SYM VTS 200 Rectifier/Regulator

Ever since Nicholas Tesla discovered the Alternating Current (AC) it was a fierce battle between him and Edison who "discovered" Direct Current. On scooter both exist harmoniously complementing each other.


Scooter like any motor vehicle needs electrical power to make it work, at least to the ignition coil igniting the combustible mix or engine cranking during start.


Basic electrical power supplied by battery, however this accumulator need recharging and if its left running an engine without very soon everything will come to a stop. To do this charging there is a Generator on board that runs by the engine to produces electric current. Big problem these are Alternators which produces AC and they run at a wild frequency of the engines speed, further to the problem its varies in output current and voltage by this engine speed too.


Enter the world of Rectifier/Regulator, on most bike inclusive scooters this is the unit that will convert the AC to DC and at the same time regulate a steady voltage output of about 13.5 ~ 15.5 VDC which are use to charge the battery and powering the rest of the electrical components on the scooter.


Below is the SYM VTS 200 Rectifier/Regulator its on the right side of the body, this photo shows it with body panel removed.

Replacement of this Rectifier/Regulator don't need the body panel to be removed. An experience mechanic can easily get it from the right side of the bike and with some fiddling the unit can be remove. This unit get hot while in operation, that is why this is the best location for it.

Its held with two 10mm screws and you need a socket wrench for the job. Once dismounted, you will need to undo the weather shield to get to the two connectors.

Exposing the 2 connector with 3 wires each. The yellow wires are from the Alternator, Green to Earth, Red to Battery and Black to Indicator. However its best to get the exact diagram to be sure.

Above is a very simplified diagram and below for few type of SYM Motors.

Below with one of the connector exposed.

Close up of the regulator.

The part number on the back.

These Rectifier Regulator are tested with the engine running at 2000 RPM, it should produce about 15V and charging the battery at about 1.2A with High Beam "ON"


There are other type of regulators around, generally its either a Single Phase input or like this a 3 Phase input. All 3 phase input Regulator/Rectifier work the same and to the extend they can be made to work on any bike, but to do this you may need to know Tesla.