Topic: jb3 external power II...

[hexyjones]

Dumb question of the week...

What da heck does SLA stand for?

[poorlyconditioned]

Dumb question of the week...

What da heck does SLA stand for?

Not a dumb question.  We all have geek terminology.  Sealed lead acid battery.  (I think...)

  Richard

[hexyjones]

I can use one of these and one of the Creative car adapters, correct?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73335&item=5751577596&rd=1#ebayphotohosting

[mmmatt]

Dumb question of the week...

What da heck does SLA stand for?

Not a dumb question.  We all have geek terminology.  Sealed lead acid battery.  (I think...)

  Richard

well... actually that would be SLAB!  sealed lead acid

I can use one of these and one of the Creative car adapters, correct?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73335&item=5751577596&rd=1#ebayphotohosting

yes, but you can use any car adaptor that does 4.5-5v and any battery that is 7v or higher.  Ni-MH (nickle metal hydride) RC batts, sla's, and lithium rechargeables all work great

Matt

**edit**  sorry... I just followed that link.  that battery is a NiCad (Nickle Cadmium) (sp?) and thoes will form a memory... that means that you have to discharge it and charge it all the way up each time.  Ni-MH, and Lithium are the best in this regard.  SLA is like your car battery, and should never be fully discharged.  SLA is heaviest, lithium is lightest... take your pick.  I personally like Mi-MH becuause they are easy to maintain, reasonably light, and very cheap.   Try here  http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=474

[dgodwin]

I can use one of these and one of the Creative car adapters, correct?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73335&item=5751577596&rd=1#ebayphotohosting

I actually have a couple similar items I bought back in July at woot.com  You can see some information about them, as well as comments in the thread below.   
http://forum.woot.com/forum/viewtopic.php?t=22  and here:  http://www.synmicro.com/itemDetail.asp?z=AC20720C

Basically, the unit outputs 12v, and inside contains 27 alkaline AA batteries.  I've used them camping a few times to power small lights, but I'm considering using one for my JB3 that's in the mail.  Has anyone used them before, or have any comments on why I shouldn't use it?  My main concern (other than will it work at all) is how long of a recording time should I expect with this unit.  Thanks in advance. 

[fozzy]

I can use one of these and one of the Creative car adapters, correct?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73335&item=5751577596&rd=1#ebayphotohosting

I actually have a couple similar items I bought back in July at woot.com  You can see some information about them, as well as comments in the thread below.   
http://forum.woot.com/forum/viewtopic.php?t=22  and here:  http://www.synmicro.com/itemDetail.asp?z=AC20720C

Basically, the unit outputs 12v, and inside contains 27 alkaline AA batteries.  I've used them camping a few times to power small lights, but I'm considering using one for my JB3 that's in the mail.  Has anyone used them before, or have any comments on why I shouldn't use it?  My main concern (other than will it work at all) is how long of a recording time should I expect with this unit.  Thanks in advance. 

The important info is the mAH.  for 12v you would need 8 AA bats @ 1.5v or 10 @ 1.2v for rechargables.  The math doesn't work for 27 AA batts.

You could probably do much better w/ the Wal-mart Li-Ion or even a SLA

[John R]

jimmc, thanks for running that time test.  good to know there is an "all (festival)day" power source.  just what i've been waiting to hear.  +T

[mmmatt]

I can use one of these and one of the Creative car adapters, correct?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73335&item=5751577596&rd=1#ebayphotohosting

I actually have a couple similar items I bought back in July at woot.com  You can see some information about them, as well as comments in the thread below.   
http://forum.woot.com/forum/viewtopic.php?t=22  and here:  http://www.synmicro.com/itemDetail.asp?z=AC20720C

Basically, the unit outputs 12v, and inside contains 27 alkaline AA batteries.  I've used them camping a few times to power small lights, but I'm considering using one for my JB3 that's in the mail.  Has anyone used them before, or have any comments on why I shouldn't use it?  My main concern (other than will it work at all) is how long of a recording time should I expect with this unit.  Thanks in advance. 

The important info is the mAH.  for 12v you would need 8 AA bats @ 1.5v or 10 @ 1.2v for rechargables.  The math doesn't work for 27 AA batts.

You could probably do much better w/ the Wal-mart Li-Ion or even a SLA

yeah, that is true and keep this in mind also: battery size and weight is determined by two things... voltage and amperage (and the type of battery also).  Add more of either and the weight goes up.  The usable charge of the battery is only determined by the amperage after you reach the minimum for the converter to work... everything else just gets burned off.  So unless you have a reason to go 12 volt, you are just making your bag heavier, and battey power is wasted in generating voltage that will just get burned off in the convertor anyways.  If you are going to use that many batteries, you may as well use them right.  When you connect a battery group of same voltage batteries in series (daisy chain pos to neg to pos to neg etc) you increase the voltage, and when you connect in paralel (pos to pos to pos and neg to neg to neg etc) you increase the amperage.  It may be too early for me to try to make sense here, but that is how it works.  Don't knock yourself out trying to get to 12 volts just because the car adaptor is "meant" for that.  Besides what a pain in the ass it would be to charge that many AA batts... with the RC batts, or the Lion you just plug in once and walk away.

