Re: newbie [TANKS]

[Bill Hamilton <seeker-at-phoenyx.net>]

On Sun, 3 Apr 2005, Tim Hansen wrote:

>
> ok, i was looking at the control systems and DAMB! this is confusing! 
> its like a foriegn language. what the heck is a relay? i was looking at 
> the Anvilus mini relay controller and it says to wire two relays to 
> every motor. whats a relay, whats it do, and why do i need them? why 
> cant this be as simple as rc cars? battery, motor, ESC, and radio are 
> all you need. i am completly new to wireing electronics. is there an 
> easier way out just to get my tank moving? or mabey someone can school 
> me?

Unfortuately, typical R/C electronics can't handle the kind of power 
needed, and will let all their magic smoke out.  The relay-based control 
systems are homebrewed speed controls that can handle the power 
requirements.

A relay is an electronically controlled switch.  You provide a small 
current to an electromagnet in the relay, and it pulls the switch closed 
(or open, depending on the relay).  Turn off the current, and it opens (or 
closes) the switch.  It is much like a power transistor, only much more 
primitive and much less finicky about little things like heat dissipation 
and static and electrical noise in the system.  Basically, the idea is 
that you use low power, cheap to construct circuits to do all your signal 
processing, then use the outputs of those circuits to drive the relays 
that control the high-power motor circuits.


-Bill Hamilton