The Electronic E-Unit is designed to replace the mechanical E-Unit in AC-powered model railroad engines. It sequences through the four states like the mechanical unit, and will resume at the next state when power is restored, regardless of how long power has been off. It uses 10 amp mechanical relays rather than semiconductors to control motor current, so there is no dissipation issue running higher power 2-motor engines. A customer provided lock-out switch to the chassis will retain the prior state – forward, neutral, or reverse – just like the mechanical E-Unit. DC motors can also be controlled, but an external full-wave bridge rectifier must be added to rectify the track AC waveform.
As received, the EEU will function exactly like a traditional mechanical E-Unit, but firmware versions 2.1 or higher can be reconfigured to operate in an enhanced power-up default state mode. In the default state mode, when power is shut down longer than two seconds the engine will resume either in forward or in the state it had been when power was shut down. The direction lock input chooses which default state mode is selected. A firmware update is available to add that feature to the original version EEU.
The Electronic E-Unit may be mounted with double-backed foam tape or a mounting flange to the chassis. It must be isolated from the chassis when controlling a DC motor. When mounted to the chassis by a metal flange, the removable FRAME GND jumper can be removed to isolate the EEU from the chassis.
A double-sided adhesive mounting pad is provided along with the mounting flange. Choose whichever mounting method is appropriate for your engine. When using the pad it is essential that no portion of the printed circuit board contacts the chassis. The mounting flange may be attached at either screw location on either side of the EEU. It may be easiest to first mount the flange to the chassis using the screw that held the original E-Unit. Then attach the EEU to the flange with the 4-40 machine screw.
It is possible to control directional headlights that switch along with the motor. Just connect the headlight lead to the “hot” armature terminal for the respective direction. The other headlight terminal normally connects directly to the chassis.
Dimensions: 2″ x 1.7″ x .8″ high