TX/RX powered by 12 volts

[ponddude]

I was wondering if I modified the TX/RX with a heatsink or 2, could I power it with 12 volts, instead of the 6 that it normally gets from the wall wart?  I am not sure what the power draw is on the unit but I am sure it is low enough that the VR's wouldn't get over hot.

Can it or should it be done?

Greg

[tbone321]

You are talking about a significant voltage drop.  I would also suspect that it draws a bit more power than you think.

[ponddude]

You are talking about a significant voltage drop.  I would also suspect that it draws a bit more power than you think.

Well aware...just wondering if I can/should do it.

[jnealand]

I power mine when doing testing with 4 AA batteries.  Works great.

[ponddude]

Well I am going for a more of a permanent installation and want to stay away from batteries...but that certainly is an option I guess. 

What kind of battery life do you get?

[jnealand]

I did not use the batteries for a show, just for testing in my workshop and out in the yard, but I had them connected for hours at a time.  The only time I had to replace the batteries was after I forgot to disconnected them from the TX and did not get back to my workbench for a couple days.

[taybrynn]

I've about decide just to use the battery pack, but its a shame since I already have a 12v LiON battery pack which I am using for
the RGB modules and DMX controller.

Would something like this work?

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Or a mod like this?

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[D56VillageNut]

Greg,

I was wondering the same thing.  I'd see if someone else weighs in but that same type of VReg is used on the MR16 DC controller with a heat sink and the normal power supply for the MR16 controller is 12 volts.  I have an area where I have a 12v ATX PC power supply running a display element and would like to tap the 12v from it for the TX/RX instead of having a seperate wall wart for the TX/RX.

Thanks for posting the question.

Alan T

[ponddude]

Just an update here...

I ended up PM'ing RJ about this because no one really could knew an answer.  He said that he didn't think it would be an issue but never had tested it. 

I also never ended up testing it either....I ended up having a plug available in my shed, which is what I plugged the wall wart into.  Now my RX is working happily in my shed running my pond lights

Greg

[D56VillageNut]

Greg,

Thanks for the update and the feedback you got from RJ.
I pulled up the Mouser Direct BOM in the Wiki and from Mouser found the data sheet for the L7805ABV voltage regulator.
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In the electrical characteristics section (pg 10 for the L7805Axx) it shows the typical Input Voltage range can be 7.5 to 18 volts. 
I've got a spare TX/RX PCB so I may build one up and add a heat sink. 
My guess is that with a suitable heatsink the TX/RX should work fine on 12 volts.
I'll report back when I get a chance.

Alan T

[DaMenaCe]

Hey Alan,

Bro,i was wondering if you ever ended up testing this?? if so, would you mind posting results. My thoughts are to use a regular 9v Battery, That falls in the 7.5 to 18v range. Do you know/think that will work?? i would test it myself and just figure it out but, i still dont have the unit on hand..its on its way !! cant wait to assemble and Test it!!!

Dennis.

[D56VillageNut]

I've not built this yet but have a similar situation with my breadboard set-up. 

I built a power supply adapter from a kit that plugs right into the power and ground rails on my breadboard and it uses a 7805 Voltage Reg and the vendor says 7.5 to 12 volts for the input is OK.  I run it off a 1000ma 12 volt wallwart and have not had any problems. 

That being said, and I'm going out on a limb here, I believe that the TX/RX could be powered with 12 volts but I would look at adding a heatsink to the Vreg just to provide some additional cooling.

No guarantees and I'd be remiss not to point out that you do so at your own peril but I'm still planning to try this.

Alan T

[taybrynn]

I'm using a rechargeable 8.4v LiON battery pack (from ebay) and it works great.  No heat either and battery lasts forever.
But for me, I needed it to be portable.