Lx1 inductive sensor for diagnosing ignition system
13$
The sensor is designed for diagnosing distributor, DIS and COP systems. Two or more ignition coils are diagnosed one by one. The sensor also receives a signal of synchronization from the first cylinder. It’s used for measuring secondary voltage parameters, accessing ignition spark capability and identifying problems related to high-voltage wires, plugs, caps and coils.

Key Features

 
Manufacturer

ROTKEE (Ukraine)

Number of simultaneously diagnosed coils

1

Output connector

BNC

Supply voltage

not provided

Output Signal Type

analog

Operating temperature range

-20 to 80℃

Output Signal

Weight

Recommended Sampling Rate

not less than 250 kHz

Signal Cable Length

2.5 m

Housing Material

polyurethane

Contents of delivery

  • Lx1 sensor – 1 pcs
  • Double-sided foam tape – 1 pcs
inductive sensor Lx1 contents delivery

Video lessons

Diagnosing an ignition system with the help of a Lx4 sensor and automotive oscilloscope MT Pro, connecting the sensor to the engine, oscilloscope tuning, oscillogram recording while idle running and increased load. I’ll demonstrate all of this with an example of Seat Ibiza.

Sensor Design

A soft microphone cable with thick braided screen is used as a cord. BNC is used as a sensor-oscillograph connector.

Sensor case is made of polyurethane, which makes a sensitive sensor element damage-proof.

Under development high emphasis has been placed on cable and sensor joint as this junction is damage-prone. These joint includes a circuit board with the sensor’s electronic components. The board not only supports the loads, but also fixes the cable. Such solid joints prevent cable breakdown and increase its durability.

The sensor was developed as compatible with MT Pro automotive oscilloscope as well as any other oscilloscope, analog channel or synchronizing channel (if used as a synchronizing sensor).

Diagnostic Technique

The detecting element of an Lx1 sensor is an inductance coil. In order to detect a secondary voltage signal, the sensor’s detecting heads are to be fixed on the surface of the ignition coil, within its electromagnetic field. Generally, the upper part of the ignition coil is a flat area for the detecting head to be placed on. Double-sided foam sticky tape will do for the fixing on the coil case. Before assembling the surface of the coil and sensor is to be cleaned and dusted.

Sensor Operation Principle

The ignition coil of the internal-combustion engine operates on the principle of a step-up transformer and has two windings and a shared core. Therefore, when current strength in the primary winding changes, it triggers emf, which results in current strength change in the secondary winding, and vice versa. If an extra inductance coil is placed in the ignition coil’s electromagnetic field, it’ll cause emf in proportion to the changes in the coil’s magnetic field. This is how a secondary voltage oscillogram is obtained.

The secondary voltage signal’s shape depends on the sensor’s location in relation to the coil’s electromagnetic field. That’s why when placing a detecting head it’s advisable to keep in mind the following. The symmetry axis of the sensor’s detecting coil is to be placed along the axis of the ignition coil’s core. The distance between the coil and the head is to be as minimum as possible. If you can’t define the ignition coil’s type by eye, you can then change the sensor’s location in relation to the ignition coil until the oscillograph receives a signal with the biggest amplitude.

The precise Lx1 synchronizing sensor’s location isn’t that crucial, as its function is restricted to detecting breakdown impulse.