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View Full Version : Another "Is this possible? " question



Lagg
01-28-2006, 05:26 AM
I was wondering if makeing a pulse like this is possible with a basic stamp.

http://scry.badsyntax.net/images/pwm.jpg



Each of those "steps" being of a different frequency.

(I really have no idea how to generate such a thing anyhow, but I thought it maybe easier with a stamp)

Mike Green
01-28-2006, 07:57 AM
You need to give more information like the time scale and voltage and current range. From the label "STEP CHARGING BEGINS" it sounds like you're charging something like a capacitor or rechargable battery. The outputs of a Stamp are strictly +5V/0V and limited in how much current they can switch (about 20ma). You will likely need external circuitry to do the actual switching of the power, but the Stamp can provide logic level pulses to turn the switch on and off (look at PULSOUT command). It can also provide a voltage reference to set the output voltage and/or current (look at PWM command). You can also drive external devices to produce the control voltages.

Jon Williams
01-28-2006, 08:55 AM
Checkout the PWM instruction -- that might do the trick for you.

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Jon Williams
Applications Engineer, Parallax

Lagg
01-28-2006, 03:27 PM
Thanks

Lagg
01-29-2006, 05:43 AM
I looked into the PWM command

I found some stuff and I was wonder if paring this piece of code




counter var word

do
for counter = 255 to 0
pwm, 12, counter, 1
next
loop





with this
diagram

www.emesystems.com/images/bs2/BS2PWM2.gif (http://www.emesystems.com/images/bs2/BS2PWM2.gif)

would do what I'm what that picture is showing?

And yes, it it for charing something via toroidal coil.

Tom Walker
01-30-2006, 11:54 PM
Keep in mind that the Stamp's PWM is not "true" PWM but can perform the same function in certain situations with additional hardware to integrate (smooth out) the signal. This is covered in the documentation.

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Truly Understand the Fundamentals and the Path will be so much easier...