From Ric_Miller@MBnet.MB.CA Thu Sep 1 11:28:39 1994 Date: Sun, 10 Jul 1994 16:45:41 -0500 (CDT) From: Ric Miller To: Analogue Heaven Subject: Simple LFO... in ASCII (Heh heh) > From: Mark Pulver > Subject: Simple LFO... > > I'm looking to build a couple of simple LFOs and figure that there's > gotta be something easier than using (wasting?) a SSM chip to do it. > > All I need is triangle out by the way.... Max freq about 30hz.... No > need for CV control or anything else. Can I get this with a simple opamp > circuit? > > Thanks! No problem (in advance). Always glad to help. :) |---------------------------------------------| | |----||-| | | | |\ C | |\ | |---/\/\/----+--|-\ | |---|-\ | R1 | |-+--/\/\/--| GND | |--+-----o Square |--|+/ | R2 |--+-----|+/ | | |/ | | |/ | GND | | | o |--/\/\/----| Triangle R3 Legend: ------ + = Circuit connection | = Vertical trace - = Horizontal trace GND = Ground connection C = 2.2MF (or 0.01 to 2.2MF dependant on frequency requirements) R1 = 100K pot R2 and R3 = 10K to 100K, with R3 at least 1.5 times the size of R2 (IE: If R2 is a 22K resistor, then R3 can be a 47K) The op amps can be any op amps, for your stated frequency requirements. Hope this does the job for you. Ric