ISSPRO R8540 - Manual

ISSPRO, INC. 2515 N.E. Riverside Way, Portland OR 97211
Telephone: (503) 288-4488  Toll Free: (800) 888-8065
FAX: (503) 249-2999
Form IS121 (Rev B 5/10/02) Page 1 of 4
ISSPRO 5" Programmable Tachometer
Microprocessor Aircore Version
General Information:
Operating Voltage: 11-16VDC (24 VDC versions available)
Input Signal: Gear tooth sensor, AC generator, alternator tap
Programmable Range: 1-255 pulses per engine revolution (gear teeth, magnets, etc.)
Transient Protection: +100 V, -400 V
Reverse Voltage Protected
Hourmeter (optional) operates only when engine runs
Calibration:
Remove the calibration switch cover. Each of the first eight switches has a
different value as shown in the table on the right. Add the switch values to
equal the number of pulses per engine revolution. These switches will be
set “on” (up.) All others will be off.
Important: Switches 9 and 10 are always off.
Note: Power must be cycled when changing switch settings. If power is
left “On”, changing the switch will have no effect on calibration until power
is interrupted.
Example: Find switch numbers by subtracting the switch value from the remaining number. Always use the
largest value that can be subtracted from the remainder of
each successive step. For gear with 103 teeth:
Sw Value New Remainder Sw.#
Start 103-64 = 39 #7
Remainder 39-32 = 7 #6
Remainder 7-4 = 3 #3
Remainder 3-2 = 1 #2
Remainder 1-1 = 0 #1
Or use the calibration chart provide on pages 3 and 4.
Signal Generator (Sender unit): Generator is installed
on tachometer cable drive of engine:
#Pulses/Rev = (# sender pulses/turn) X (ratio of takeoff rpm to engine rpm)
If the number of pulses per revolution (from equation) is not a whole number the tach will not be accurate. In this
case, select a generator so that this number is non-fractional.
Example: # sender pulses per turn = 15, takeoff ratio = 0.5:1 (i.e. cam drive);
# Pulses / Rev = 15 X 0.5 = 7.5. This will result in an error in the tachometer reading. Select a sender with an
even number of pulses per turn (e.g. ISSPRO R8970). The # pulses per revolution will then be a whole number, in
this case 15.
Switch # Value
1 1
2 2
3 4
4 8
5 16
6 32
7 64
8 128
9 Off
10 Off
1 2 3 4 5 6 7 8 910
Back of Can
Dip Switch
Access Hole
Connector Wires
Grommet
On On