(1947-87) Speed / Tach Signal Interface Module

(Converts VSS/ECM speed signals to either 8k or 16k PPM) The SN74Z has the following features when used as a Speedometer interface. Input Source Options Three wire pulse signal generator input source Built-in Vehicle Speed Sensor (VSS) input source Most Tremec transmissions Later model 700R4’s Typically a sine wave signal Two wire pulse signal generator input source Classic Instruments SN96 or SN95 Typically a sine wave signal One wire ECM signals input source Typically a 5 volt square wave Output The output can be selectable between either 8000 pulse per mile or 16000 pulse per mile Outputs a 12V square wave, 50% duty cycle 8000 pulse per mile cruise control output Additional Benefits Three different calibration options Instant: drive 30 MPH and press the calibration button Real-Time: press and the hold the calibration button to match the speedometer reading to the actual vehicle speed Marked Mile: Drive a measured mile to calibrate the speedometer Input signal can range from 2000-200,000 pulses per mile State of the art signal averaging software that ensures smooth pointer operation, even in fluctuating signal conditions. Noise-reducing, filtered power output for powered speedometer signal generators The SN74Z has the following features when used as a Tachometer interface. Input Source Options High Voltage Coil signal input source .5-6 pulses per revolution (1-12 cylinder engine) Typically the negative side of an ignition coil 5-12V Square Wave signal input source .5-6 pulses per revolution (1-12 cylinder engine) 20%-50% duty cycle Typically from an electronic ignition box or computer Inductive Gear tooth sensor input source Typically used in diesel applications where there is not an ignition system The sensor can be mounted to the engine near the flywheel to sense the gear teeth as they rotate by Can be used with 32-510 tooth flywheels, 32-510 pulses per revolution Output Signal output 12V square wave, 50% duty cycle 2, 3, or 4 pulses per revolution (4, 6, or 8 cylinder) 3 preset flywheel tooth settings