CirKits

	Charge Controller/Low Voltage Disconnect Alignment

The equipment required for alignment of this circuit consists of a multi-meter,
a charged 12 Volt lead acid battery, a 0-16V DC variable voltage power supply
with a 10 ohm 25 watt resistor in series with the positive lead to limit the
current and a load such as a #1815 12V miniature automotive light bulb.  Some
small alligator clips may also be handy for making test connections.  The
bulb should be rated at about 100ma of current.  A word of caution is in order,
when dealing with circuits involving potentially high battery currents, the
circuit should be placed on an insulating surface for testing and all wiring
should be insulated, this lessens the chance of creating a short circuit and
burning things up.  Be sure not to reverse the polarity of the battery wires,
doing so may damage the circuit.  The voltages in this circuit present no
shock hazard but the currents present a potential burn hazard.  Be sure to
observe correct polarity when connecting the battery and DC power supply.

Low Voltage Battery Disconnect Alignment

Connect the power supply to the board's battery input terminals and the light
bulb to the load output terminals.  Turn potentiometer R22 fully clockwise.
Set the variable voltage supply to 11 volts or whatever your turnoff voltage
will be.  Turn the LVD switch on, the light should go on.  Slowly adjust R22
counter clockwise until the light goes out.  Test the setting by increasing
the supply voltage to 13V, turning the light on, then turning the voltage
down until the light goes out, R22 may need to be fine tuned to get the
shutoff point exactly where you want it.

Solar Charge Controller Alignment

The charge controller alignment begins with setting the low and high points
that the battery will alternate between when it is fully charged.  Set the
current limited variable voltage supply to 17V and connect it to the solar
panel input.  Connect a fully charged battery to the battery terminals and
connect the volt meter across the battery.  The battery must be at the full
charge point for the alignment to work.  Turn R13 fully counter-clockwise.
Turn R11 and R12 fully clockwise, the Red LED should be on.  Turn R12
counter-clockwise until both LEDs turn on.  Turn R11 counter-clockwise until
the LEDs alternate a few times per second.  Observe the battery voltage and
adjust R12 and R11 the same direction in equal amounts until the battery
voltage is at the desired fully charged voltage.  Clockwise sets the voltage
higer and counter-clockwise sets it lower.  The LEDs should alternate a few
times per second when they are set right.  Richard Perez from Home Power
Magazine recommends setting the charge point to 13.8 volts for sealed
gell-cells and to 14.5 volts for flooded cell (wet) lead-acid batteries when
using solar power.  The voltages should be lower for applications with
continuous input power.  If the battery voltage drops too slowly and does not
track R11 and R12 during the test, it may be helpful to connect a small 12V
lamp directly across the battery during this part of the test, the bulb will
cause the battery to discharge faster.  It may also help to adjust the voltage
of the variable supply, this will vary the charging current and duty cycle of
the flip-flop.  A final adjustment should be made with the circuit connected
to a battery and a solar panel that is exposed to the sun.

The last alignment step sets the charge controller turn-on voltage with R13.
The battery and power supply should remain connected as they were in the
previous step.  Adjust the variable supply to 14.5 volts.  Adjust R13 clockwise
until the LEDs turn off.  Slowly adjust R13 counter-clockwise until the LEDs
just turn on or start to blink.  Now adjust R13 another 1/4 turn
counter-clockwise.  This completes the alignment of the charge controller.
If you have problems aligning the kit, send it to CirKits with a check for
$10 (in the US) and we will align and return the unit.  Please specify the
type of battery you will be using such as gell cell or wet cell, or tell us
what voltage you would like the batteries to top out at.