Re: Prof. Sommer's Controller Review [TANKS]

[Frank Pittelli <frank-at-rctankcombat.com>]

chris barthelson wrote:
> 
> I don't exactly know what I want. The motors opperate on 24V so I'm 
> using two batteries in series to get this so what ever I need for this I 
> will get. Frank are you talking about the power that opens the relays? 
> And if so could you use a 9V battery or similar to open them.

OK.  You have a 24V "motor voltage" or "load voltage", which will be 
connected to the "load" terminals on the relay (30=COM, 87=NO and 87a=NC 
for a standard automotive relay).  You should be using a 12v "coil 
voltage" or "control voltage", which should be connected to the "coil" 
terminals on the relay (85 and 86 for a standard auto relay).

As stated in the last couple of emails, we (me and Joe) believe that you 
should be able to control a 24V load with heavy-duty automotive relays 
(albeit at a reduced overall lifetime) and therefore you can use the 
standard Tri-Pact circuit.  Of course, we could be wrong (nope, never 
happens?), in which case your relay will simply stay closed at some 
point.  In so, simply pop it out and pop in another.  It would probably 
also help to spend a few bucks more and purchase top-quality, heavy-duty 
relays (like 40amp Bosch or equivalents) instead of cheap surplus 
knock-offs, because the relay contacts are probably more robust.

So, give it a try.  I think we'll be doing the same for one or more of 
the new vehicles in Maryland in the next month, so you won't be the only 
one "giving it a go" (as our British friends like to say).

        Frank P.