Matt

[phanophish]

So one quick question.  What input voltage does the UA-5 like.  I'm going to buil a box like Mark did and would like to make it run everything I have.  If I can run the JB3, D8 & Dmic20 off the 5.2 V circuit then I'd only need a second for the UA-5 so what should it's output be?

[fozzy]

So one quick question.  What input voltage does the UA-5 like.  I'm going to buil a box like Mark did and would like to make it run everything I have.  If I can run the JB3, D8 & Dmic20 off the 5.2 V circuit then I'd only need a second for the UA-5 so what should it's output be?

I'd worry about the load on your 5v.  dunno what the draw of the dmic and d8 are but the jb3 can spike up to 1amp.  I run a dedicated 1.5A circuit for my JB3.

UA5 is reliable from 7.2-12v. 

[Brian Skalinder]

What input voltage does the UA-5 like.

Check the UA5 FAQ in the Archival Info forum.

[phanophish]

That answers my question.  I'm not going to run them all at once on a single circuit, just be able to run my JB3, D8 or DMIC-20 off the same power supply with different output cords.  Make sense?  Maybe build 3 or 4 circuits in to a single box, but then I'd worry about heat. I'm trying to get together a good festival rig for this summer. 

[phanophish]

I'm thinking of getting some custom made PCB boards made that would support this circuit.  One place I checked out would make a board that is about 3.5 x 2 and would be able to support up to 3 of the LM317 based circuits so you could have 3 outputs each with a different voltage off a single input and be able to change the output voltage just by swapping out 2 resistors.  My only real concern in heat.  While there would be room for heat sinks in the box, there would not be any airflow.  Just how hot do these things get?  Obviously as the quantity goes up the price goes down so I'm also curious how many people would be intreseted in buying a PCB board if I had them made.  I've attached a quick CAD drawing of the circuit I'm looking at.  Any comments?

FYI it is a 2 layer board the green is on the bottom layer the red is on the top layer and where the components go through the board it makes the electrical connections

[tms]

To figure the heat you'll need to sink, calculate the efficiency of the LM317 at the voltage and amperage you want to run at.  I suspect you'll need a decent heat sink on each one, and air free to move thru your enclosure.

Basically these things take the extra voltage and dump it to heat.  So if you're running 10 volts into it and getting .5A at 5V out you have to dump the other 5V to heat.  So that's 2.5 watts. The closer you supply to the output the less waste.

They can get very hot.  A good rule of thumb (literally) is that if you can hold your finger on it, it's ok.  If you yank it away in pain, it's too hot and you are overloading the chip, and it will die soon.


My question is, what happens when the battery dies?  Do you lose the show you're recording on your JB3?   Does it lock up if all of a sudden you start feeding less than 5V into the DC-in connector?  The JB3 is not very robust when it comes to its DC-in !  So it's important to use a big battery for the power supply and hopefully monitor its voltage so the JB3 doesn't crash in the middle of a show.

I'm thinking of getting some custom made PCB boards made that would support this circuit.  One place I checked out would make a board that is about 3.5 x 2 and would be able to support up to 3 of the LM317 based circuits so you could have 3 outputs each with a different voltage off a single input and be able to change the output voltage just by swapping out 2 resistors.  My only real concern in heat.  While there would be room for heat sinks in the box, there would not be any airflow.  Just how hot do these things get?  Obviously as the quantity goes up the price goes down so I'm also curious how many people would be intreseted in buying a PCB board if I had them made.  I've attached a quick CAD drawing of the circuit I'm looking at.  Any comments?

FYI it is a 2 layer board the green is on the bottom layer the red is on the top layer and where the components go through the board it makes the electrical connections

[phanophish]

I've got everything coming to do a mock up and will be testing without any air flow initally, just heat sinks.  If all goes well, then I will explore getting the PCBs made up.  I'll let everyone know how it goes.  I know a few people have made boxes based on the same circuit, but have not heard anything related to thermal issues, especially with multiple circuits.  The LM317 stuff I have seen indicates the chip does have overheat protection so it would shutdown before damaging the chip, but you would loose power suddeny if the overheat protection kicks in.  Anyone know how to make a circuit that would indicate input voltage through some LEDs?  We could build that in so you can monitor input voltage level and know when you are getting low.  I wouldn't think it would be too hard, but I'm not a electronics wiz.