Regulated Power Supply. Design Note 33

Most of the CMOS circuits need a well regulated power supply for proper working. Regulated power supply is the DC source that gives constant Voltage and Current in its output irrespective of the input changes. Various types of power regulation methods are available which depends on the use and type of the circuit. Here explains three Regulated power supply designs.
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Battery Chargers. Design Note 32

IMAGEPresenting here three circuits to make efficient Battery chargers. The 12 volt Lead Acid Car battery requires high current for fast charging. If we provide high current, the battery will charge within 1-2 hours fully. Usually a Lead Acid battery takes high current initially, which drops to 500 mA or less after 10-20 minutes. As a rule, it is advisable to charge the battery with a current that is 10 times lesser than the battery capacity. The Car battery is 32 Amps or 45 Amps so it requires 3.2 Ampere and 4.5 Ampere current respectively. So the charger should provide 14 volts with a current of 5 Amperes.

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Smart Solar Charger. Design Note 31

IMAGEYou can make a simple Current regulated Charger for your Solar Panel. It safely charges the 12 volt battery with a constant current of 540 Milli Amperes. It needs only a few components and can be hooked between the Solar panel and the battery. It also has an LED charge indicator and a revere polarity protection diode.
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RF Detector. Design Note 29

This is my latest Circuit published in the June 2015 issue of Electronics For You Magazine. It is a device that measures the intensity of Radiation in the room. Lot of Electromagnetic radiations are present in home emitting from WiFi, Mobile phone, Computer and other electronic devices. So the device shows the level of RF energy in a meter. Meter shows full deflection when the RF radiation is very high. It also gives a simultaneous LED indication.


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How to Protect Solar Inverter Battery .Design Note 28

One of the main problems in Solar Inverter system is poor charging of Battery during rainy seasons and in cloudy days. The high current Tubular battery requires more than 1 Ampere current for proper charging. To solve this problem, I have designed a” Hybrid Solar charger” and the circuit was published in Electronics for You magazine September 2013 issue. So the charger has two sides. One side gets power from Solar panel and the other side from a Step-down transformer. If the voltage from Solar panel reduces below 9 volts, the charger shifts to AC mode and battery charges via the current from transformer.
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Solar Power for Lighting. Design Note 27

Solar panelYou can use a Solar panel to power electrical appliances directly during day time if the Sunlight is very good, direct and continuous. So you have to install a Solar panel in a well lit area over the roof top in the East- West direction with a slight angle facing the Solar panel to the sky. So when the solar panel gets sunlight, it generates voltage and current which flows through the cables connected to it. You can have two options. The current can be stored in a battery to power the appliances at night through an Inverter or you can directly use the solar power using an Inverter without battery. Solar power is DC voltage and the Inverter converts this DC into AC to power the AC appliances. So let us see the requirements.
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Lightning Arrester. Design Note 26

GDT H 230 LB
Various kinds of Lightning arrester circuits are available, but here describes one with Multi-level protection so any one of the component may be damaged if a strong lightning occurs. Thus it leaves the gadget without damage. Usually one Surge protector like MOV, GDT, Bidirectional Diode etc is used in surge protector circuit. But here a combination of all the three is used to give multi level protection. The circuit can be hooked up in Telephones, Cable TV lines, Modem, Dish antenna cable etc.
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