Lx6 inductive sensor for diagnosing ignition system
39$
The sensor is designed for diagnosing distributor, DIS and COP systems (up to 6 ignition coils are diagnosed simultaneously). 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

6

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

  • Lx6 sensor – 1 pc
  • Double-sided foam tape – 1 pc
inductive sensor Lx6 contents delivery

Video lessons

Diagnosing an ignition system with the help of a Lx4 sensor and automotive oscilloscope, 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

Six detecting heads mean making measurements using 6 ignition coils simultaneously, which allows analyzing signals from all the engine cylinders. As ignition pulses never occur instantly, signals from all detecting heads can be summed to get one signal with a series of sequential pulses identifying the ignition system as a whole.

Signal cables have such a length so as to be compatible with in-line, opposed and V-engines.

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 sensor development high emphasis has been placed on a signal cables joint as this junction is damage-prone. Each of these joints 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.

Diagnostic Technique

The detecting element of an Lx6 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.

In order to get a synchronizing signal, you also need to use an Lx1 sensor, which is placed on the ignition coil of the first cylinder, near the Lx6 detecting head.

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.