This page details the reverse battery damage that can occur to a VTX or NCC if the battery is connected the wrong way round. Be warned that reversing the battery is instant death to the Read More

NCC series controllers. Ramps – acceleration and deceleration. Details of the equivalent modification to the Pro-120 are on another page. Introduction The ramps on the NCC are adjustable from around 300mS to around 7 second, Read More

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

NCC series Mark 2 4 Quadrant 12v, 24v, 36v & 48v Vehicle controllers This page is for reference only. The NCC is no longer available. The latest equivalent is the DNO range. NCC Mark 2 Read More

  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

This description refers to the Issue 18 and later NCC Mk1 series controllers. Circuit Diagram The NCC Mk 2 and the VTX are similar: main additions on these are an adjustable Reverse Acceleration Threshold (a Read More

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

The NCC Mark 2 was issued in 2003 as an update to the earlier highly successful NCC controller. It is very similar – the main noticeable difference being that there is a reduced deadband at Read More

These Mark 1 controllers are now too old for factory service. Warning: this listing was originally generated for 4QD internal use only, so is not as fully detailed as it should be if it were Read More

This page identifies some of the key NCC components. It shows a Mk 1, issue 24 controller. Mk 2 is similar, but uses sub-miniature resistors. Mk 1 boards issue 18 and later are similar to Read More

Symptom If the main power line zener has been damaged, the voltage on the pot will be lower than 8.5v. However, this voltage being low can also indicated that the pot fault transistor has been Read More