PWM

Discuss mods, hacks, tweaks, etc.

Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.
Locked
303user
 

PWM

Post by 303user »

Hey Limor & The Gang, any way of adding PWM? I'm guessing that a resistor somewhere changed for a pot would allow variation of the Pulsewidth?
That'd be mucho funkio! So whuch resistor controls the pulsewidth????

Guest
 

Post by Guest »

r45 can be varied to give some modification of the pulse width
but the amplitude also changes
there isnt a real simple way of doing pwm with the circuit

try replacing r45 with a 50k pot with a 1k in series

303user
 

Post by 303user »

Ahh, I see. What about also adding a pot to increase the level of the VCO, this would then allow the amplitude change to be compensated for and also possibly overdriving the VCF. Feasable?

Guest
 

Post by Guest »

r62 controlls the signal seen by the vcf
try replacing this with a 500k in series with a 50k

Jonnay
 
Posts: 142
Joined: Thu Jun 02, 2005 12:28 pm

Post by Jonnay »

Check this out.

http://machines.hyperreal.org/categorie ... ircuit.txt

Assuming you set the waveform to saw, and interposed this circuit between the filter, it might work with some modifications.

You're probably going to have to muck about with the resistor values because they're using a 15 volt supply, while the x0x has a 12 volt. Also, the output voltage on the PWM unit is +5V to -5V, while the x0x is expecting a range between +5 to +9 or +6 to +11 depending on the waveform you selected.

Locked
Please be positive and constructive with your questions and comments.

Return to “x0xm0dz”