On 4/16/2012 1:30 PM, Stephen Dubovsky wrote: >> Expense. A USB cable is cheap and that eliminates the DC-DC converter >> cost since the power is coming from the proper side of the optos. >> >> >> > But w/ cheap comes low reliability? The USB can be power up/down by the > host. A USB fault will turn the power off. I don't know if a fault on > another channel turns them all off or not. Would be bad if you plugged a > bad usb key in and crashed the running machine. I know w/ my phone plugged > into my work machine to charge (admittedly win7), the charging restarts > once in a while. Not sure if its the phone (android) or something going on > w/ the usb port. > > Little dc/dc converters or wall-warts power supplies are cheap too;) > Probably better just to grab 5V directly off the PCs power supply than to > use USB. Wire up a cable to plug into a spare floppy/CDR power connector. > > SMD >
>>But w/ cheap comes low reliability? If you believe that to be true, what are you doing using LinuxCNC? ;-) You should not put a USB stick into a running machine. Bad things may happen. Both Windows (definitely) and Linux (sometimes) has a problem with USB insertions and removals. Sometimes simple is the best solution. >>Wire up a cable to plug into a spare floppy/CDR power connector. You are assuming the customer is qualified to open the PC case... :-) The G540 is a very low cost product. Marris is going to do some serious nail biting before he adds any cost to his product. Dave ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
