thinking of making a pwm with my laptop. was wondering if i can use the audio out to drive a irf540 fet. ideas or a circuit would be a big help thanx

Quote from xxzeropiontxx on October 21st, 2012, 01:23 PM

thinking of making a pwm with my laptop. was wondering if i can use the audio out to drive a irf540 fet. ideas or a circuit would be a big help thanx

Certainly seems doable.  Not sure if you would want to use the speaker output or the line output.  I would think you could better match the impedance using the line output.

Create your waveform, calculate the gain you need to turn the MOSFET completely on and use something like a LM-358 to up the gain to where you want.  Do keep in mind the audio signal is sinewave-based and bipolar in amplitude, so gain and zero reference will need to be set to simulate square waves.

I found a few links:

http://www.dutchforce.com/~eforum/index.php?s=7e690c2202dbdd6e0aeb81740c232a88&showtopic=38643

Various circuit diagrams here:
http://www12.fairchildsemi.com/an/AN/AN-558.pdf

Audio Software:  
http://www.techmind.org/audio/#siggen
http://www.satsignal.eu/software/audio.html

Certainly a useful project to pursue ZP.  Let us know if you get something working.

Quote from Dog-One on October 21st, 2012, 02:29 PM

Quote from xxzeropiontxx on October 21st, 2012, 01:23 PM

thinking of making a pwm with my laptop. was wondering if i can use the audio out to drive a irf540 fet. ideas or a circuit would be a big help thanx

Certainly seems doable.  Not sure if you would want to use the speaker output or the line output.  I would think you could better match the impedance using the line output.

Create your waveform, calculate the gain you need to turn the MOSFET completely on and use something like a LM-358 to up the gain to where you want.  Do keep in mind the audio signal is sinewave-based and bipolar in amplitude, so gain and zero reference will need to be set to simulate square waves.

I found a few links:

http://www.dutchforce.com/~eforum/index.php?s=7e690c2202dbdd6e0aeb81740c232a88&showtopic=38643

Various circuit diagrams here:
http://www12.fairchildsemi.com/an/AN/AN-558.pdf

Audio Software:  
http://www.techmind.org/audio/#siggen
http://www.satsignal.eu/software/audio.html

Certainly a useful project to pursue ZP.  Let us know if you get something working.

thank you DOG. i have a program that i can control the pulse or wave  and have spent a lot of time and money  building circuits  i thought this would be less costly if i dont take out my laptop haha