Model Locos

Airwire Interface

We’ve been asked by a number of customers if our controllers can be made to work with the Airwire system. This little circuit ought to do the trick…. With pins 2 and 3 of Lk1 Read More

High Current DCC Controller

We’ve been asked by a number of customers if it is possible to use the DCC system to control 4QD units. This page shows the outline of a way this can be done to create Read More

Double Heading Wiring Diagram [DNO]

This diagram shows how to connect two DNOs in different model locomotives together using the expansion port.     You can download a PDF version here. For the slave cable we recommend using a bulgin Read More

Mtroniks and regen braking

One of our customers has brought to our attention an issue that can arise when using an Mtronics sound card with a controller that has regenerative braking [all 4QD controllers]. The model in this case Read More

Towing

Towing an electric vehicle with a permanent magnet motor can cause major problems. If any E.V. is to be towed, you must disconnect the motors or else jack the machine so that the drive wheels Read More

Phoenix Loco Wiring

4QD supplied the complete wiring for Phoenix locos and the wiring of the loco is shown here for the convenience of Phoenix customers. This equipment was supplied only through Phoenix and enquiries about the locos Read More

Loco Wiring: Hand Control & Horn Relay Board

4QD’s Reversing Bell throttle hand control and associated Horn Relay Board are designed to simplify miniature Loco wiring whilst maximising features available. The Reversing Bell throttle gives a dead man speed control and may be Read More

Double Heading Problems

Systems using the expansion connector to double head with a pair of controllers (Pro-150 or Pro-120 or DNO or VTX) almost always simply work when wired correctly. But there are occasional problems with installations: Wrong Read More

Double Heading Switch

We were asked for a system such that either loco could be at front and could be facing either way. This seems to make selection of reverse very complicated, but it is in fact quite Read More