Only minor space requirements due to just 11 parts
The simple circuits providing a
5V stabilization were a poor design in two aspects. The bridge rectifier
caused quite a lot of loss of voltage which resulted in useable illumination
only above 7V on the tracks and high power dissipation above 15V.
A completely different concept is shown in the circuit on the left. The bridge rectifier was replaced by Schottky-diodes featuring an extremely low voltage drop and voltage control was replaced by current control using a LM334 as a power source.
In result the LEDs light up constantly at already 4V and the circuit does not produce any waste heat. On top, short power outages of up to 0.8 seconds are ironed out by the capacitor.
A completely different concept is shown in the circuit on the left. The bridge rectifier was replaced by Schottky-diodes featuring an extremely low voltage drop and voltage control was replaced by current control using a LM334 as a power source.
In result the LEDs light up constantly at already 4V and the circuit does not produce any waste heat. On top, short power outages of up to 0.8 seconds are ironed out by the capacitor.
Inspired by an
old picture showing a car transport along the Hindenburgdamm,
the LGB 4x59x flatcars were declared to be car transporters and one of these
was equipped with a tail light.
Circuit mounted underneath the chassis
Functional test passed !
LEDs and interior illumination
A minor modification of the circuit shown above allows for operating some more LEDs. Some outputs which were adjusted to meet the connected LEDs requirements were added to the final stage. Three 1.3cd LEDs and two 0.9cd LEDs were used to illuminate each of the units shown in the picture below. Since the LEDs are running at only 90% of their nominal voltage, the total power demand is just around 70mA.
A minor modification of the circuit shown above allows for operating some more LEDs. Some outputs which were adjusted to meet the connected LEDs requirements were added to the final stage. Three 1.3cd LEDs and two 0.9cd LEDs were used to illuminate each of the units shown in the picture below. Since the LEDs are running at only 90% of their nominal voltage, the total power demand is just around 70mA.
The light's colour inside the railcar deceives the camera - a question of a correct white balance.
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