WHEN: Most Friday evenings. TIME:

21 July 2010

MRRC controller with 1/24 HD30 UPGRADE PCB

The rash of new visitors to Ecurie provides the enjoyable dilemma of how to kit them out with cheapie controllers. Amazing how folk take to electronic controllers once they have driven with them!
Both the Parma Turbo (Plus) unit and the newer MRRC unit provide an excellent base at reasonable cost. Difalco products are Rolls Royce and there is a present window of opportunity to purchase the new 30 band wiper boards complete with resistor banks at an excellent value price. Add two 20 ohm pots and a Tip 36c transistor for pennies and you have a stunning combination for club racing at well under a grand.
The unit above was assembled with the transistor soldered direct to the board and has tested well but not used in track action, yet. Feels luverly, though ;-)
Soldering the unsupported transistor direct to the board is neat but dubious without additional support (see under the right potentiometer) - that may be added later, if necessary. The rest of the soldering reduces to a simple six joints, using this gorgeous board. Reference to the previous posting reveals that there are a host of resistor bank options for the Tip 36c, although experience has shown that the 113 ohm bank will probably be the most suitable.

There will be a latter blow by blow once testing is complete but, in the meantime, these are the sources I used for the various components:

2 x 20hm potentiometers (loudspeaker volume controls) for brakes and start adjustment @ R30 each:

Tip 36c transistor at R20 a pop, from most electronic shops:

Difalco upgrade board with resistor bank from various online sources, or even direct from Difalco, at approx R400 (this one is 148 ohm):

MRRC controller base (normally sourced from Pendleslot for GBP25, under accessories) at approx R300:

That makes for an all up cost of about R800 for a larney controller and you can brag to your mates about the smooth as silk 30 band action......!

Scroll back through previus blog posts for the circuit but remember only to connect to the brake stop, never the brake band.