JeffD wrote

QuoteThis is too simple. you guys are thinking too hard.  
Keep it simple.

For you, me, and a few others it is.  
Between my written lines are your thoughts exactly.

The gadgets that take external power are no sweat. Firewire, blowtorch, nuclear fusion, etc.  :lol:

It is the Motocomm box that is designed to be portable and audio flexible, not power flexible, that is the center of his needs.

Conan, does the battery door cover both batteries or just one. If both, we could try to find a donor cover and build the battery eliminator contacts into the door. This way no warranty issue comes into play and if you decide to sell it off, no hacking involved for the new owner to see.

You guys just would not believe the stuff I see with missing battery covers. Somewhere on this planet, or another dimension, is a landscape covered in battery covers.   Hmmm...that would make an interesting piece of art or CGI art.  

You're right on target Starwalt.  I upgrade, fix and build PC's but i am a complete dunce when it comes to a soldering iron.

Here's the battery door:



and



I'm not worried about resale, so I could send you the battery door if you wanted to be nice and hook me up.

Well what abou this.  

2 dowl rods the same size as a AA battery.   Wire the 3v needed on the dowls.  Push the Dowl rods into the battery tray to make the connections.   Then you'd just have the 2 wires coming out of the battery tray, and I hope it can bend enough for 2 ~20gauge wires.  If not, a small hole drilled to fit the wires.

Pictures! Hurray!  

I remember some configurable electric cars that had dummy AA cells that acted as jumpers for the battery holder in the car. Dowels with sufficient contact would work as well.

Or, for that matter, an appropriate size perf board or fiberglass board with the battery contacts required. Usually one end of the battery box is just a jumper to series the batteries. The other end of the board would have the needed battery connections. A wire soldered and attached to the board would exit to the appropriate power source.

This way any connector would do. I like the coaxial DC connectors over uses of audio connectors (some designs actually allow a momentary short of the power supply prior to complete insertion   )  In this senario, Conan simply drops the board into his compartment, routes the cable and snaps on his cover.

Since Conan isn't going to worry about some modifications, a simple notch cut in the edge of the cover would do for the cable to exit and still maintain the integrity of the cover.

I've got to travel today for work and have my math class tonight. Keep the faith Conan. A solution is brewing. I will dig around in one of my many storage boxes. Between Jared and I, this will get done.

Is this what product marketing committes have to deal with?

Ok Conan, here's the idea so far:


Wire carrying the 12VDC from another connector on the "junction/conversion box" housing Firewire and USB connectors would be on this module. The module would convert the 12 to 3VDC. The module would snap into the ABoss using built in connectors.

I call this a 1 3/4 AA module because the spring common to the dummy positive end would be in the way of installing the module. Just take the module and insert it double end first into the correct end of the ABoss. If installed in the incorrect end, you short the module out. Maybe I will incorporate an LED to let you know if installed correctly.

Most of the low voltage regulators have short circuit protection. I plan to build the prototype circuit and cast it to shape in clear resin. The LED would be embedded to allow you to see its cool glow.  

Wow, talk about exceeding expectations!

you rock!

I've been busy today catching up on math homework and spending some time with the Audioboss adapter. I had several LM317T in my regulator drawer. Here's the result of testing the output with a load. The load is a horrible electronic audio toy someone gave one of the kids 15 years ago. It plays synthesized versions of children's songs and flashes an LED. The best thing is it uses 3 volts. The meter is displaying the output voltage while the toy is running. No load was 2.9VDC.



I measured the load current both DC and AC. It never went above 350 milliamps and the speaker has no volume control. It blasts horrible partially out of tune electronic music as long a the button is pressed.

My only concern was the warmth of the LM317. Although not horribly hot, it will warm depending on the load placed on it and the differential it must regulate. Some heatsink integrated into the 1 3/4 AA module may be needed. The source voltage was over 13 VDC.

I will be in Cleveland for several days this week and probably won't get to this until sometime next week. GStwin will be accessed though.

Yeah  I had the same problem with one of my projects in school.  The LM317 can handle 1.5A out  so it can drive just about anything you throw at it.  However regulating more than 10v can get it pretty warm.

An aside.  I was regulating 34v down to 12 and it wouldn't push above .75A, and it was heating up fast.

Lets see how much power you were cooking with.
13v supply
3v out
.350A

so you were dropping 10v*0.35 so 3.5 watts.

Using the equations off of  www.digikey.com  the LM317 TO-220 can handle 5 watts.  So you are below that.   Why not use a 3v zener off of the 5 v supply? it will lower the power consumption and also reduce parts.  Of course this would limit the audioboss current but if we knew that it would be easier.

Quote from: JeffD..Why not use a 3v zener off of the 5 v supply? it will lower the power consumption and also reduce parts...

I had considered that as the next alternative if the 317 method proved uncooperative.

After tweaking the R1,R2 combination to give just over 3 volts, I left the entire setup running on my bench with an old GS battery while I went to Cleveland for 4 days. With the noisemaker as the load in quiet mode, the output is still steady after 4 days.

Next will be making a constant 350 mA load and see if it melts down with no extra heatsink. If it dies, I will integrate a heatsink into the drop in module.