hot switches [TANKS]

["Chrysanthos Kanellopoulos" <xchrysk-at-otenet.gr>]

Thank you all for your kind advice and your interest.

Frank,   I am using this half moon relay, attached here. (also in my message of Dec. 24, 2006). The half moon is a metal plate, either iron or brass. The poles (switches) are two tiny ball bearings.

Black is for negative and red for positive. There's one mistake in the diagram: Both negative and positive go through the speed control.

 No,  I don't seem to have a short circuit with all the catastrophic events.  The tank runs for about 20 minutes before the half moon part and switches get awfully hot.  Nothing else gets hot.  The speed control stays cool.

I am using grease on the half moon plate , as in mechanical speed controls, so it can slip smoothly over the switches.

I like Mike's solution of CO2 dripping constantly on the system !

Chrys

 

 

 

 

believe Chrys is referring to the servo-operated microswitch solution shown in
http://www.rctankcombat.com/articles/speed-control/05MAGSideMounted-large.jpg

If the setup is hot with both switches idle, then you have a short through the
structure.  Check everything with an ohmeter, e.g. inside the switch mounting holes
to all the terminals.

If not, activate just one switch and see if the heat is only on that side (hold your
finger on the active switch until it makes you shout "Ouch!" or worse).  You may be
exceeding the capacity of the switch.

Also check the wiring.  It's unlikely you have a dead short because that would cause
some catastrophic symptoms, but you may have a very thin conduction path.

Regards,
  Mike Lyons

P.S. You could use a little CO2 bled constantly to freeze it all down.  No?  Why
solve the tough problem when you can come up with a fun solution!


---- Frank Pittelli <frank-at-rctankcombat.com> wrote:
> Chrysanthos Kanellopoulos wrote:
> > you might smile with my ignorance, however I must report that I used the
> > half moon relay as described in the 'how to Articles' page, and the
> > switches just get very hot with 18 V - 6 Amps.  They get so hot to a
> > point that their plastic parts melt down. The grease I used on the half
> > moon disk and relays gets so hot that it burns and when I open the hatch
> > of the tank it smells like a burnt hamburger! I then replaced them with
> > brass switches, but they still get hot.
> > What am I doing wrong?
>
> Not sure which circuit you mean by "half moon relay" and really not sure
> why there is any "grease" involved in an electrical circuit.  So please
> attach a simple drawing of the circuit, including the battery, switches
> and motor. It sounds like you have a dead-short of some sort in the
> circuit, which we should be able to determine from the diagram you send.
>
>       Frank P.

half moon.jpg