Andrew Morris decided the usual wireless volume controls don’t offer enough functionality, so he created the ultimate volume control that connects between a computer or MP3 player and an amplified speaker system.
Volume can be controlled up to 50 feet away and through walls. It doesn’t require line-of-sight, and you can set a default setting for your favorite level. You can also adjust multiple volume controls in the sound system. Morris is now setting the gadget loose on the world, hoping readers will try it out and give him feedback for improvements.
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One of my readers has designed a PCB (printed circuit board) for my gadget. He designed it to accomodate multiple configurations. That means what you do with the extra op-amp. For example, he uses it as a third channel for his high-end subwoofer. If you want a PCB, email me and I'll hook you up to him. I'm not making anything off of this project. I just want people to enjoy my gadget.
A reader wanted to use a different remote control system with greater range for outdoor use. I redesigned the pot controller chip to accomodate two momentary inputs (UP and DN). I also rewrote the remote receiver code to produce two momentary outputs, originally to test the pot controller. My email address is in the article. Please email me if you would like a copy of this code or preprogrammed chips.
The volume control has an auxiliary output for an optional audio switch to turn a subwoofer or audio system on and off with the incoming signal. If you are not going to use that, you can delete R2, R3, R8, D1 and D2. Add a wire in place of the diodes (between U4 pins 1 and 2).
No, It's not a Hammond enclosure. It's Radio Shack 270-1803. The link I sent you earlier has the part numbers and sources of parts not available at Allied. Since Allied sponsors this blog, they don't like people to mention the sources of parts they don't sell. That's why I sent you to my YouTube page.
It has to be an amplified speaker system connected to the TV (i.e. line-level or headphone-level signals). The volume control cannot control the speakers directly. If it is a line-level signal, delete the 100 ohm resistors at the input.
I built two remote volume controls and one of them is connected to a TV volume regulator, which has a line-level output. If the remote volume control is being connected to a headphone jack, the 100 ohm resistors are needed to allow the TV, or whatever, to sense the load and switch its internal speakers off. Most electronics nowadays use electronic means to detect a load on the headphone jack and switch off the built-in speakers. Gone are the days of having a mechanical switch in the headphone jack.
Thank you, yes, I have been thinking about asking you about programmed PICs. I am currently trying to source all the parts without paying too much shipping. If that is not too much hassle I may get a pickit2 and program it myself. If it's big hassle I may ask you for PICs to save some time. I'll let you know via email.
In our third annual contest, Design News and Allied Electronics are going to crown a winner in early 2016 for the best reader gadget submission this year, and once again, you, the readers, are the judges!
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