerless power supply is its low current, so only light loads can be used. Here explains the design of a 4.7 Volt 4.6 Milli Ampere Tranformerless power supply to power PIR sensor .

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AC Powered PIR Light


A Simple design of PIR Light using Tranformerless Power Supply and Triac for driving the load. Too compact and can be enclosed in a small case. The light turns on when the PIR sensor detects human movement and turns off after the preset time. Re triggers in another movement. Its range is 30 cm to 10 meters and time delay, 30 seconds to 3 minutes both can be adjusted using the presets in the PIR sensor Module.

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Fast Charger for Car battery



Here is an efficient Car battery charger for fast charging the Car battery. It is a 5 Ampere charger with Digital Volt and Ampere Meter to display the charging voltage and current. Since the charger provides maximum 5 Amps current, battery can take high current it needs to charge very fast. As the charging process completes, current flow reduces to zero and will be displayed in the meter. So it is easy to confirm whether the battery is fully charged or not.
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How to connect Panel Meter in Battery Charger



Digital Volt Ampere Meters are now available which can be used in Battery chargers to monitor voltage and current. One section of the Meter displays 0 to 100 V DC and the second section displays current 0 to 10 Amperes. The Meter works off 4 to 30 V DC. Let us see how it can be used in a charger….
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Automatic Car Battery Charger


This 5 Amps charger automatically stops charging when the terminal voltage of battery rises to 13.7 V thus preventing over charging. If the battery voltage drops below 11 V, Charger turns on and starts charging. Check it……….
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