Davtron M850 User manual

FEATURES
ßTwo button control system is natural and error
free. Setting operations are identical for both
alarm and time setting. Patent Pending.
ßBright sunlight readable incandescent displays.
ßIlluminated buttons and annunciators for
night viewing.
ßFlight Time recorded in hours and minutes or in
hours, tenths, and hundreds.
ßSerial time data output for remote use.
ßFlight time alarm with external output.
ßElapsed time count down timer with alarm.
ßA 4 MegaHertz crystal precision time
reference.
NOTE: Keep Alive (Pin 9) is only required if alkaline N size battery is removed. Flight Time starts with either
Pin 3 or Pin 4 – use only one pin.
SPECIFICATIONS
ßGreenwich Mean Time: 24 hour format.
ßLocal Time: 12 hour format,
24 hour option.
ßFlight Time: Records in 99:59 standard,
99:99 hour option.
ßFlight Time Alarm: Full set range flight time.
ßElapsed Time Count Up: Starts in minutes,
seconds, then hours, minutes up to 99:59 hrs.
ßElapsed Time Count Down: Settable from
one second to 59 minutes, 59 seconds.
ßElapsed Time Alarm: Activates at zero
when counting down.
ßIncandescent Displays: readable in sunlight.
ßAutomatic Dimming
ßBattery Type: N size alkaline.
ßPolarizing Filter
ßKeep Alive Current: .00004 Amps.
ßInput Current: .2 Amps.
ßInput Voltage: 28V
(backlight available 5V, 14V, or 28V (must specify)
ßCrystal Reference: -40C to + 60C .001%.
ßWeight: 5 ounces.
ßWarranty: 1 year.
ELECTRICAL
MECHANICAL
5
4
3
2
1
9
8
7
6
- +
+
Alarm Out
Keep Alive .00004A
Ground to start Flight Time
Dimming 28V at 50MA, 5V or 14V available
4V to 28V Starts Flight Time
Serial Data Output /optional
14 or 28 Volts, .2A
Serial Clock Output /optional
GND
Audio Alarm
.25A
Battery
2.46 MAX
1.46
.750
.125
C
L
2.250
+.005-015
TYPE N
BAT TERY
DATA PL ATE / SE RIA L NU MBE R MO UNT ED O N BOT TOM
.050
CG
CHRONOMETER
SELECT CONTROL
CTLSEL
GMT LT FT LT
23:59
2.375
3.00
4-40 CS
82 ° TYP
4 PL.
TYP 45 °
4 PL.
427 HILLCREST WAY
REDWOOD CITY (Emerald Hills). CA 94062
[phone]
www.davtron.com
DIGITAL CLOCK
M850
Incandescent Display
GREENWICH MEAN TIME
LOCAL TIME
FLIGHT TIME - Flight Time Alarm
ELAPSED TIME - Count Up, Count Down, Alarm

M850 LSI Aircraft Time Management System
CLOCK OPERTION
Normal Operation
The SEL button selects what is to be displayed on the
four digit window and the CTL button controls what is
being displayed. Pressing select sequentially selects
GMT, Local Time, Elapsed Time and back to GMT. The
CTL button starts and resets Elapsed Time when
momentarily pushed. Normal operation of the 850 can-
not accidentally reset time.
Setting GMT
Select GMT for display in the four digit window with the
SEL button. Simultaneously press both the select and
control buttons to enter the set mode.The tens of hours
digit will start flashing. The control button has full con-
trol of the flashing digit and each button push incre-
ments the digit. Once the tens of hour is set, the select
button selects the next digit to be set. After the last digit
has been selected and set with the control button, a
final push of the select button exits the mode.The light-
ed annunciator will resume its normal flashing, indict-
ing the GMT clock is running.
Setting LT
Select Local Time, LT, using the SEL button.
Simultaneously push the SEL and CTL buttons to enter
set mode. The tens of hours digit will start flashing. The
set operation is the same as for GMT, except that min-
utes are already synchronized with the GMT clock and
cannot be set in Local Time.
