GadgetPower GP1200 Owner's Handbook Manual - Page 9

Browse online or download pdf Owner's Handbook Manual for Inverter GadgetPower GP1200. GadgetPower GP1200 12 pages. Robotic solar generator

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TRACKING

Once calibrated, the device follows the sun – or 'tracks' it – using two different meth-

ods: one to track the sun's horizontal position, and another to track its semi-vertical.

Two methods are required because the sun behaves differently on each axis. The sun's

horizontal motion is in one direction only, and it is identical every day – it appears to

move from east to west at a rate of 1 degree every 4 minutes – therefore the sun's

motion on this axis is tracked by simply rotating the device's panel westward at a

matching rate (and not, it should be noted, by continually monitoring the sun's position

and manoeuvring the panel accordingly, as this is unnecessary once the mechanism has

been calibrated). However – and although the sun's semi-vertical motion is somewhat

slower, just one degree every 7.5 minutes – its motion on this axis is more complex: 1)

it appears to move in two directions in one day, first up, then down; 2) the extent of

this motion varies throughout the year – in the UK, for example, the sun mid-winter rises

to a maximum height of just 15.5 degrees above the horizon, yet mid-summer it rises

four times higher, to 62.45 degrees above the horizon. To accommodate this complex

behaviour, the sun's semi-vertical position is tracked by fully recalibrating along this axis

at 60 minute intervals.

ENVIRONMENT MONITORING

The device is designed deliberately not to respond to every individual change in condi-

tions: a cloud, for example, temporarily obscuring the sun will not immediately cause

the device to retreat to its Standby Position. Instead, the device's behaviour – once

calibrated and while tracking – is determined by measuring the AVERAGE amount of light

falling on its solar panel over a four-minute period (the period between each incremental,

westward 'tick' of its rotating Head). By comparing that measurement to a similar meas-

urement performed on the internal battery (a measurement which also determines the

colour displayed by the device's Indicator Light), the mechanism can decide whether to

continue or to discontinue tracking: if it is anticipated that, by continuing to track, there

will be a benefit to the battery – which is all that matters to the device – then it contin-

ues to track, otherwise the device's panel is returned to its Standby Position, and the

device prepares to switch itself off. (Note that, in order to obtain its measurements, the

device – once every four minutes – momentarily disconnects the panel from the battery:

the 'clicking' sound you may hear emanating from the device's enclosure, is produced by

an electromagnetic relay, operated by the device's microprocessor, which controls the

connection between the solar panel and the battery it is charging).

The device is also designed to tolerate sudden reductions in light levels, such as may be

caused by a person walking past the device and temporarily shading it from the sun.

STANDBY POSITION

The Standby Position of the Head is an important operational feature which – when the

device is positioned as advised facing south (or north) – serves multiple purposes: 1) by

returning the panel to a south (or north) -facing orientation from its west-facing orienta-

tion at sunset, the device – which is activated by light falling on its panel – is better

situated for re-activation the following morning by the sun as it rises in the east (if the

device remained facing west when de-activated at sunset, if would be facing in a direc-

tion poorly-suited for activation at sunrise); 2) the device's automatic de-activation at

sunset is assisted by the panel rotating away from the setting sun, back to its Standby

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