Dynalco LST-108L Tachometer - Manual (Page 2)

Dynalco Controls, 3690 N.W. 53rd Street, Ft. Lauderdale, FL USA 33309
TEL: (954) 739-4300 FAX: (954) 484-3376
0396F
LST-108 and LST-108L are trademarks of Dynalco Controls
DYNALCO CONTROLS RESERVES THE RIGHT TO CHANGE THESE SPECIFICATIONS WITHOUT NOTICE.
1. Calculating Signal Frequency (in Hz)
Multiply RPM times the number of teeth (or discontinuities), then
divide by 60. For example, sensing a ring gear with 113 teeth rotating
at 1800 RPM gives a frequency of 3390 Hz.
(RPM) x (Teeth or Discontinuities)
60
(1800 RPM) x (113 Teeth)
60
Signal Frequency in Hz =
Signal Frequency in Hz = = 3390 Hz
2. Calculating Gate Time (In seconds)
Divide the number to be displayed on the LST-108 or LST-108L
by the corresponding signal frequency.
Gate Time = = 0.53 seconds
.
3. Gate Time Range Selection on 4-Position Switch
Select either position for each number pair on the switch:
Position 1: 0.14– 0.38 sec. Position 2: 0.38–0.76 sec.
Position 3: 0.76– 1.51 sec. Position 4: 1.51–3.02 sec.
4. Pulse Rate Multiplier: Required gate time can be divided by
ten if a jumper from 4 to 5 is used. The input pulse rate will
be multiplied by ten times. Required gate time can be
divided by one hundred if a jumper from 5 to 6 is used. The
input pulse rate will be multiplied by one hundred times.
1800 RPM
3390 Hz
Optional Calibration Method: On-engine
A. Select the appropriate gate time range on the 4-position switch.
B. Connect the magnetic pickup output to terminals A & B.
C. Adjust vernier potentiometer on LST-108 or LST-108L until its
display agrees with another precise digital tachometer.
OUTLINE AND CONNECTION DRAWING
© 1996