Control/Select Disable
When there is no aircraft power applied in the clock
CTL and SEL buttons are disabled.
Setting Flight Time Alarm
When Flight Time, FT, is displayed enter the set mode
by pressing both buttons simultaneously. The alarm
time is entered identically to GMT setting. When the
Flight Time equals the alarm the display will flash
and the alarm output activated. If FT was not being dis-
played at the time the alarm becomes active, the clock
automatically selects FT for display. Pressing either the
SEL or CTL button turns off the alarm and zeroes the
alarm time. Flight Time is unchanged and continues
counting.
Flight Time Reset
FT must be displayed when resetting. Hold CTL down
for 3 seconds, or until 99:59 Or 99:99 appears on the
display.The digits that appear depends on how the clock
is programmed. In hour and minutes, or in hours,
tenths and hundredths. Flight Time will be zeroed upon
release of the CTL button.
Elapsed Time Count Up
Select ET for display. Pressing the CTL button will start
ET counting. Elapsed Time counts up to 59 minutes, 59
seconds, and then switches to hours and minutes. It
continues counting up to 99 hours and 59 minutes.
Pressing the CTL button again resets ET to zero.
Elapsed Time Count Down
Select ET for display and enter set mode by pressing both
buttons. The countdown timer can now be set. Entering
the time is identical to GMT time setting. When the time
is entered and the last digit is no longer flashing the clock
isreadytostartthecountdown. Momentarilypressingthe
CTL button starts the countdown. When count reach-
es zero he displays flash and the external alarm is acti-
vated. Pressing either SEL or CTL will deactivate the
alarm. ET continues counting up.
Test Mode
Hold the SEL button down for three seconds and the
display will indicate 88:88 and activate all four annun-
ciators.
FIELD OPTION CHANGES
When changes are made the connector of the clock
must be grounded to the soldering iron or warranty
may be void.
Serial Time Data: To change from GMT to LT, remove
case and jumper LT.
Local Time: To change from 12 hour to 24 hour format,
remove case and jumper 24.
Flight Time: To change from recording in hours, min-
utes to recording in hours, tenths and hundredths,
remove case and jumper 99.
Battery Removal: The battery and battery holder may
be remover permanently if the aircraft battery is con-
nected to the Keep Alive input (Pin 9). No changes in
the clock are required.
Voltage Input is 28 Volts standard. To change to 14
volts, the two large lamps that illuminate the buttons and
annunciators should be changed from OL-6838 (28V)
to OL-1089 (14V) bulbs. If the Keep Alive (Pin 9) is
used, R-1 must also change from 560K to 220K. Call
factory for directions. No change is required for the
input power (Pin 2).
Remote Time Display: Additional time displays can be
driven by the M850 clock. Only two wires carry the time
information to the remote display. The remote displays
have independent automatic dimming. Either GMT or
LT may be displayed. Remote display units are available
from Davtron, Inc.
STANDARD AND
OPTIONAL FEATURES
Local Time 12 hour format, 24 hour option.
Flight Time in standard format of hours, minutes,
(99:59) or optional format of hours, tenths and hun-
dredths up to 99:99.
Flight Time Settable Alarm when FT
reaches programmed alarm time the display flashes
and the external alarm output is activated.
Elapsed Time Count Up counts in minutes
and seconds up to 59 minutes and 59 seconds and
then changes to hours and minutes up tp 99 hours and
59 minutes.
Elapsed Time Count Down may be set to
count down anywhere from one second to 59 minutes
and 59 seconds.
Elapsed Time Alarm when the count down
time entered reaches zero the display flashes and the
external alarm output is activated.
Serial Time output standard is GMT, Local Time
options.
Voltage Input is 28 Volts standard, 14 Volt
option.
Battery is a N size alkaline cell. The rec-
ommended change interval is one year. The clock
is available without battery from the factory. Keep
Alive (Pin 9) must then be connected to aircraft
battery.
Note Battery can be easily removed and replaced
without removing clock from aircraft. Battery holder is
polarity marked with red end positive (+).
Greenwich Mean Time Local Time
Flight Time Elapsed Time