SkyAssistant variometer

Published on Sunday, 28 November 2010 12:41 | Written by Pitlab

The SkyAssistant variometer is a small on-board instrument which indicates the RC sailplane model's vertical speed by an audible signal. Lift is indicated by a pulsed tone with rate and frequency of the pulses depending on the climb rate. Sink is indicated by a low, continuous tone depending on the sink rate. Audible signal and voice messages about model state are transmitted by built-in radio transmitter and can be received on standard LPD or PMR receiver (European version), FRS (American version) or UHF CB (Australian version). Voice messages in all available languages can be listened on Language versions page.

Additional features of the SkyAssistant includes:

voice announcement of glider altitude in [m] or [ft] at reach definable altitude step (default every 50m),
voice announcement of on-board battery voltage, a message at each voltage drop of 0.1V and a voice alarm if it drops below a definable value,
voice announcement of temperature (battery, engine or air) in [°C] or [°F] with temperature data logging,
measurement of value and stability servo PPM signal and definable sound signal if interference is detected (works with PPM/PCM systems),
measurement of atmospheric pressure in [Pa] or [inHg],
triggering voice messages of measured values (altitude, voltage and temperature) by 3-way switch on RC transmitter,
few modes of work with vario tone on/off, automatic messages on/off, periodic messages on/off activated by 3-way switch,
user definable alarms: low voltage, high temperature, high altitude, PPM error,
recording of all measured values into Flash memory (logging time >10h in typical conditions: 5 parameters every 200ms),
easy firmware updating and automated actualization service,
all logged data of RC glider flight can be downloaded and graphed for off-line analysis.

Details about functional blocks you can find in the English version of documentation.

Actual variometer pictures:

Video from flights on International Żar Mountain Picnic:

SkyAssistant jest available in 2 versions with other type of pressure sensor:

Standard version - equipped with sensor without nozzle device height: 11 mm sensor hidden, preserved from sunlight by factory no availability to connect TEK probe	Nozzle version - equipped with sensor with nozzle device height: 13 mm sensor protruding, not preserved from sunlight available to connect TEK probe

Mounting variometer in RC sailplane

RC sailplane variometer should be mounted in vertical position with pressure sensor pointing up. In this position vertical acceleration forces acting on the sensor's membrane cumulative increase variometer sensitivity. Mounting with pressure sensor pointing on one side is not recommended, because centrifugal force increase variometer readings circling in one side and decrease when circling in other side. Variometer should also be exposed on direct sunlight.

Sailplane crashes sometimes happens even to experienced gliders. Try to predict what happens with variometer when you crash. Do not mount it in front of heavy components like batteries. Until will be hit with something heavy, the SkyAssistant board can survive most crashes.

Recommended receivers

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