Technical informations




     > Construction
     > Construction of copper cable
     > Laboratory



  1. The Ignition System
  2. What is the purpose of an ignition wire set?
  3. Sentech® ignition wires, an advanced technology
  4. Sentech® cable, an original patent
  5. Sentech®, cables adapted to each type of engine
  6. Comparison of different technologies existing on the market




  1. The Ignition System

    The purpose of the ignition system is twofold:

    The basic principle of the electrical spark ignition system has not changed for over 75 years. What has changed is the method used to create the spark. The automobile has evolved from a mechanical system (distributor) to a solid state electronic system. Both systems control a low voltage primary circuit through an ignition coil which will induce a high voltage in the secondary circuit. This is then directed to the right spark plug, at the right time.
    • to create a voltage high enough (20'000 V) to arc cross the gap of a spark plug, thus creating a spark strong enough to ignite the air/fuel mixture for combustion;
    • to control the timing so that the spark occurs at the right time and in the right cylinder.

  2. What is the purpose of an ignition wire set?

    Ignition wires channel high tension energy from the coil to the spark plugs in order to produce the spark necessary for ignition without disturbing the environment with high frequency electrical interference.

  3. Przewody zapłonowe SENTECH®, zaawansowana technologia

    Sentech® technology is the result of advanced laboratory research. Each detail represents an innovation. All stages of the manufacturing process: cable, terminals, boots are controlled and tested.


    The exacting requirements of international car manufacturers and zero defect performance over high mileage means selecting the finest materials:

    Metal terminals cannot be crimped directly onto the rubber sheath without the braiding as:

    The braiding forms a sort of net that "traps" the dielectric insulator and stops the diameter from getting smaller. In this way any increase in cable length is impossible and the lead keeps all its flexibility.

    Terminals: Boots:
    • The electrical insulation is achieved by a layer of plastic, thermoplastic elastomer or synthetic elastomer which, due to its characteristics ensures the low linear capacity of the cable which in turn minimises the voltage drop between the coil and the plugs.
    • The outer sheath ensures the mechanical and thermal protection of the cable against engine environment and ambient conditions (temperature, oils, fuel, salt water, humidity, cold...)
    • The braiding is made of polyester or glass fiber, which makes it resistant to mechanical stress. This ensures the correct crimping resistance of the terminals.
    • Metal terminals would tear the rubber sheath when pulled
    • The diameter of the outside sheath and the dielectric insulator would get thinner (like stretching elastic), which would make it easier for the terminal to get pulled off.
    • Their shapes are designed according to the application (plug nut, male, female, threaded connection), to their dimensions and adapted for automatic assembly and automatic fitting of clips during the terminal manufacturing process itself. They insure the mechanical and electrical link with the female terminals, the plug nuts, the threaded posts of the distributors, coil and plugs.
    • The crimping on the cable and the strip and fold or staple technologies developed by Sentech® provide the electrical link with the wound conductor of the cable and contributes to a good electrical conductivity of the ignition lead in whichever engine and ambient condition.
    • The main purpose of the boots is providing protection and dielectric insulation for the high voltage electrical connections.Therefore the materials are carefully selected and their shape and designs are adapted for each application to ensure a tight grip on the cable and on the connecting elements (spark plug porcelain and distributor or coil).

  4. Sentech® cable, an original patent

    Sentech® created the wire wound cable technology in 1957. A very small diameter resistive wire is wound around a ferro-magnetic core which absorbs electromagnetic interference and conducts the high voltage current without loss of energy. It protects the low-voltage network from interference due to the high-voltage ignition current.With Sentech® technology the highest degree of E.M.R. attenuation is achieved. Radiation is absorbed all along the cable, thus eliminating interference on radio, TV, mobile phone and on the electronic equipment in the car.

    Note: the level of reference represents a level of "electromagnetic noise" following an international standard.
    In frequency ranges used for television and radio waves, Sentech® is different to most of its competitors. Interference suppression is one of the strong points in Sentech® ignition wire technology

  5. Sentech®, cables adapted to each type of engine

    Sentech® cables are marked with indelible ink during manufacture. This marking gives the product a full identity and specifies the grade of the cable according to its working temperature
    Cable grade A B C D E F
    Maximal temperature (°C) 80 100 120 140 160 180
    Minimal temperature  (°C) -20 -30 -30 -30 -30 -30
    Thermal overload temperature (°C) 105 120 155 180 220 250

6.Comparison of different technologies existing on the market

There are three design technologies for cable capable of suppressing interference waves that spread in the circuit after combustion:
  • Copper Core and resistive terminal technology

    Copper cores are the oldest type of technology; they are mainly used by German car manufacturers and work on the following principle:

    A copper wire (whose resistance is virtually zero) is associated with a resistor placed as close to the spark plug as possible (in the terminal).

    Thanks to this resistor, a part of the wave is reflected in the opposite direction (like an echo) and then sent to the vehicle's ground. Another part is radiated into the surrounding environment and the rest is transmitted into the cable. So, because the wave that is transmitted is weaker, it causes less interference to environment.

    Even so, this resistive effect plays a negative role in sparking, as all the energy transmitted by the distributor does not get to the plugs.
  • Carbon core technology

    This technology is to be found mainly amongst English and American car manufacturers. It uses carbon whose resistance is spread throughout the length of the cable. The carbon core cable has a very short life and cannot guarantee that resistance values are the same for the different leads in the set: in fact, resistance can vary in ratio from 1 to 10. Due to its short life span, this type of ignition wire set needs to be changed frequently.

    These two solutions are relatively efficient for low frequencies (several MHz). However they are inadequate for high frequencies as their resistance is the same no matter the frequency.

    What must be remembered is that:
    High resistance = energy losses = extra pollution
  • Spiral core technology (Sentech® process)

    A stainless steel wire is wound in a spiral around a ferromagnetic core gives unique construction. When a current crosses the wire a magnetic field is created inside.

    Two effects combine to give excellent interference suppression:
    • The inductive effect Electromagnetic interference waves are guided by the ferrite cores and then absorbed.
    • Resistive effect The spirally wound wire acts as a resistance for up to 5600 Ohms/ m. Therefore, the resistive effect that is effective on low frequencies is improved by the inductive effect. This type of technology is ideal for high frequencies.


Spirally wound ferrite core technology combines the advantages of the two other types of technology.