Never mind my last post. The output would only swing from +10 to 0 volts, and bipolar would probably be more useful. See the attached image for a quick and easy schematic. The opamp type is not critical. Dave Bradley Principal Software Engineer Engineering Animation, Inc. daveb@... > -----Original Message----- > From: Dave Bradley [mailto:daveb@...] > Sent: Wednesday, April 12, 2000 3:27 PM > To: motm@egroups.com > Subject: RE: [motm] Power Supply and Joystick advice > > > There are a zillion resistor value pairs that you could use. The important > factor to get a specific voltage is the ratio between the two resistors. > Blah blah insert a bunch of irrelevant theory here.... > > Bottom line: > > Connect a 10K resistor to ground, and a 5.1K resistor to +15V of your MOTM > supply. Connect the free ends of the 2 resistors together, you'll > get about > 10V there. That's without trying to drive much of a load. To make the > circuit stable, connect the resistor junction to a voltage follower, which > is just any old opamp's positive input, with the negative input connected > directly to the output. Then the output of the opamp connects to one > joystick pot leg, the other pot leg goes to ground, and the pot > wiper is the > joystick output. > > Dave Bradley > Principal Software Engineer > Engineering Animation, Inc. > daveb@... > > > -----Original Message----- > > From: thomas white [mailto:djthomaswhite@...] > > Sent: Wednesday, April 12, 2000 1:50 PM > > To: motm@egroups.com > > Subject: Re: [motm] Power Supply and Joystick advice > > > > > > Thanks JB, > > > > I just want to get a rounded opinion on the max voltage I should > > use. I am > > pretty new to figuring out resistance since I come from a purely > > "A into B" > > kit background (Duh). So what values in the voltage divider would > > I need to > > scale down to 10v? Thanks, > > > > Thomas White > > > > >From: jwbarlow@... > > >Reply-To: motm@egroups.com > > >To: motm@egroups.com > > >Subject: Re: [motm] Power Supply and Joystick advice > > >Date: Wed, 12 Apr 2000 14:33:02 EDT > > > > > > > > >In a message dated 4/12/2000 9:44:23 AM, > > djthomaswhite@... writes: > > > > > > >On the joystick level, I am looking for the best way to drop > > the +15/-15v > > > >volts from the 900 PSU to +10/-10v or +5/-5v for joystick use. Which > > >voltage > > > >do you guys recommend? > > > > > >Doesn't the Klein schematic show something about a lower voltage > > (like 10V > > >maybe)? I say split the difference with a voltage divider (didn't I put > > >something about this in there too)? Take one 100K resistor and > > put one side > > >at 15V and on the other side place 1) a second 100K resistor, and 2) an > > >OUTPUT. Connect the other side of the second 100K resistor to > ground. The > > >OUTPUT should be about 7.5V. I know I put some stuff about scaling and > > >offsets in there, take a look at that too. > > > > > >I hope someone smarter than me will chime in and correct any > > errors I may > > >be > > >spreading -- but it should be OK for a FracRack! > > >JB > > > > ______________________________________________________ > > Get Your Private, Free Email at http://www.hotmail.com > > > > > > ------------------------------------------------------------------------ > > Motown & Soul Fanatics: Baby we need your ratings! > > New Music Site seeks song raters with a fine ear. > > Share what you know, and get compensated too. JABOOM > > http://click.egroups.com/1/3346/3/_/529958/_/955565397/ > > ------------------------------------------------------------------------ > > > > > > > ------------------------------------------------------------------------ > 1.6 Million Digital Images! > Download one Today from Corbis.com > http://click.egroups.com/1/3356/3/_/529958/_/955571368/ > ------------------------------------------------------------------------ > >
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RE: [motm] Power Supply and Joystick advice
2000-04-12 by Dave Bradley
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