DC Analogue Stay-Alive Capacitor for Model Railway Locomotives

Improve the running continuity of compatible DC analogue model railway locomotives with a Hobby Trax stay-alive capacitor. The unit stores energy and briefly supports the locomotive motor when dirty track, points or momentary contact loss interrupts track power.

Choose from pre-wired versions for older locomotives or plug-in versions designed for a compatible 8-pin socket. Several capacitor sizes are available so you can select the largest option that will fit inside the locomotive.

Connection options

• Pre-wired version: Supplied with flying leads for soldering directly across a compatible motor. Recommended for many older pre-DCC Hornby and Lima locomotives, including accessible ringfield and pancake motors.
• 8-pin plug version: Designed to plug into a compatible 8-pin socket normally used for a DCC decoder.

Capacitor sizes

• Small: Approximately 10mm wide × 16mm long
• Large: Approximately 13mm wide × 20mm long
• SuperCap: Approximately 18mm wide × 47mm long

For the strongest stay-alive effect, fit the largest compatible capacitor that available space allows. Newer, lower-current motors will generally benefit more than older, high-current designs.

Installation

For the wired version, solder the leads directly across the compatible locomotive motor. Check available internal space, motor type and wiring before installation. If you are unsure, seek assistance from an experienced model railway technician.

Performance observed during testing

During Hobby Trax testing with an older Hornby ringfield motor, the large capacitor allowed the motor to travel approximately 46% farther after power was removed. The SuperCap produced an improvement of more than 200% in the same type of test. Actual performance will vary with the locomotive, motor, speed, track condition, load and capacitor size.

Important compatibility and safety information

• Not compatible with the Hornby R7229 analogue controller.
• Older high-current motors, including designs such as the Tri-ang X04, may receive only a limited benefit.
• Use only a capacitor selected and configured for this application. Do not solder an ordinary capacitor directly across a locomotive motor, as this may cause damage.
• Confirm polarity, wiring and controller compatibility before installation.

A practical stay-alive solution for improving low-speed reliability and reducing stalls on compatible DC analogue model railway locomotives.