HALL EFFECT SWITCH

VCC OUTPUT HALL GENERATOR FLUX CONDUCTORS HALL (SOFT IRON) VOLTAGE

FIG. 1: HALL EFFECT PRINCIPLE MAGNET

CASE (PLASTIC) GROUND Fig. 2 HALL EFFECT SWITCH Fig. 3 by JOHN CLARKE Bre k I ignition

and replace it with the rotating vane assembly. It is located and held in exactly your the same manner as the original rotor for button. The Hall Effect sensor, however, Designed specifically for Australian -made , requires several hours of work to install. This mainly involves the fashioning of a this breakerless ignition system employs a suitable mounting plate for the vane commercial Hall Effect- switch, which is located on the vacuum trigger and rotating vane advance plate of the distributor. It must assembly. It can be used with both transistor be located so that the rotating vane assembly passes through the slot of the switched and capacitor discharge systems. sensor without scraping (see installation). When complete, you will have the many advantages available from solid In December last year we provided Siemens device comprises both a Hall state triggering. Once set the ignition details of a Hall Effect trigger sensor and integral magnet in a slotted timing will always be correct. It will not modification for the EA Transistor plastic housing which mounts in place of vary due to the gradual wearing Assisted Ignition and CDI units. This the contact points. down of the contact breaker rubbing utilised a Hall Effect distributor kit made The Bosch rotating vane assembly block and there will be no "timing scatter" by EDA Sparkrite of the UK and replaces the original rotor button in the due to distributor cam wobble or wear in the marketed by Jaycar. Although the distributor. It contains a rotor button bearings. The engine should modification proved very popular, it had and soft iron vanes. The vanes are also run noticeably smoother, especially the drawback that it was not suitable for spaced equally and pass between the at idle speeds. many Australian -made four, six and magnet and Hall effect sensor. This, in 8 -cylinder vehicles, including the much turn, provides appropriate pulses to the beloved Kingswood. following electronic ignition circuitry. The Hall Effect This dreadful omission has now been The Siemens vane switch is stocked by What is the Hall Effect? rectified with our new breakerless Jaycar while the Bosch rotating vane The Hall Effect sensor principle is ignition system. It is suitable for most assembly is available from Bosch shown in Fig. 1. It consists of a thin strip Holden, Ford, Chrysler and some automotive retail outlets such as Bennet of semiconductor material through Japanese makes which use Bosch, Delco, and Wood and . The latter is which a current is passed. When a Lucas, Disilea, Nippon Denso and actually used in the Bosch Electonic magnet is brought near, such that its various other distributors. Included are Ignition system and is sold separately for field is directed at right angles to the face typical Australian six and 8 -cylinder about $30. Before embarking on this of the semiconductor, a small voltage cars, as well as most of the popular project, readers are advised to contact appears at the contacts placed across the 4 -cylinder models. their local Bosch outlet and verify that a narrow dimensions of the strip. As the The basic mechanical concept is rotating vane assembly can be supplied magnet is removed the voltage drops to simple. It is based on a Hall Effect vane to suit their particular type of vehicle. zero. switch manufactured by Siemens of Installation of the rotating vane A practical Hall Effect device is West Germany, and a rotating vane assembly is very simple - just remove depicted in Fig. 2. This comprises a assembly from Bosch . The your rotor button from the distributor voltage regulator, a Hall cell, an 52 ELECTRONICS Australia, September, 1984