Now that I am retired cost is a concern. Does anyone make their own decoders from components and where did you get the schematics? What was your cost? Thanks
I have not done it. I have a feeling that it is not going to be very cost effective. The components won't cost much but you'll need to have the boards fabricated or buy them from someone, and you'll need a programmer for the processor. Did some Googling:
http://www.merg.org.uk/resources/dcc.htm
There are some examples of accessory decoders where size is not so much of an issue, which might be possible to do at a reasonable cost. Still need a programmer, though.
Jeff But it's a dry heat!
The tooling required to fabricate multiple layer PC boards and assemble surface mount components would far outweigh any cost savings of trying to make your own decoders. A conservative estimate would be in the range of $5,000 in tooling. And you still must program the microprocessor used on them, which is likely to cost hundreds of dollars for the software alone.
Decoders are assembled and programmed on computerized, robotic assembly lines.
That me be the state of the art but there is no reason the components can not be hard wired. Making a printed circuit card can be done with ferrous chloride solution. I've done it when TTL logic signal circuits were published in MR.
The required parts for a HO scale basic decoder are considerably smaller than TTL components. I have done TTL and SMT. With SMT, you have a real challenge. Go though the Digi Key and Mouser online catalogs. They have loads of SMT components. Good luck. You will need it, steady hand, lots of patience.
Programming the decoder cpu will be another challenge. Don't even talk sound.
A stationary decoder is possible.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
There is also a DIY decoder design here:http://www.fremo.utwente.nl/selfmade_decoder/decopic_e.html that includes instructions on how to assemble it without a circuit board by soldering the components to each other.
That second one is quite impressive, but even so, much as I love to build electronics circuits, I don't think I'd want to build up enough to outfit a 20+ loco fleet. Stationary decoders, on the other hand..I've built several of Hans Deloof's LocoIO, depending on which parts I put in I can get it to around $1 or less per bit of I/O. And since there's no size requirement with a stationary decoder, there's no need to use SMT techniques and such. $12 seems cheap vs that admittedly very nifty loco decoder.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.