Aristo RDC1 Motor Surging Mitigation

Aristo-Craft RDC1 Test Video - Now fitted with LED Lamps - by Ted Doskaris (Continued results from prior video at link:    • AristoRDC1LampVoltageTest   )

Be forewarned, videos admittedly were done with poor camera skills.

As before, the Aristo RDC1 is set up for testing interior lamp voltage using DC linear track power with an oscilloscope to observe the voltage waveform produced by the PIC processor DC to DC converter, but it now powers LED lamps (with current limiting resistors) in place of the factory incandescent ones. The RDC1, without body shell, is placed on Bachmann rollers which are set on the track. With factory incandescent lamps, there had been a peculiar anomaly resulting in motor speed surging when about 6vdc is at the track. With LED replacement lamps, motor surging was not observed as had been with the factory incandescent lamps when varying track voltage, including over its entire range. Changing track voltage polarity did not affect results. Aristo's factory incandescent lamps can be expected to draw about 70ma at 6vdc each when illuminated (warm), but when they are cold would be very low in resistance. It appears when the PIC processor DC to DC converter is attempting to "wake-up" at lower voltages (a condition at which it should not be expected to properly perform) higher current can result to the cold incandescent lamps, enough so to influence the motors' speed and vice versa - hence surging. LEDs don't have hot / cold characteristic like incandescent lamps, so they can mitigate the ill effects of the PIC Processor wake-up.