Topic: KORG MR-1 External Power Source

[H₂O]

I am going to hook up my new MR-1 to an external battery.  Does anyone know the connector size?

Also does any one know how many mA's or Amp's it will pull on the 5volt power jack?  In the manual it says it draws 2.15 Watts (which I calc to 0.430 Amps at 5 Volts) but does this value take into count any additional current draw from charging the onboard battery?


I want to understand the battery life I can expect and to see what my total current draw against my battery will be.

Also the AC  PS included with the KORG is rated up to 2.4 Amps and I want to make sure the KORG doesn't pull this kind of current when connected to my battery.

I will be using a custom battery setup I have been using for years with a pair of adjustable linear volatge regulators (outputs two seperate regulated voltages from one high voltage battery).   The manufacturer of the battery I have suggests to keep the total current draw under 2 Amps.  I will  also be running a PSP2, which I am pretty sure only pulls between 300 - 500 mA's.

[H₂O]

The MR-1 Power connector looks like a EIAJ-02 (or Philmore 240 plug/TC240 cord/207 PC jack).  This is the same connector as used on the Sony TCD-D7/8, M1, and D100 - BUT NOT THE SAME VOLTAGE - SO DON'T TRY AND RUN YOUR MR-1 ON A D8 or M1 external battery.


An interesting article on the EIAJ connectors can be found here:
http://en.wikipedia.org/wiki/EIAJ_connector

Also I noticed the PS output is 5.2 V but the unit will run off 5.0 V.  Is there a set voltage where the battery charges (i.e. 5.2 V)?   So if youwhere to run at 5.0 V would it not charge the battery?

[H₂O]

Well all looks good for me. I was able to run the MR-1 at 5.08 Volts for 5 hours recording DSD on my battery setup and the battery only dropped about 25%. 

Based on my observations I would guess the current draw of under 0.5 Amps is pretty accurate.

Note the onboard battery was fully charged so it did not need to be recharged.

[H₂O]

Well now it doesn't look so good as the MR-1 died on me today on my setup.  I think the culpret is the power connector I am using as it is not an exact match to the Korg's (even though it is spec'd the same).

So off to Radio Shack tommorrow.

[mwz]

my power runner pr2300 has a plug that seems to fit just about right - pulled a nice 4061 > mma600 > mr1 last week.

[H₂O]

Thanks for the input mwz. +T

I was able to get this working with my battery finally and with the original connector cable I made many moons ago for my D8.  It appears my battery connector (the connector to the battery) was loose (idiot ).   My battery is now working and actually charging the unit.

One issue I did find through all this that when running the MR-1 and PSP-2 off the same power source a grounding issue may occur.  When I run both on the same battery and connect a from the mini of the PSP-2 to the 2 mini's of the MR-1 the PSP-2 will power on with out being turned on.   This will not happen if I run both off seperate external power sources.

So now I am resorting to using internal batteries in the PSP-2.  I have run it this way many times in the past but my PSP-2 battery slide is about as reliable as an AD1000 with a failing clock.  If the contacts aren't exactly positioned the PSP won't power on.

[gmm6797]

Ill admit I know next to nothing about the power stuff, so I follow these threads to a T to make sure I dont fry anything.

Any other suggestions other than the power runner pr2300 set to 5v?

I guess the USB port is just for data transfer and can not be used as a power source?

TIA

[bdasilva]

Yes.. the USB is only for data. When you're out of battery it will turn off, plugged in to the usb or not.

Power talk now... I'm going to put together a LM7805 regulator circuit. This will take my 9v battery and regulate it down to the 5vdc we need at an amp max.  I have measured the current draw and this should be enough. The JB3  did draw slightly more current and did have current "spikes" and the 7805 (with caps on the output and a good heatsink) worked fine.  I'll let you know.

[gmm6797]

I have a home made (from a friend, not by my hand) converter that takes the Wally World DVD battery down for a MicroTracker voltage (which I am told is the same as the JB3)... could this work with the MR1 if I change the connector on the end out from a USB (or better yet, add an additional output cable)?

[H₂O]

I use a LM431ACZ-ND VR which handles upto 3A and can be built to be adjustable.  I have a box with 2 (and very large heat sinks) so this allows me to hook up any voltage (a few volts higher then the voltage I am trying to match) and output 2 seperate voltages at any lower voltage using 2 pots (1 per VR).

http://www.alldatasheet.com/datasheet-pdf/pdf/112285/NSC/LM431ACZ.html

I have CAPs and protection diodes soldered in as well.

[Nick's Picks]

its draw is too heavy to use a 5v VR, that much I know. 
I also use a pr battery to great affect.

[H₂O]

its draw is too heavy to use a 5v VR, that much I know. 

What regulator did you try and use?

[Nick's Picks]

uuuhhh...., the wrong one?  I guess.
I can't recall the part, but its the common RS one I always use for other 5v devices.
1705?

[SmokinJoe]

I believe it's OK to hook up a couple of 7805's in parallel... so then you have twice the capacity.  In theory anyway.  I'm quite sure I read that somewhere... never tried it myself.

[bdasilva]

"I believe it's OK to hook up a couple of 7805's in parallel... so then you have twice the capacity.  In theory anyway.  I'm quite sure I read that somewhere... never tried it myself."

Google that and they all say "Bozo NoNo" 

Doing a test with a 7850 (to220 package) and IF the unit is charged when you start and IF you have a heatsink big enough it works fine. stays warm though.  Power in to the circuit draws 500ma (sitting on the table) and 700ma when it is recording This is all still within the 7805 specs.       I may build a LM2675-5 circuit and try that.

The test continues..