Does anyone understand why these devices provide such a long run-time in the absence of the DCC track power?
I have opened one up and can see that the circuit is more complex than the "traditional" one I am familiar with - of Capacitor(s), diode and resistor.
It contains 6 off 0.47uF 2.7 volt capacitors in series. There also appears to be a resistor ladder, with each capacitor connected in parallel to one of these resistors - I take it that this is to ensure an equal/controlled voltage (and therefore charge) for each capacitor. There are also several other components which I cannot identify - nor is it clear as to how they are interconnected.
The most powerful devices I have made contain 3 off 0.47uF 5.5 volt capacitors in series. In principle, therefore, my device should provide twice the endurance of the DCC Concepts device. In fact, I get less than 1 second of running after the track power is lost, whereas the DCC device runs a loco for several seconds.
I would appreciate any insight anyone can add.