Topic: jb3 external power II...

[dklein]

Just wanted to throw in that the JB3 is happy up to 5.6v so no need to worry about the 5.2
But I am curious, why bother with the LM317 variable supply and setting up the resistors to drive 5v - why not just use a 7805 that is fixed at 5.0 v

You get 1.5 A of regulated current for 75 cents!  Current capacity is all about heat sinking anyways.  With linear devices, the higher the voltage in, the more the regulator has to burn off, the better you have to heat sink it.  Because of that, you really don't want high input voltage - the regulator needs at least ~1.7v of 'headroom' for stable regulation.

So a 7.2v source is good here - it will start at 8.4v fully charged and by the time it drops to 7 (where the 'headroom' is running out) you are minutes away from the end.

Using higher voltage batteries means more heat.  There is no battery life advantage with higher voltage.

[mmmatt]

I believe Matt was erroneously referring to lee's regulated supply as a resistor box.  To (try to) clarify, the box Lee's building would take a wide range of incoming voltages and convert the incoming voltage down to 5.2 volts for the jb3. It does this by using a voltage regulator on an integrated circuit chip.

The car adaptor is designed to only be fed 12 volts.  Thus, unless it uitilizes a voltage regulator similar to that Lee's using, it would not properly reduce an incoming voltage of other than 12 volts down to the 5.2 needed by the jb3.  Lee's adaptor would allow folks to use non-12-volt batteries such as the 9.6v and 7.2v rc car packs and the ubiquitous wallmart 9v lithium ion battery to directly power their jb3s

Very interested in hearing how long a single wallmart 9v would power both a ua5 (with phantom on) and a jb3

this is where I'm confused.  I've ALWAYS used my hacked walmart adaptor with 9.6 RC batts.  It works flawlessly.  Start up, record, with internal batts, without... it doesn't matter.  Have you all been assuming you need 12v for a car adaptor? 

Matt

[dnsacks]

Until now

thanks for the clarification -- if Jason confirms that the 12 v adaptor will also work with a 9v lithium ion batt, I'm golden

[mmmatt]

Now if we could just throw a small regulator in line with the power cord, and reduce the size down to nothing more than a lump in a cord, I would be interested in changing, but a big advantage of the car adaptor is you can have a connection to reattach the cig lighter plug and charge/listen in the car.  I actually do that a lot.
Matt

[ChrisV]

Yep, I can also confirm my current setup of Wallmart car adapter w/ 9.6 V batteries works flawlessly(4.5 V setting).    But if something much smaller size wise that would still be nice to have too.

[dklein]

another confirmation that 9.6 v batteries work fine.  A while ago I wired up something that provides straight 9.6v to the UA-5 and runs a car adapter for the JB3.  i.e. One battery for both devices.  Someone asked me about this a while ago..I've got a picture here somewhere.

found it

[jdawg]

Cool, thanks for the pic.  That certainly clears up my confusion about hacking the creative car adapter. Meaning, I had bought a car adapter from radio shack that had an adjustable voltage switch (mounted within the cig lighter plug) not as a separate box in line.

Anyway, just ran the JB3 using the lm317 circuit for 6.5 hours from the 9.6v rc batt.  Just passing along the results. 

The only reason I'm trying this circuit is because it looked like a fun little project, otherwise, the "creative" car adapter seems like an easy route, but I also wanted to use hardware that I already had on hand. Now if I could just learn how to transfer this circuit from the breadboard to a chip and solder everything together, I'd be golden.

-john

[leegeddy]

Just wanted to throw in that the JB3 is happy up to 5.6v so no need to worry about the 5.2
But I am curious, why bother with the LM317 variable supply and setting up the resistors to drive 5v - why not just use a 7805 that is fixed at 5.0 v

You get 1.5 A of regulated current for 75 cents!  Current capacity is all about heat sinking anyways.  With linear devices, the higher the voltage in, the more the regulator has to burn off, the better you have to heat sink it.  Because of that, you really don't want high input voltage - the regulator needs at least ~1.7v of 'headroom' for stable regulation.

So a 7.2v source is good here - it will start at 8.4v fully charged and by the time it drops to 7 (where the 'headroom' is running out) you are minutes away from the end.

Using higher voltage batteries means more heat.  There is no battery life advantage with higher voltage.

>>Just wanted to throw in that the JB3 is happy up to 5.6v so no need to worry about the 5.2

thanks for this info. i fully assumed that a jb3 will operate safely at 5.2v.

>>But I am curious, why bother with the LM317 variable supply and setting up the resistors to drive 5v - why not just use a 7805 that is fixed at 5.0 v

in the case for the jb3, a VR circuit with a 7805 will work just as well. however, i'm looking at this from an overall power supply solution. as we all know that different equipments require different operating voltages (ie. jb3=4.5-5v, d7/d8=6v, d100/m1=4.5-6v). by designing a robust VR circuit with the LM317, i can achieve the desired Vout by simply manipulating resistors.  i don't have to go and get 7805 for 5v, 7806 for 6v, etc.

>>You get 1.5 A of regulated current for 75 cents!

LM317 packages aren't too expensive either AND much more versatile to suit a specific Vout need.

hope you can see where i'm coming from.

marc

[Sanjay]

I tried earlier in the summer building a voltage regulator with minimal success, the spikes of the HD spin would lock it up when I tried using all my different circuits, over thanksgiving when i go home i'll dig out hte circuit diagrams and throw em up here to see what people can make out of it.  I had used a 4 D sled and through a series of resistors ect lowered it to a voltage where the JB3 would record but after 2 minutes it would lock up.  A few times I smoked the components, that was fun. 

[Chris K]

google-ing for 5v power, i came upon a surveillance camera company that has a 5V 2000mAh lithium battery pack with charger for a wireless spy cam. wonder if it will work with the jb3

http://www.taisun.com/ts-505vinfo.htm

tiger direct has something similar a little cheaper, and 3600 mAh

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=318871&sku=D135-1032

[Ed.]

in the "Nomad Batteries are getting rare" thread someone post this link and said that this works with the nomad

http://www.pwrplant.com/cd.html

[krebsy]

Getting back to hacked car adapters.  I just got an "official" Creative car power adapter.  Wiring it up to a 9.6v RC batt puts out about 3.5v, not enough to operate the JB3.  The input voltage on the adaptor lump is listed as 12-24v, so I guess that's why I'm not getting sufficient voltage on the JB3 end.

Anybody out there using the Creative car adapter successfuly?  Am I missing something?  For those succesfully using the ballzmart car adapters, do they list input voltage, and what's the part number on that bad boy?.  I'm determined to run a UA-5/JB3 combo from one type of battery (non SLA that is)!!  Thanks!

[mmmatt]

I run the wally world adapto from 9.6 v rc batts with absolutly no problems... I don't have a part number but it was the bigger of the two available (2000 mah I think)

Matt

[F.O.Bean]

I run the wally world adapto from 9.6 v rc batts with absolutly no problems... I don't have a part number but it was the bigger of the two available (2000 mah I think)

Matt

i have a few of those

[leegeddy]

before i packed up my things for the cross country move, i got the voltage regulator circuit to output 4.97V with an input of 7-24volts.  i should have the first prototype done for Bean to test out in the field. 

marc