Solar Power Center and Solar Charger Circuit

Solar Power Center and Solar Charger Circuit

TLC2272 - 10 Amp out Solar Power Center
The SPC3 is a solar power center, it can handle all of the power functions for a solar charged 12 Volt DC system. The SPC3 contains a 9 amp photovoltaic charge controller, a 10 amp low voltage load disconnect circuit and a built-in white LED array for area illumination. The low voltage disconnect circuit has a load on-off switch, and a battery low voltage indicator. By using the SPC3 as the center of a solar powered device, long battery life is assured. The SPC3 can be used as a self-contained solar lighting system, it is also useful for making solar powered audio and radio devices and much more.
Specifications
Charge Controller Theory
Low Voltage Disconnect Theory
Charge Controller Alignment
Low Voltage Disconnect Alignment
SPC3 Circuit Extensions
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AA Battery Solar Charger

Each of the solar cells develops about 0.5 volts across itself when in full sunlight. The string of 8 solar cells puts out around 4V with no load. When the solar cells are connected to a battery, a current will flow and the battery will charge.
Two versions of the circuit are shown in the schematic, the 8 solar cell panel with a diode is the recommended circuit. The diode prevents the battery from discharging through the cells at night and the 8th cell boosts the voltage up enough to compensate for the voltage drop across the diode. For an 8 solar cell panel, connect jumper J2 and disconnect J1. For a 7 solar cell panel, connect jumper J1 and eliminate SC8 and D1. Typically, the jumpers are not necessary, they are shown in the schematic to illustrate two ways to to build the circuit.
For operation in cloudy weather, it may be useful to add one or two additional solar cells. It is a good idea to temporarily insert an amp (microamp) meter in series with the battery to measure the charging current in various light conditions.
Since solar cells are current-limited devices, it is possible to use the circuit as-is to charge a single battery cell. If one cell is all you ever need to charge, five solar cells and a series diode will be sufficient for the task.
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Solar charger for lead-acid batteries.

This circuit is intended for charging sealed lead-acid batteries with a solar panel in small and portable applications. The customary diode that prevents the battery from discharging through the solar panel has been replaced by a FET-comparator combination. The charger will stop charging once a pre-set voltage (temperature compensated) has been reached, and recommence charging when the voltage has dropped off sufficiently. The load is disconnected when the battery voltage drops below 11V and reconnected when it gets back to 12.5V.
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SOLAR CHARGER

he circuit is a single transistor oscillator called a feedback oscillator, or more accurately a BLOCKING OSCILLATOR. It has 45 turns on the primary and 15 turns on the feedback winding. There is no secondary as the primary produces a high voltage during part of the cycle and this voltage is delivered to the output via a high-speed diode to produce the output. The output voltage consists of high voltage spikes and should not be measured without a load connected to the output. In our case, the load is the battery being charged. The spikes feed into the battery and our prototype delivered 30mA as a starting current and as the battery voltage increased, the charging current dropped to 22mA.
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