| NMRA DCC Controller for Model Railroad |
Motor Control
EFM Control Method
The reverse voltage of motor are in proportion to number of
revolutions. Thus, number of revolution is controlled into designated
speed according to measuring reverse voltage while pulse off duration.
For achieving speed stability and low noise, three kinds of pulse below are used.
Low Speed
Pulse drive is only way to perform slow motor rotation. Our decoder adjusts pulse off duration every time , so smooth slow running with low noise is possible. Best low speed running without loud motor noise is able to be performed according to match this pulse off time with motor characteristics.
Ultra Low Speed
When speed is changed from step0 to step1, the vehicle will start suddenly. It is different from real train which has heavy weight. So we equip two functions for decoder.
(1) Slow up & down Speed Change
When speed step is changed, speed step is slowly changed with finer step than 126 speed steps. This function will make acceleration smoothly when the vehicle starts or runs at other speed.
(2) Ultra Low Speed Pulse
EFM pulse has limit low speed for running stably. So, ultra low speed pulse performs ultra low speed running. But this pulse acommpanys vibrations, so this pulse is used only in lower speed than step1.
Mid or High Adjustment
When mid or high speed, the vehicle can run more stabler compeared with the case of low speed originally. So frequent speed check is not needed. Thus, pulse on dulation can be longer. For that, motor noise will be lower. Actually pulse duration is gradually longer.
Thin Pulse Mode (Only for core less motor)
The model vehicle is made brass into makes more motor noise caused by EFM pulse than the model vehicle made plastic into. The vehicle equipped with core less motor which has low inductance coil is that reverse voltage duration is very short. In this case, pulse off duration can be shorter. This mode is only for mid or high speed. low speed running needs normal EFM pulse. This mode is only for core less motor. Must not use this mode for cored motor.
Preset Value
Motor adjustment has to set many CVs. So, adjustment is troublesome. Then there is preset value. When motor type is set to CV47, appropriate value is written. Please try to run the vehicle in this state. If there is problem, please adjust each CV.