Here is a crude but efficient charger for Lead Acid Battery. It uses a 12 volt car bulb as current regulator and charge status indicator. The brightness of the bulb indicates how much charge is flowing into the battery. When the battery becomes fully charged, lamp turns off. If the lamp is staying on with full brightness for more than 30 minutes, it indicates that the battery is dead and is not accepting charge.
This is the simple way to connect an LED in the Mains to use it as a pilot lamp. It takes little current compared to a neon lamp. It can power low efficiency as well as high efficiency LEDs including White and Blue LEDs.
Low cost Pilot Lamp
Here is an Energy saving battery charger. It harvests solar energy to replenish 12 volt Inverter battery. It has auto cut off facility to stop charging when the battery attains full charge. The charger uses a 24 volt solar panel as input
Solar charger with Cut off
Here is a circuit to charge Lead Acid or NiCd batteries using solar energy. The circuit harvests solar energy to charge a 6 volt 4.5 Ah rechargeable battery for various applications. The charger has Voltage and Current regulation and Over voltage cut off facilities.
This Solar based LED flasher can Alert vehicles in heavy traffic areas or places where road work is going on. It is fully automatic and turns on in the evening. During day time it remains off and charge the battery using solar energy
This simple circuit tells you about status of phone such as Line OK, Dialing and Call attended. It also has a lock facility to block outgoing calls keeping the incoming calls as usual. This prevents misuse of telephone. The circuit uses only a few components to do all these jobs
Telephone Status Indicator
Here is a White LED Lamp that turns on when the telephone rings. The cool white light helps to locate the phone in darkness and also helps to note the message or telephone number. The lamp remains on for three minutes then turns off
Power factor correction is the method to reduce the lagging power factor in inductive loads by fixing a high value capacitor across the phase and neutral close to the load. When the Voltage and Current are in phase with each other in an AC circuit, the energy from the source is fully converted into another form to drive the load and in this case power factor is in unity. When the power factor drops, the system becomes less efficient. As a rule a drop from unity to 0.9 in the power factor increases the current requirement to 15% or more.
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Power Factor Correction
Here is the simple solution to make an automatic solar powered lamp. It automatically switches on two high power White LEDs in the evening and stays on for 6 hours using a 6 volt 4.5 Ah rechargeable battery.
Here is a High power White LED lamp that gives ample light in a room. It is an energy saving lamp and consumes very little power to give sufficient light. The lamp is directly powered from AC hence it is compact and easy to fix inside the switch board box.