G. Hoffman
October 13th, 2008, 09:58 AM
For the last several years, I've been wanting to build myself a Leslie with DC motors and no power amp (DC motors because it gives me more control over the speed, and no power amp because then I can just run it off the power amp in my guitar amp, and since I want it for my guitar that just makes more sense to me). I can't actually afford to build anything right at the moment, but that just means I have lots of spare time to design things. So, I spent most of this weekend designing and prototyping the switching for the DC motors. The next thing to design is the actual motor control, but for that I'm just going to borrow an existing design to pulse the current to the motors, which is relatively easy.
http://farm4.static.flickr.com/3071/2937714932_4f7e637112.jpg (http://farm4.static.flickr.com/3071/2937714932_3c0f445513_o.jpg)
The analog decoding chip for that goes in the actual chassis needs ±6 volts, while all the foot switch electronics need +5 volts, so that's what's up with the three batteries. In the real thing, I'll get the ±6 volts from the 12v transformer I'm using for the motors, and I'll get the pedal power from my pedal board power supply. The two boards on the right with a single LED are the +6v and -6v power supplies, the two boards on the left are the foot switch electronics (a clever little latching setup I got from geofex.com (picture number 7) (http://www.geofex.com/Article_Folders/fxswitchr/fxswitchr.htm), and then an analog 8 to three priority encoder so I don't need to use a flippen' huge cable to get back to the cabinet.The other board is the decoding circuit for the chassis. It all seems to be working great, so now I just need to design some actual circuit boards for it.
This one is probably a LONG way out, but it's one of the more fun things to think about. The Leslie is the only thing I really wish I had in my guitar rig, so it's something I desperately want to build, but I just can't afford it right now. But I'll probably get around to it in a year or two.
Or five.
Or not.
But it sure would be cool.
Anyone want to pay me to build one of these for them?
Gabriel
http://farm4.static.flickr.com/3071/2937714932_4f7e637112.jpg (http://farm4.static.flickr.com/3071/2937714932_3c0f445513_o.jpg)
The analog decoding chip for that goes in the actual chassis needs ±6 volts, while all the foot switch electronics need +5 volts, so that's what's up with the three batteries. In the real thing, I'll get the ±6 volts from the 12v transformer I'm using for the motors, and I'll get the pedal power from my pedal board power supply. The two boards on the right with a single LED are the +6v and -6v power supplies, the two boards on the left are the foot switch electronics (a clever little latching setup I got from geofex.com (picture number 7) (http://www.geofex.com/Article_Folders/fxswitchr/fxswitchr.htm), and then an analog 8 to three priority encoder so I don't need to use a flippen' huge cable to get back to the cabinet.The other board is the decoding circuit for the chassis. It all seems to be working great, so now I just need to design some actual circuit boards for it.
This one is probably a LONG way out, but it's one of the more fun things to think about. The Leslie is the only thing I really wish I had in my guitar rig, so it's something I desperately want to build, but I just can't afford it right now. But I'll probably get around to it in a year or two.
Or five.
Or not.
But it sure would be cool.
Anyone want to pay me to build one of these for them?
Gabriel