Christian Parker wrote: > Has anyone here ever tried to use the power supply from an old PC to power > their seismometer electronics? I have one laying around so I was going to > give this a try. The power supply outputs +12vdc and -12vdc from one of the > connectors that normally connects to the motherboard. The pinouts of this > connector are as follows: > > Pin Name Color Description > 1 PG Orange Power Good, +5 VDC when all voltages has stabilized. > 2 +5V Red +5 VDC (or n/c) > 3 +12V Yellow +12 VDC > 4 -12V Blue -12 VDC > 5 GND Black Ground > 6 GND Black Ground > > I'm wondering if this power is suitable for powering op amps? > > Christian Parker > Boulder, CO > cparker@............... > > Christian, I'am sure I'am stepping into this subject where I don't belong, but from my recollection from my brother, he has used these very supplys for various electronic experiments. Without further details, I would think that they might need additional power supply filters (capacitors) on the output. Usually one of the switching supply voltages is very limited on current capacity; so, one would have to watch that. Also "if" I recollect right.....(ahem), he stated that they are better than the regular power supplys for transient protection (spikes). J.B. Saunders surplus there in Boulder also has a wide variety of various types of power supplys there in Boulder; which might work. Of course the normal dual voltage supplys are somewhat rare compared to the switching supplys in quanity. One might consider buying 2 regular transformer DC supplys to join together to make the dual supply. Radio Shack also has these cheap single supplys available. The one remaining subject of power supplys is their regulation performance. Perhaps for amateur projects this can be fairly passed over, as the normal use involved doesn't normally cause problems where the sensor/s is coil/magnet and ampifier. I actually used one switching supply on my Hall seismometers for awhile, till it went kapoot. (I still saw transient spikes.... mainly from the house furnace motor...ha) Without knowing specifically what you are trying to do, its hard to recommend something. If you intend to lean toward a coil and magnet affair; I would suggest buying from Larry. His stuff works fine. The trouble with home brew is that one can usually end up spending more than buying commercially; and, end up with something less than the quality they would get if they had only just bought the stuff to begin with. Yes....electronics and computers drive me bugs....ha. Take care, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>