[Diy_efi] analog to pwm

Fri Feb 25 14:30:51 GMT 2005

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In a message dated 25/02/2005 14:11:55 GMT Standard Time,  
michael at fastmail.ca writes:

IMHO the  best way to do this is simply to get a voltage to frequency 
converter  chip. Although not strictly PWM it does work for a boost 
controller. This  was one of my first designs before I did one that was 
fully  digital.

-Michael

> I need to change an analog  0-5v  signal to a pwm signal to control a
> boost controller. how do I do  it?
> can any one help
> thanks Brent

A VFC chip will produce a variable frequency output but it is likely to be  
at a constant duty cycle, which by itself would be useless.  Try following  the 
VFC chip with a one-shot like a 555, that should do the trick.

Will Cowell
G0OPL

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<DIV>In a message dated 25/02/2005 14:11:55 GMT Standard Time,=20
michael at fastmail.ca writes:</DIV>
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  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>IMHO the=20
  best way to do this is simply to get a voltage to frequency <BR>converter=20
  chip. Although not strictly PWM it does work for a boost <BR>controller. T=
his=20
  was one of my first designs before I did one that was <BR>fully=20
  digital.<BR><BR>-Michael<BR><BR>&gt; I need to change an analog&nbsp; 0-5v=
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  signal to a pwm signal to control a<BR>&gt; boost controller. how do I do=20
  it?<BR>&gt; can any one help<BR>&gt; thanks Brent<BR></FONT></BLOCKQUOTE><=
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<DIV></DIV>
<DIV>A VFC chip will produce a variable frequency output but it is likely to=
 be=20
at a constant duty cycle, which by itself would be useless.&nbsp; Try follow=
ing=20
the VFC chip with a one-shot like a 555, that should do the trick.</DIV>
<DIV>&nbsp;</DIV>
<DIV>Will Cowell</DIV>
<DIV>G0OPL</DIV></FONT></BODY></HTML>

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