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Bob's Meccano Articles


Delay Reverse Control Unit

This electronic unit uses two push "ON" switches to stop an electric motor for about 5 seconds before setting the motor in the other direction.

The switch isolates both the electronic unit battery (nominally 6 volt) and the battery for the motor (any voltage from 1.5 volts to 24 volts depending upon the motor voltage) from the electronics unit when the toggle is in the position as shown in this photograph on the right.

All connections to the electronics unit are made with screw terminals, one wire per terminal to ease the wiring of the unit. A PDF of the instructions and wiring diagram for the unit is available here in a new window.

Whilst connecting the motor battery wrongly will not harm the unit; connecting up the electronics 6 volt supply battery wrongly would damage the unit. This is why the unit has a series connected diode to prevent this damage, if the battery is connected wrongly, the unit will not work but, will NOT be damaged.


The electronic control unit (shown on the right) mounted in my model of the locomotive "Sans Pareil"made by Timothy Hackworth of Shildon, County Durham, for the Rainhill Trials.

You can see the switch and the terminal connections quite clearly underneath the water barrel on the tender.

NOTE, the batteries for the electronic unit and the motor have been delibertly put overboard to allow the electronic unit to be seen.

Anyone wishing to buy one of these control units, cost 8.99, should contact Bob by email.

A video of my model of Sans Pareil running on a 3.5 inch guage track, being controlled by the electronic unit can be seen by clicking on the picture below.

Download the instructions and wiring diagram for this unit.