Artisan. . there are two basic types of ignition "pickups" . One uses a magnet to trigger a transistor-like device (on or off), which is Hall Effect, the other uses a coil/inductive pickup connected to a transistor in an amplifier, and the voltage spike generated as the magnet swings by triggers the circuit. There are a number of different designs of each type.

Of interest is that both 3W and DA use a 2-wire "inductive" style pickup (although there are 3 wires at the plug) that not only senses crank position, but also helps to advance the ignitions timing automatically depending on how fast the magnet passes the coil. Inside "the box" DA, 3W, CH, and others use basically the same style of ignition "amplifier", with toroidal coil, capacitors and resistors, a smattering of diodes and semi-conductor devices (transistors or their like) to fire the coils.

Ch, Pro-spark, and others, use the external Synchro-spark module to control timing. There is no such circuitry evident on the DA/3W style ignitions, meaning that "advance" is almost entirely a function of engine speed and how quickly the magnet brings the pickup coils voltage level high enough to trigger the ignition to fire. It's a very simple design, and virtually bulletproof.