Hi all,
So, not surprisingly, I'm having voltage control problems again. This time, I want to use a JFET (or any transistor, really) as a voltage-controlled SPST switch. I've read college papers, articles, and blog posts about it, but all I end up getting when I try it is obscure/bias/source voltages, inversions, or no change at all between the input and output.
I know I'm a noob and I'm probably just screwing things up, but does anyone know of a sure-fire way to do this? What I find really embarassing is that I once wrote an article on making an analogue bitcrusher which used a JFET-based voltage-controlled switch, and I can't even get that to work anymore (it did at the time).
If you are curious as to why I need this, I want to use it for routing audio. I have a couple ideas, such as sequentially selecting outputs from my multi-waveform oscillator, and routing audio within a filter for interesting multi-timbral effects.
As an example, here's a small list of the places I've been trying to figure this out:
http://www.allaboutcircuits.com/vol_3/chpt_5/2.html
http://answers.yahoo.com/question/index?qid=20080127204831AAIynpw
http://www.circuitstoday.com/wp-content/uploads/2009/08/jfet-as-analog-switch.jpg
http://en.wikipedia.org/wiki/JFET
http://www.geofex.com/Article_Folders/bosstech.pdf
http://ist-socrates.berkeley.edu/~phylabs/bsc/PDFFiles/bsc5.pdf
http://www.premierguitar.com/Magazine/Issue/2007/Jun/JFET_Switching.aspx
http://stinkfoot.se/archives/503
http://sub.allaboutcircuits.com/images/quiz/02094x01.png
http://www-g.eng.cam.ac.uk/mmg/teaching/linearcircuits/jfet.html
Thank you for your help.
So, not surprisingly, I'm having voltage control problems again. This time, I want to use a JFET (or any transistor, really) as a voltage-controlled SPST switch. I've read college papers, articles, and blog posts about it, but all I end up getting when I try it is obscure/bias/source voltages, inversions, or no change at all between the input and output.
I know I'm a noob and I'm probably just screwing things up, but does anyone know of a sure-fire way to do this? What I find really embarassing is that I once wrote an article on making an analogue bitcrusher which used a JFET-based voltage-controlled switch, and I can't even get that to work anymore (it did at the time).
If you are curious as to why I need this, I want to use it for routing audio. I have a couple ideas, such as sequentially selecting outputs from my multi-waveform oscillator, and routing audio within a filter for interesting multi-timbral effects.
As an example, here's a small list of the places I've been trying to figure this out:
http://www.allaboutcircuits.com/vol_3/chpt_5/2.html
http://answers.yahoo.com/question/index?qid=20080127204831AAIynpw
http://www.circuitstoday.com/wp-content/uploads/2009/08/jfet-as-analog-switch.jpg
http://en.wikipedia.org/wiki/JFET
http://www.geofex.com/Article_Folders/bosstech.pdf
http://ist-socrates.berkeley.edu/~phylabs/bsc/PDFFiles/bsc5.pdf
http://www.premierguitar.com/Magazine/Issue/2007/Jun/JFET_Switching.aspx
http://stinkfoot.se/archives/503
http://sub.allaboutcircuits.com/images/quiz/02094x01.png
http://www-g.eng.cam.ac.uk/mmg/teaching/linearcircuits/jfet.html
Thank you for your help.