John, Your initial description indicates that you may be using ‘miniature rectifiers feeding LED strips’. If you use a full wave (4 diode) rectifier circuit between track pick-up and the LED strip you already have what is required.. except adding of a resistor to vary the brightness. What can also be done to help reduce flicker is to provide a carry-over storage capacitor. Circuit wise this means to add a relatively large capacitor, rated for 25V and several thousand microfarads, using a 100 ohm resistor to limit charging current from the rectified track voltage and a diode connected to supply current from the capacitor toward the LED strip through the brightness adjusting resistor. This may be enough to eliminate annoying flicker.

DonV