Alt-BEAM Archive
Message #00944
To: BEAM List beam@corp.sgi.com, Richard Piotter richfile@rconnect.com
From: dennison dennlill@buffnet.net
Date: Wed, 24 Feb 1999 14:47:48 -0500
Subject: [alt-beam] Re: what's 'strobe'
True, but with pwm you can typically get the same amount of work done, but
at lower power requirements.
Dennison
>Switching uses power. In an average CMOS (I know this for sure), there is a
>point part way through the switching where the FETs are both on
(Complimentary
>Metal Oxide Semiconductor (using field effect transistors paired up)). When
both
>EMOSFETs go on, they essentialy are the equivalent of tying a small
resistor
>from (+) to (-), effectively draining a little power. The more you switch
such a
>strobe, the more energy it's going to draw, simply by the process of
switching.
>Important consideration there. Good luck.
>
>dennison wrote:
>>
>> Exactly! Using another bicore lets say, you could 'strobe' the enable
line
>> for the 74xx245. This was you would in effect have PWM for the motors you
>> drive. So yep, your right. This can be used to change the speed of motors
>> depending on lets say the light level.
>>
>> dennison
>>
>> >This is a little question for Dennison:
>> >
>> >In your e-mail of 17 feb (walker with reverse in one chip; I deleted it
so
>> >I can't copy the text in this message) you wrote something like:
>> >
>> >'strobe' the enable inputs of a 74x245.
>> >
>> >Do you mean something like PWM by means of an extra bicore with
>> >photodiodes, with a relatively high frequency?
>> >
>> >Sorry for my lack of knowledge of the English language.
>> >
>> >
>> >Wouter Brok
>> >
>> >
>
>--
>
>
>Richard Piotter
>richfile@rconnect.com
>
>The Richfiles Robotics & TI web page:
>http://members.xoom.com/richfiles
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