ALT-1 Operating Manual
Page 10
9 ALT-1 Specifications
Operating Temperature Range
-10ºC to 50ºC (14ºF to 122ºF)
Storage Temperature Range
-20ºC to 80ºC (-4ºF to 176ºF)
Humidity
<85% non-condensing
Power Supply
8 to 30Vdc SMPS (switch mode power supply) with built in 33V over
voltage and reverse voltage protection
Current Consumption
Approx. 45mA @ 13.8V (backlight on) 15mA @13.8V (backlight off)
Display
114x64 graphic LCD display. Contrast and backlight is user configurable,
green/yellow backlight
ADC
12bit over sampled successive approximation
Dimensions
see Infinity series dimensional drawing
Enclosure
2 1/4” ABS, black in color, front or rear mounting
Weight
Approx. 120 grams
Alarm contact current rating
Open collector transistor switch to ground. Maximum rating 0.5A DC
Non-volatile memory storage
100000 write cycles
Altimeter range
-700ft to 30 000ft (-213m to 9144m)
Altimeter resolution
1ft/1m
Altitude measurement accuracy
+/- 1mB, +/- 30ft at sea level
Digital VSI range
+/-20ft/m to +/-10 000ft/m
Digital VSI resolution
10ft
Analog VSI range
+/-2000 ft/m, logarithmic scale
VSI measurement accuracy
+/- 2%, relative to calibration
Airtalk protocol
19200 baud, 8 data bits, no parity, 1 stop bit (TTL voltage levels)
10 Installation
Connect the static port to a suitable static air pressure line. If you have a slow aircraft or an aircraft were the internal cabin
pressure does not change during flight and is equivalent to the outside air pressure you may find that it is not required to
connect a static port.
For installations in typical ultralight aircraft pods, be aware of possible pressure changes inside the pod during flight
caused by ram air or suction effects. This may lead to a false indication of altitude. Often these effects are dependent on
the current angle of attack of the airflow around your pod. You will need to install a suitable static port in these cases.
The use of an external 1A fuse is recommended. Connect the supply terminals to your aircrafts power supply. The ALT-1
can be used on both 12V and 24V without the use of any pre-regulators. Ensure that the supply voltage will not drop
below 8V during operation as this may result in incorrect readings.
10.1 ALT-1 DB9 Cable connections
DB 9 Pin
Color
Function
1
Black
Ground
2
Orange
OAT Sensor
4
NC
Airtalk communication (Not connected)
Used for firmware upgrading and
interfacing to the CNV-AT (Airtalk to
parallel Gillham code output encoder)
6
Red
8-30Vdc power
9
White
Alarm Output
