The decoder can build with DOD (device on device) technique without PCB (size: 11 x 6 x 3 mm, cost: ca. 5-10$).
All pieces are SMD and can be soldered in distance (H-bridge on motor etc.).

Picture gallery:
Construction with PIC12CE519/SM as picture gallery as VRML and ZIP files.
Construction with PIC12CE519/SN as picture gallery as VRML and ZIP files. (smallest size)
Device on device decoder with nomal SMD PIC
Device on device decoder with smallest PIC
ROCO Köf III
Carlo Zamboni (ROCO E412,E646)
Z-Lok with decoder
Lars Lundgren (TMW)

This pictures were friendly made by Michael Maryschka.
A free VRML-viewer can be downloaded from http://www.parallelgraphics.com/htm/en/prod/
VRML Clients -> Cortona -> Download Cortona


Build construction: minidecoder for analog motor

Z-diode wire bend 90° and cut.
Marking together, move under pin's of PIC.
Pin 1 & 8 bend over diode wire, solder.

Bend diode bridge minus straight ahead, all other flat on chip.
Move diode bridge with plus to marking Z-diode.
Solder minus at Pin 8.

Turn, PIC left - diode bridge right.

Bend plus from diode bridge over Z-diode.
H-bridge Pin 3, 5 & 8 bend straight ahead, cut pin 3, bend all other flat under.
Cut pin 1, 2 & 4 at lower edge of IC.
Cut PIC pin 5.
Put H-bridge with marking to left/front (45° slope to front) at top of PIC.
Pin 6 from H-bridge under PIC pin 7 and pin 7 from H-brigde under PIC pin 6.
Bend pin 6 & 7 from PIC to H-bridge pin 7 & 6 and solder.

Put 470 Ohm resistor between plus from diode bridge and Z-diode/PIC pin 1 and solder.

Connect with copper varnish wire pin 1, 2 & 4 of H-bridge with minus diode bridge.
Let wire longer to pin 1.
Scrape copper wire on to solder places with knife, or better thin round file, the varnish, then solder.
Please be sure that no contact to pin 3 exists.

Solder 2,2µF/20v condensator, marking to plus diode bridge.
Contact from pin 3 H-Bridge to plus diode bridge, please be sure that no contact from pin 3 to ground exists.
Cut copper varnish wire in correct length, hold with pinzette and solder ends.

Cut pin 2 & 3 of PIC and bend a little bit between.
Bend middle pins of MOSFET under.
Solder MOSFET with writing inner and marking to condensator of pin 2 & 3 from PIC.
If writing not readable, rub on paper.
Solder one pin, align Pin's, solder second Pin.

Solder 10kOhm resistor at high position as possible (one on plus, one on minus from diode bridge),
then solder 100kOhm resistor (smallest size) at lower AC pole from diode bridge.

Contact with copper varnish wire from PIC pin 4 (cutting) to 100kOhm.
Bend wire from H-bridge pin 1, 2 & 4 to middle/middle MOSFET,
solder middle pins.

Contact from upper 10kOhm resistor to PIC Pin 7.
Contact from lower 10kOhm resistor to PIC Pin 6.

Turn, solder 3,3µF/15v condensator, marking to plus diode bridge/Z-diode.

Solder motor to Pin 5 & 8 from H-bride.
Solder rail contact to diode bridge.
Connect light to open pins from MOSFET, other pole to plus or rail.

Function conrol.

Source of supply: Electronic parts or complete sets of decoder you can order from Andreas Bergmann or Joachim Katzer (Web).
Electronic distributors: Bürklin | Conrad Electronic | Future Electronics | Ineltec | Insight | Mütron | Reichelt | RS-Components | Spoerle |