Topic: JB3 Remote Power...it cuts out?

[Ian]

Ok, well, my remote power works and all, using my eco-charge EC-90, but I have to boot up with batteries, and leave a fully charged one in, so for the intense current draws it can work. Like, when it tries to boot up, it can't, and just continues to try, and sometimes it freezes the JB3. My cell phone charger was only rated at 1A, and the JB3 pulls like 1.5A at most, so I'm guessing that's the problem. What are some ways around this? Lemme know! Peace, -Ian

[Brian Skalinder]

I'm not clear on exactly how you're powering your JB3.  You're using the EC-90 as a power source?  How are you dropping the voltage to the 5v that the JB3 requires?  How does your cell phone charget fit into the picture?

[Ian]

Hold on, I'll post pictures.

[Ian]

Here's the whole setup plugged in. Note: Dead battery. Otherwise the LED would be red (on) and the JB3 would say it's plugged in.



Here's the "cell phone charger" part of it.



And here's the plug I made for the EC-90, as pin 1 is ground, and pin 4 is hot. It's just a modified XLR, but I only needed two prongs so it works.




I had it in this configuration for well over 15 hours, constantly running. The problem I'm facing, is that I think the cell phone charger part has a max output of 1A, thus, when the JB3 tries to draw like 1.5A, it can't and if the internal battery isn't in, it shuts down. The easy solution is to keep a fully charged internal battery in it, but I don't much like that. I want to electronically solve it. Thanks, -Ian

[Brian Skalinder]

You could replace the cell phone bits with a 7805 voltage regulator + heat sink.  Others have proposed slightly more elaborate setups that are more efficient, but that'll definitely do the trick.

[Ian]

Please see my other post. I have two 7805 regulators, and neither seems to work. Help?

[leegeddy]

is the 7905 chip getting hot? that cellphone dc charger is not designed to pass large amounts of current. the un-heatsinked ic may be shutting down.



...and please use some kind of electrical tape to protect live circuits while you're working. there's nothing worse than seeing sparks from shorts and it's not good for your battery.

marc

[JackoRoses]

for as much time and effort you have gallantly put into this project,
you could of went to wallyworld/ratshack and picked up one of them cig adapters
that will allow you to change voltage down to 1.2 or something.

[F.O.Bean]

for as much time and effort you have gallantly put into this project,
you could of went to wallyworld/ratshack and picked up one of them cig adapters
that will allow you to change voltage down to 1.2 or something.

thats right, after all, thats what they were made to do, step down voltage from a 12v power supply

[Ian]

Yes, but neither of the Radio Shacks I went to had something that would work, nor did Wallyworld. So I made this get up.

[JackoRoses]

Yes, but neither of the Radio Shacks I went to had something that would work, nor did Wallyworld. So I made this get up.

man that is crazy what luck.
there is also the VR box if you can't get this running or check ebay.
Not much eletric help to offer but a T instead for the effort

[tms]

Ok, well, my remote power works and all, using my eco-charge EC-90, but I have to boot up with batteries, and leave a fully charged one in, so for the intense current draws it can work. Like, when it tries to boot up, it can't, and just continues to try, and sometimes it freezes the JB3. My cell phone charger was only rated at 1A, and the JB3 pulls like 1.5A at most, so I'm guessing that's the problem. What are some ways around this? Lemme know! Peace, -Ian

I have the same problem with my RatShack and WallyWorld cig lighter adapters which put out 4.5V instead of 5.0 volts.  It freezes sporadically, doesn't charge the internal battery completely.  Only it sounds like your cell phone charger isn't able to put out the amps.   Here's what I found about JB3 power use a few weeks back:

Yesterday I measured the current consumed by my JB3 while recording line-in using an external power source.  My external power source is a $2 7805 5 volt regulator from RS.  To use it I pull the internal battery so that the JB3 doesn't try to charge it with the external power.  That would be a big waste of the external battery, plus it adds a whole bunch of hiss, clicks and beeps to the line-in recording. 

Here are the results:

Boot-up and harddrive 'punches' : 750 mA spikes
Toggling thru the menus (back light on): 120 mA
At rest, no back light on: 70 mA
Here's the important one, Recording: 230 mA with an occasional spike to 750 mA when the HD punches, I'm calling it 300mA average.

The 7805 chip (and Leegeddy's variable volt box) consumes the exact same amperage as is sent to the powered devices.  The excess wattage (Vin - 5 V)*amps goes to heat.  In my case, it's a 12V supply, so (12-5 V)*0.3A = 2.1 watts of waste heat.  The chip is mounted to a scrap piece of aluminum and doesn't even seem warm to the touch.

I also use a pre-amp which uses 30mA at 12V.   Based on this, my 12 Ahr 12V SLA battery should last (12,000 mAhr)/(330 mA) = 36 hours.

Hopefully this will be useful for someone planning to use or build an external power supply for festivals, etc.

Cheers!
Todd in Buffalo

So build yourself a LM7805 chip based power supply.  It is literally 3 solder connections, will give you very efficient conversion of voltage, plenty of mA, and is battery quality (no noise) power.

Good luck, and please PM me for any help I can offer,
Todd in Buffalo