Re: Joe Sommer/Anvilus [TANKS]

["Milenko" <milenko-at-king-nerd.com>]

The mini is like an H-Bridge in that it only does Forward-off-Reverse.  It uses off-board SSRs or Auto Relays to achieve this.  It's an electronic version of what some people have done with servos and mini-switches to control relays.

 

The RC Relay Motor Controller from Anvilus does Forward-off-Reverse all on it's own.  It has onboard Relays so you can just drop it in and it works.  It also supports PWM with offboard SSRs.  In this case, the onboard relays act as an H-bridge to control motor direction while a set of offboard SSRs provide the pulsing to control motor speed.  SSRs must be used because they contain no moving parts and can react very quickly.  Anything with moving parts will have a difficult time pulsing at (I think - I could be wrong about the number) up to 200 times per second.  The contacts would very quickly burn out from arcing as well.

 

Jeremy

----- Original Message -----

From: Toast

To: tanks-at-rctankcombat.com

Sent: Friday, April 07, 2006 8:59 AM

Subject: RE: Joe Sommer/Anvilus [TANKS]

I'm totally stunned.  When I said this:

> I thought the Anvilus Mini did proportional control.  I thought it decodes
the signal from your radio equipment and gave a 12v DC PWM output meant to
control high amp relays.  You are however telling me this isn't true?

 

I fully expected you to correct me and explain why.  I really though we
where having a small communication problem and that's why I asked the
question.  So in watered down terms, is the Anvilus controller (mini or
otherwise) just a fancy H bridge?  It's just there to mix?  Can you explain
what exactly it does because now I'm confused?

 

If you try to PWM a mechanical relay I would imagine you would soon destroy
it due to arcing at the contacts.

 

Arching had never occurred to me but I guess they'd heat quickly and burn
up.

 

I've been working this whole tank thing out in my head and some on paper but
I've not started building yet.  I'm the kind of person that wants to know
everything I can possibly know before I put hammer to nail or a driver to a
screw.  What is the easiest path to proportional speed control?

 

 

  _____  

From: tanks-admin-at-rctankcombat.com [mailto:tanks-admin-at-rctankcombat.com] On
Behalf Of Steve Tyng
Sent: Thursday, April 06, 2006 8:23 PM
To: tanks-at-rctankcombat.com
Subject: RE: Joe Sommer/Anvilus [TANKS]

 

 
Toast wrote:
 
> It does occur to me that
heavier plating on the Mini would help it stand up to that stated 150ma max
current draw for longer before giving up the magic smoke.
 
If you exceed the 150ma the driver chip will give out the magic smoke, not
the board traces.  I know from experience.
 
> I thought the Anvilus Mini did proportional control.  I thought it decodes
the signal from your radio equipment and gave a 12v DC PWM output meant to
control high amp relays.  You are however telling me this isn't true?
 
Correct, the Mini does not do PWM.
 
> But if we are making the distinction like you are
making then I'd have to ask, if I did use just plain old spring loaded
magnetic coil type relays like they teach you about in early electronics
courses and not solid state ones, wouldn't they NOT be able to cycle fast
enough for PWM applications?  Don't they have a maximum trigger frequency
some what decided by the weight of the switch mechanism they use?  Is this
maximum frequency listed on their spec sheets?
 
If you try to PWM a mechanical relay I would imagine you would soon destroy
it due to arcing at the contacts.
 
 
Steve