WHEN: Most Friday evenings. TIME:

28 January 2008

Transistor conversion of Economy controller - part 1

Inspired by Erlo (along with disappointed enquires from Jacques and Gordon ;-) and the success both Erlo and I have had with the inexpensive Euro True Scale controller circuit last year, I revisited the previously unsuccessful Parma economy controller conversion for Phil, on Saturday afternoon, with the emphasis on quick build. The offending metal frame was thrown out, the trigger opened up slightly to fit a bigger tube (was even quicker to do than explain ;-) and the result bolted to a single PC board (any thin board would do, with an after-market wiper board added) with the significant advantage of an intermediate anti wobble nut clasping the board solid, which extending the useful bottom cut out in the Parma economy Nylon trigger easily facilitates.

The result was the same knife through melted butter feel I enjoyed on mine with the brush wiper last year and a layout that has little or no chopping up of the controller case (something I hate), with the spring post, brake stop and full throttle stop 3 bolts simply bolting right through the case to hold the board in rock solid. Version two will have the 12 band board mated to it for a total in the case wiper board fit and then to try charm uncle Craig to knock me off some new spec 12 band boards or maybe even one single all encompassing board. This could then mean one could offer a really simple and compact (even if not very pretty) self build option for all those folk who wave Parma economy controllers at us, hoping for a miracle. The transistor R35, brake pot R26, and sensitivity pot R15 make for a simple single board conversion that club members could do for themselves on existing units with a nylon trigger upgrade, or for all up cost under R500 including a new Parma nylon trigger economy controller........

There will also be old defunct 16D motor brush box units lying around with us changing to Falcons, so one can easily switch from normal wiper button to magic wiper brush ;-)

Ideal for all the classes we now will run at Ecurie although fine with 16D as well. Sceptics should note mine with the same less heatsinked transistor located in the handle coped fine with my whole team of newbies for the whole of the 1.5 hour social enduro.

Once the electrics are in and things sorted, I will load on the blog a version 2 board scan for tracing and local SA component links for easy reference, including the Hella (from Akals) R30 relay option I have enjoyed with 100% reliability for a year. The only extra tools I needed were a Dremel and electric screw driver for careful drilling, along with a Saturday afternoon.

Yup, a Turbo, Slotwiz or Slotworks it is not, but just as competitive for club racing. Part 2 will have the component sources plus base board outline.

The circuit used is from these interesting sites, which are well worth a surf and the drawing is tweaked appreciatively from the first site, which features the popular German circuit:

1 comment:

Green Machine said...

Hi I am busy building a transistor controller using a Ninco handle as a base. For my next version I would like to use a Parma. where do you obtain yours ? Greetings John