<html><body><font face="Helvetica">Hardly diy, though. I put a fair amount of effort into getting the design to work well, so I thought it might be of interest to someone trying the same approach.<br><br>Ian<br><br>Sent from XFINITY Connect Mobile App<br><br><br>------ Original Message ------<br><br>From: Steve Lenham<br>To: synth-diy@dropmix.xs4all.nl<br>Sent: August 29, 2016 at 6:35 AM<br>Subject: Re: [sdiy] Odp: Re: SAW core VCO flyback time<br><br>Even more familiar:<br>http://curtiselectromusic.com/uploads/CEM_3340-3345_Long.pdf<br><br>:-)<br><br>On 28/08/2016 22:33, Ian Fritz wrote:<br>> Sounds familiar:<br>> http://ijfritz.byethost4.com/sy_cir4.htm<br>><br>><br>> On 8/28/2016 11:28 AM, Ben Bradley wrote:<br>>> I've designed but not yet built a triangle oscillator using a single<br>>> integrator and mux on the input. This uses two current outputs from<br>>> the exponential converter, one going to a current mirror, so there's<br>>> the same amount of current in both directions. The mux, driven by the<br>>> usual comparator with large hysteresis, switches the integrator input<br>>> between these two current sources. I'm not sure how a disconnected<br>>> current source will act when connected, but an extra switch can<br>>> connect the non-active current source to ground. This way the current<br>>> sources are always (except for switching times) connected to a virtual<br>>> or actual ground. Thinking another moment, a signal diode/1N4148<br>>> between each current source and ground, connected to forward conduct<br>>> when the mux switches off, may be a better solution.<br>>><br>>> Good symmetry of course depends on the current sources being as close<br>>> as possible.<br><br><br>_______________________________________________<br>Synth-diy mailing list<br>Synth-diy@dropmix.xs4all.nl<br>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy<br></font></body></html>