[rescue] 611s, 411 and ELC motherboards needing new homes (UK)
jkunz at unixag-kl.fh-kl.de
Wed Apr 23 03:27:44 CDT 2008
On Tue, 22 Apr 2008 10:34:57 -0400 (EDT)
der Mouse <mouse at Rodents.Montreal.QC.CA> wrote:
> > Current draw on +-12 V is only a few mA.
> Was that measurement on +12V done with the AUI Ethernet connected to a
> transceiver? I think AUI Ethernet needs +12V, but could be wrong.
Now that you say... It was without transceiver. Yes, AUI uses the +12 V
too. So you need to feed it more then a few mA if a transceiver is
used. But +12 V is no big problem. Many PSUs supply it in addition to
+5 V. (Think of SCSI boxes...) The -12 V is "unusual" and you can get
away with that inverter circuit in case of the ELC. (E.g. the MAX232 RS232 transceiver IC uses the same charge pump technic.)
> > Pins C and D on the 6 pin connector are in deed Csync. (One pin is
> > GND, the other is the usual TTL level sync.)
> Which is which?
I can't remember. It should be trivial to measure whith a Ohm-meter.
(I am to lazzy to dismount my ELC box now.)
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