4 replies to this topic

[James Grandi]

Hey all,

My spare controller is a Difalco my father built using a kit, and I was looking at doing some work to it ( wanted to add one of the diode brake pots like on my Ruddock ) and while looking over the controller I realized there is no relay wired in, anywhere. I know next to nothing about controllers other than to keep them cleaned and replacing the clips every once in a while. Can anyone tell me what the downside would be of not having the relay? Or if I need one, how I would add one?

This is the controller referring to;

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[John Streisguth]

My first electronic controller was exactly this (recently I had it upgraded to Genesis configuration by Jim DiFalco).  The advantage of the relay is to bypass the path up the wire, through the contact in the controller (which can get oxidized...you need to keep this one and the brake contact clean as regular maintenance), then back down the other wire to the track.  If you use the relay in conjunction with locating the transistor and heat sink right at the drivers panel, you can then use much lighter wire going from there up to the controller.  It makes less weight that your arm has to hold up.

[JerseyJohn]

Also  James, transistors absorb voltage when fully saturated { full on } the down side is app a one volt loss ... another words .12 volts in, 11 volts out to motor. A blast relay , as John states bypasses the Transistor, delivering direct track voltage to the car.. The more volts to the motor, the faster it will go....

[Ramcatlarry]

The Difalco blast relay kit instructions should explain the instalation.

[Mike Walpole]

The full power contact in the coltroller bypasses the transistor so the only voltage loss is from the current passing through 6' of wire and across the full power contact.  All the blast relay does is shorten the electrical path to about a foot and reducing the I^2R losses by 1/6th.