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From: "Phil Allison"
References: <email@example.com> <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org>
Subject: Re: Help - Power mosfets - difficult load
X-Newsreader: Microsoft Outlook Express 5.50.4522.1200
Date: Tue, 29 Oct 2002 10:26:27 +1100
NNTP-Posting-Date: Tue, 29 Oct 2002 10:17:32 EST
Organization: Telstra BigPond Internet Services (http://www.bigpond.com)
"Bill Allison" wrote in message
> "Phil Allison" wrote:
> > ** I don't think you have any idea what a glitch is. It may last
> > 1/10 of a second - not enough to barely move a servo but enough to
> > fets.
> Your idea of what a glitch is corresponds to the last generation of RC
> kit, when servo positions were transmitted in PPM frames modulated
> onto the rf and got to the servo more or less directly (via receiver
> and demultiplexer). Signal reception quality would affect pulse width,
> dramatically at the limits of radio range.
** Glitching with PPM can occur at any range - other RF signals and
electrical noises do the job beautifully.
> For the last time - modern microcontrolled RC receivers DO NOT rely on
> quality of rf link. The pulses output to the servo are generated
> locally. The pulse width defaults to that defined by the fail-safe
> rules programmed into the receiver by the operator. When an error free
> PCM data stream is received via the fm rf link the pulse-width
> generated is then that commanded. (That's the simplistic version,
> there's somewhat more sophistication than that). Not a single frame
> deviates from that behaviour.
** When the PCM data stream becomes corrupted a brief clitch can be
produced as the software recognises the error - you would need a CRO so see
it on the PPM signal - or your fets will let you know.
. . . . .............. Phil
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