RPM-Pick-Up-Adapter

This adapter is for "traditional" ignition systems where spark plug is connected with spark plug (high voltage) wire to coil, distributor or magneto.

"Pick-Up"-part of the adapter cable:
Wrap the pick-up-part of the cable few times around the spark plug cable (min. 4 turns).
User must test the best placement for the antenna and number of pick-up wire turns, higher number of turns gives usually better signal.

Coaxial part of the adapter cable:
Try to keep the cable and adapter away from electrical noise sources (other ignition cables, coils, alternator, relays etc.) and hot parts of the engine. Use heat protection tubing if necessary. Minimum bend radius is 50 mm for the coaxial cable part of the cable.

Max. operational temperature +85C for the cable, +60C for other parts of the adapter.

Connections

Red wire/ Adapter Power input:
Use +5V output from RaceDAC.
Absolute max. voltage +6V.
Current consumption less than 5mA.

Black wire/ Adapter GND:
Use GND connector from the racedac.

White wire/ Adapter signal output:
Connect to the RaceDAC digital input (pulse amplitude 5V).

Configuration

If the ignition system gives you two sparks per one revolution ("wasted spark system"), configure RaceDAC digital input value to be divided by 2 (user divisor value = 2).

Input range is from 0 to more than 30 000 pulses per minute (30 000 rpm, or 15 000 rpm in wasted spark system).
Actual range may be a bit lower if there is too much noise in the pick-up signal, or if the pick-up signal level is low.

If you have problems getting the signal, and the the spark plug cable has a radio interference shield, it must be partially removed (peel the outer part of the spark plug cable) to get the signal.

Example configuration:

rpmadapterwirediagram