MGL Avionics Stratomaster Ultra “L” Owner’s manual
Page 65
Should you require a suitable replacement probe, it can be obtained from MGL Avionics at
reasonable cost or you can make up your own probe. In this case please obtain a National
Semiconductor Temperature Sensor type LM335 in a TO92 package.
External, visual alarm indicator
The above drawing shows a suggested wiring layout for an external alarm indication. We suggest
using a 12V / 1W indicator lamp such as can be found in many automotive parts supply shops.
These indicators (called pilot lights) come in many colors, sizes and shapes. Choose a pilot lamp
that will ensure that you will see it flashing, even in bright sunlight. Install the lamp in a position on
your dash or aircraft that will ensure that you will see it. Remember many costly engine failures
can be prevented if you see problems early enough.
Please note: the drawing above leaves out the switch between the (+) terminal of the battery and
the Stratomaster Flight unit for simplicity.
The Stratomaster Ultra provides an uncommitted contact (i.e. not connected to anything) that
opens and closes once a second in the case of an active alarm. This can be used to switch a light
bulb (as shown above) or switch a small buzzer or siren.
The contact is rated for a maximum current of 0.5 amperes (500 mA) at 50 V maximum. Please
do not exceed this specification as this could harm the internal reed relay contact.
Alarms can be generated for over speed, under speed, engine temperature over limit, altitude
over limit and low fuel levels. Please view the Owners manual on how to setup the alarms.
Please note that the Stratomaster Ultra will close the alarm contact for a few seconds every time
the unit is switched on. This is intended to provide a means of checking that the alarm is
functional during pre-take-off checks.
12V Battery
12V indicator lamp,
maximum wattage
rating 24W
