[sdiy] Level Translation

[Tim Ressel]

Yo,

The application I have (PWM Multiplier, C. Anderton,
Jan/Feb 1981 Polyphony) can run the CMOS gates at 5V
with minor mods. I'll run the 1488 at +/-10V.

--TR

--- Scott Gravenhorst <music.maker at gte.net> wrote:
> Curious... Whaddaya gonna do, voltage divide the
> 0-15 down to
> 0-5 for input and stick a +/- 10V supply on the
> 1488?  Or run
> the 1488 at like +/- 15 and voltage divide the
> output?
> 
> Tim Ressel <madhun2001 at yahoo.com> wrote:
> >D'oh!  Duh! 
> >
> >This is why engineers have flat foreheads ... from
> >whacking them with their hands when the obvious is
> >seen. Look up an MC1488. Its a TTL to RS232 level
> >translator, and it has pretty much the SG circuit
> in
> >it. In fact, one could just use that IC to do the
> >level translation. Since I have 4 outputs to shift,
> >and the MC1488 is a quad, I think I'll just use it.
> >
> >Thanks to all who answered my query.
> >
> >--TR
> >
> >
> >--- Scott Gravenhorst <music.maker at gte.net> wrote:
> >> Ok, time for the list to give Scott another
> lesson
> >> in basic
> >> electronics, but here goes:
> >> 
> >> home1.gte.net/res0658s/levtrans.gif
> >> 
> >> Is my idea (that I still have not tested), part
> of
> >> another
> >> design.  My original need is to translate TTL
> levels
> >> to +/- 8
> >> volts.
> >> 
> >> The way I think it _should_ work is this:
> >> 
> >> Supplies: +v = 10 volts, -v is -10 volts.
> >> 
> >> Since the input is expected to be the output of a
> >> CMOS gate,
> >> I'm assuming it's valid levels to be 0 or 15
> volts
> >> and not
> >> much inbetween matters.
> >> 
> >> When the input is 0 volts, the input NPN is off
> and
> >> the it's
> >> collector should be at or near 10 volts.  This
> >> should cause
> >> the PNP to turn on which should in turn cause the
> >> output NPN
> >> to turn on.  The output NPN's collector should
> then
> >> be at or
> >> near -v or -10 volts.
> >> 
> >> When the input is 15 volts, the input NPN is
> turned
> >> on and
> >> it's collector should be close to ground.  This
> >> should cause
> >> the PNP to be off, which will then not supply
> base
> >> current to
> >> the output NPN, turning if off.  This allows the
> >> output NPN's
> >> collector to rise to near +v causing a +10 volt
> >> output.
> >> 
> >> 
> >> Ok, I'm here to learn, so tear me apart.
> >> 
> >> If this solution is totally noob, so be it, but I
> am
> >> also
> >> interested in a solution to this.  (I'd rather
> not
> >> use op-amps).
> >>  
> >> 
> >> Tim Ressel <madhun2001 at yahoo.com> wrote:
> >> >Yo, Can you spare a cup of neurons? I'm all
> out...
> >> >
> >> >This is something I've never been good at: I
> have a
> >> >cmos gate putting out a 0-15V signal, and I need
> to
> >> >translate that to +/-10V. I just can't seem to
> wrap
> >> my
> >> >move-addled brain around this today.
> >> >
> >> >TIA
> >> >
> >> >--TR
> >> >
> >> >
> >>
> >__________________________________________________
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> >>
>
>=========================================================
> >>  
> >> - What good are laws that only lawyers
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> >> 
> >> -- Scott Gravenhorst | LegoManiac / Lego Trains /
> >> RIS 1.5
> >> -- Linux Rex         | RedWebMail by RedStarWare
> >> -- FatMan: home1.GTE.NET/res0658s/FatMan/
> >> -- NonFatMan: home1.GTE.NET/res0658s/electronics/
> >> 
> >> 
> >
> >
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>
=========================================================
>  
> - What good are laws that only lawyers understand?
> - Government: The other religion.
> - The media's credibility should always be
> questioned.
> - Lambs who lie down with lions are lunch.
> 
> -- Scott Gravenhorst | LegoManiac / Lego Trains /
> RIS 1.5
> -- Linux Rex         | RedWebMail by RedStarWare
> -- FatMan: home1.GTE.NET/res0658s/FatMan/
> -- NonFatMan: home1.GTE.NET/res0658s/electronics/
> 
> 


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