Guest Anonymous Posted January 10, 2004 Report Share Posted January 10, 2004 Recording really seems to eat the battery on my MZ-N505. I usually record discs using NetMD; I just transfer tracks with Sonic Stage. Since I've got the USB cable plugged in anyway, why can't I get 3.0 volt power that way too? Sure, I can use the AC adapter, but sometimes I've got my 505 at work and I forgot to bring the adapter with me. Is anyone out there clever enough to figure out a way to get 3 volts off a USB port? I'm looking at rigging a cable using something like one of these: http://www.powerstream.com/Produz11.htm http://www.galaxypwr.com/Gemini.htm Quote Link to comment Share on other sites More sharing options...
Daijoubu Posted January 10, 2004 Report Share Posted January 10, 2004 If anyone is brave enough, try to directly solder some wires inside your unit to power up the unit via the USB connector Would be especialy handy for NE410 users (no AC input..) I'm gonna take a look Pin 1: +5 Pin 5: GND Pin 1: +5 Pin 4: GND We could just use a simple resistor, power is pretty regulated in the PC, no need to worry about that :? I think... According to the service manual, the N505 needs: Servo on: Playback: 160mA Recording: 180mA FF/RW: 170mA Pause: 100mA Servo off: Playback: 20mA Pause: 20mA Quote Link to comment Share on other sites More sharing options...
highlandsun Posted January 10, 2004 Report Share Posted January 10, 2004 Yes, the USB specs require a port to provide exactly +5V at a maximum of 500mA to any port. If you know exactly how much current you're drawing, you can find the right resistor value. But since V=IR, if the current draw varies (depending on the MD operation in progress) then so will the voltage. You might do better with a 2V zener diode to drop the voltage down, independent of the current. Quote Link to comment Share on other sites More sharing options...
Daijoubu Posted January 10, 2004 Report Share Posted January 10, 2004 This is odd, the 5+ IS connected to the IC604 and a transistor to detect whenever or not a cable is pluged... The units doesn't use it though.. I beleive that the easieest way would be making a special usb cable with a DC out jack, the unit cannot turn off the batt itself unless something is plugged in (A dumy plug could work too, or some more soldering? ...) Quote Link to comment Share on other sites More sharing options...
highlandsun Posted January 10, 2004 Report Share Posted January 10, 2004 I'm glad you raised this topic though. It always annoyed me that my MZ-N10 cradle needed both the +6V DC input and the USB connection. I really don't understand why they're drawing +6V, when the internal battery is only a 3.6V LiIon, and the external battery is only a 1.2-1.5V AA cell. I've also wondered what kind of step-up circuitry is in the external pack. If I inserted a 3.6V rechargable LiIon AA cell, would it burn out? (Probably.) Time to go looking for service manuals..... Quote Link to comment Share on other sites More sharing options...
Daijoubu Posted January 10, 2004 Report Share Posted January 10, 2004 mmm you could power up the unit but not really charge the batt due to the low wattage of the usb output, you should know about that o.o And i don't think there's anything in the batt pack :shock: Quote Link to comment Share on other sites More sharing options...
highlandsun Posted January 10, 2004 Report Share Posted January 10, 2004 I tried the 3.6V LiIon AA - when I pushed play, the display flashed "Hi DC In" so I took it out again. There's definitely a step-up circuit in the pack! Quote Link to comment Share on other sites More sharing options...
bertrik Posted January 10, 2004 Report Share Posted January 10, 2004 USB devices advertise their maximum current draw to the PC. A NetMD minidisc player probably indicates just a few mA just for communication (I can find out the exact value by looking at the USB config data). When the device (MD player) draws more current than indicated, the USB host (PC) may decide to limit the current to the device or even cut the power. I've heard / read somewhere that desktop PC are not so critical with this mechanism, but laptops are. So I think it may not even be possible to draw much current from the USB port. (edit: just noticed that under Linux, usbview shows that my MZ-N510 can draw a maximum of 100 mA) Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 12, 2004 Report Share Posted January 12, 2004 Yes, I was thinking making a custom USB cable and taking power off pins 1 and 4. I found this voltage regulator, which looks like my best bet so far: http://eu.st.com/stonline/books/pdf/docs/2572.pdf They've got a fixed 3.0 volt version. Now all I need to do is find a place where I can buy one or two for a reasonable price. It would also be nice to find some kind of USB cable with a "pass-though" built into the end. Otherwise, I'll need to use a second USB port (first port is connected to the 505's USB cable). I guess I could also take the 5 volt off the PS2 port, since I don't have anything connected to it... Quote Link to comment Share on other sites More sharing options...
highlandsun Posted January 12, 2004 Report Share Posted January 12, 2004 A voltage regulator may be overkill here; they're generally used to drop an unregulated input and produce a regulated output. Here you have a fully regulated 5V input. A single 3V zener diode, or 3 silicon rectifier diodes in series, will be enough. I always choose a simpler component when possible, for greater reliability... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 18, 2004 Report Share Posted January 18, 2004 the new hi-md now draws power from the pc while its plugged in... HORRAY! Quote Link to comment Share on other sites More sharing options...
madbeaver Posted February 5, 2004 Report Share Posted February 5, 2004 Hi Is there anybody that knows where to find the full specsheet for the NE410 model? I'm loking a way to modifiy my player/USBcable to draw current from the PC. to be able to do it I'll need the complete circuitry sheets to find a way to do that. I found this site that allows to take the usb port and supply 5 and 3.3V http://www.audioscientific.com/51_Supply_d...m_USB_port_.jpg All I need now is the NE410 circuits sheets Thanks a lot Quote Link to comment Share on other sites More sharing options...
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