Waveforms and Fault Finding

  Although this page refers specifically to NCC series controllers, the principles apply to several other controllers of our manufacture as most employ very similar circuitry. The principal exception is the 4QD series. Warning If Read More

Internal Power Supply and Protection Circuitry

The Pro-120 and Scoota series controllers have some sophisticated internal power supply circuitry which includes reverse polarity protection, pot fault detection and high pedal lockout. This is a description of the features and of some Read More

Fitting Expansion Connector

Pro-120, VTX and NCC series controllers. Retro-fitting expansion connector Contents, this page Introduction Mark 1 / Mark 2 mixes VTX Pro-120 NCC Double Heading Tacho feedback board Solder Side All Controllers Additional controllers Older issues Read More

Positional Servo Control [DNO / VTX]

Notes on how to create a positional servo control. There are two types of servo system: speed and position. These are explained in our Answers to FAQs on Battery Motors & Controllers. There is also Read More

Wiring for Push Button Use

This diagram shows how to connect a Pro or DNO (or earlier NTX and NCC) series controller for push button use, or with a centre-off switch. Note that the diode shown between the buttons must Read More

VTX Modification History

VTX modification history: The VTX has changed relatively little in its life since first introduced on 2004. The best indicator of a controller’s age is the date code hand-written on the board, of the form Read More

VTX Speed Controller

The VTX was one of our most popular 24v motor controllers which was also made in 12v, 36v, and 48v variants. It has now evolved into the DNO range which is electrically interchangeable with the Read More

VTX and NCC Operating Voltages

  These notes refer to the last issue of VTX controllers. So if you controller is older, the notes may be sequentially less ‘correct’. All controllers made by 4QD are generally wide voltage operating range: limits Read More

VTX / NCC Fault Finding

Introduction Common faults on the NCC & VTX  series are – not common.  But there are a few faults which occur, mainly because the ‘bare board’ style of the controller makes it vulnerable to damage. You will Read More