FW: PWM - acronym definition request

[Atkinson, David]

Hi Joe.  The acronym stands for:

Pulse Width Modulation.  By varying the duty cycle of a signal, you can
control the amount of time it is off vs. the amount of time it's on and
thus control the effective power output of the signal.  PWM has many   
uses,
such as controlling the power applied to electric fuel pumps on some   
newer
cars (to effectively lower the fuel pressure at low rpm/high vacuum),   
controlling
the wastegate for forced induction apps, etc.  Rat Shack had a good book
long ago on 555 timer ICs, don't know if they still have it, but it's a   
good
place to learn about PWM - I think they had a light dimmer circuit that
used a 555 to vary the duty cycle to a FET or something (it's been a long
time).  Hope that helps.

 Dave

 ----------
From:  Joe Boucher
Sent:  Thursday, October 16, 1997 9:54 AM
To:  diy_efi
Subject:  PWM - acronym definition request

While looking through some old posts, I came across the acronym PWM in
association with turbo control.  I suspect it is an inline valve in the
wastegate vacuum control line.  But can't figure it out on my own.

What does the PWM acronym stand for?

Joe Boucher
'70 RS/SS Camaro  '81 TBI Suburban