Innovate Motorsports LM-1 RPM Converter (Aux. Input Cable 2) - Manual (Page 9)

7.1 Recording the state of a NOS solenoid
or
Figure 4. Solenoid Interface (High Side Switch, Low Side Switch)
In the left case the solenoid is grounded on one side, the other side is switched to 12V when the
solenoid is on. The LM-1 will record 3.3V when the solenoid is on, and record 0V when the
solenoid is off. In the second case the solenoid is connected to 12V on one side and the other
side will be grounded when the solenoid is on. The LM-1 will record 0V when the solenoid is on
and 3.3V when the solenoid is off. The same method can also be used to detect other signals like
clutch switch and so on.
7.2 Recording Battery voltage or a signal between 0 and 12V
This circuit creates a load of 330 kOhm on the signal. If your measured signal has a high output
impedance (> 33 kOhm), increase the resistor values in the circuit proportionally.
Figure 5. Battery Voltage or high signal amplitude interface
The measured signal is divided by 3. The maximum battery voltage that can be measured is 15V.
The recorded voltage will be 1/3 of the actual voltage. Either multiply the measured voltage in the
log by 3 or set up the appropriate input as custom as described in the LM-1 manual.
8.1 Revision History
Version 1.0- November 20, 2003- Initial Release
Version 1.1 – December 10, 2003
Version 1.2 – May 12, 2004 –Update LM Programmer screen shots and references