Hero999 said:
I understand that but I thought you needed to control the trains independently from one another which is only possible if you use three H-bridges and at 4A per channel the L6203 is perfect.
Yes I do need to control the trains independently, but not with three H-bridges, only with one.
I think the problem is that nobody here is familiar with DCC in Modelrailroading.
DCC basically places a bipolar signal on the track that is used for both controlling the engines using 8- and 16-bit packets and delivering those at +/- 24 volts and enough current to operate all the motors, lights, smoke, sound etc. on the trains.
The packets consist of an 8-bit address - a different one for each engine of course, and additional 8- and 16-bit packets to control direction, speed, acceleration, deceleration, whistle, bell, etc etc.
The DCC packets are generated by a specialized unit called a Central Station (although PC implementations are available as well) and one then needs a DCC Booster to increase the DCC packets to a voltage and current level sufficient to drive all the trains on the layout.
DCC basically combines the control and the power to run the trains into one single control signal.
With DCC it's no longer necessary to divide the layout into electrical blocks with lots of wiring and controls, the Central Station encodes the information to be sent to each engine and the decoder in each engine responds to the information sent to its specific address.
I do have schematics for a 10 amp DCC booster that uses discrete components, but I was hoping to be able to come up with a design that uses a lot fewer components, like basically a 15-amp integrated H-bridge and a simple microcontroller for the few functions required.