Voltage regulator

[todd israels]

At 01:17 PM 1/3/99 EST, you wrote:
>In a message dated 1/2/99 10:16:02 PM Pacific Standard Time,
>clarencewood at centuryinter.net writes:
>
><< Following this thread with great interest!  What is PWM?? >>
>
>PMW is Pulse Width Modulation. In motor control it is fantastic. It is used
>for controlling speed and torque on motors. It is the backbone of the
>machining industry. We have motors with encoders that control the velocity of
>the tables on milling machines at exact speed to acurracies of 0.0001 inch or
>less and can achieve velocities from 0 to over 1000 inches a minute without
>losing position. Computer control allows three or more to be used to contour
>with accuracies stated before. All this with constantly varying load for the
>cut and the weight of the parts. Also used in printers and plotters.
>it is an on/off switch of the power at a constant (usually) voltage kind of
>like if you using a thermostat to keep a constant temperature in your house.
>Just a thermostat for speed or in this case, pressure. Simple idea but the
>control can be fantastic in use. Has anyone started on a pressure switch
>controlled PMW drive. I would love to play with it. Maybe even machine some
>parts if need be.
>
>Fred Harmon
>Fred Harmon Precision Machining
>
>
	I have also been following this thread.  Yes PWM is a great way to control
a motor, especialy if accuracy in speed or position is required.  This
would be of great advantage if the return line to the tank can be
eliminated by using PWM and a presure sensor.  
	There was a control modual mentioned that droped 2.4 volt at low throtel
openings and could be made very simply with 3 or 4 rectifier diodes in
series and a NC (so failure wont cause fule starvation) relay contact.
Energize relay at low throtel openings.  To activate use a microcontroler
or a simple opamp 1:1 for isolation and low load and a second opamp as a
comparitor to trigger.  
	On an unEFI note Fred do you have a simple motor speed controler that has
PWM output and +10,-10 volt signal input?  This is for personel
experimentation with a Galil Motion card(scraped due to bad axis) and cheap
DC motors and surplus encoders.  Simple and cheap are the main objectives,
to leave more resources availabe for program development.  

				Todd Israels