Front-panel LEDs to monitor +5,+12v power supply on IIe or IIgs

[buggie@aix06.unm.edu (Stephen E Buggie)]

FRONT-PANEL LEDs TO MONITOR THE +5V AND +12V POWER SUPPLY: IIE OR IIGS
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Anyone else out there who likes to use LEDs to monitor things? The main 
power for Apple IIs is from the +5v line (red wire) and +12v line (yellow 
wire.  The two negative voltages are for monitoring/comparison and they 
don't carry many amps.

Unknown to many Apple users, is that on EVERY APPLE MOTHERBOARD there are 
little voltage-fingers at the front-left corner, from which you can solder 
wires for extra accessories or gadgets. This applies to the IIe, IIc, IIc 
Plus, and IIgs. To get to those voltage-fingers, you must open the cover 
of the computer to expose the from edge of the motherboard. They are shiny 
long metal projections on the motherboard. ground is indicated, and all 
four of the voltages. Use your voltmeter, and identify the ground, +5v, 
and +12v fingers. Solder a thin insulated wire to each of those three 
fingers. Next, on the plastic front casing, drill small round holes for 
standard LED lamps. Attach a 100 ohm resistor to the red +5V LED, and a 
200 ohm resistor to the yellow +12v resistor. Insert the LEDs through 
their rfespective side-by-side holes. (On the IIe, I install the twin LEDs 
on the side/upper surface of the casing; on the IIgs box, I install the 
LEDs on the front of the removable upper box.  The LEDs are then connected 
to the wires from the voltage-fingers. That's it!  I've done similar 
modifications to external hard-drive boxes, so that the two main voltages 
can be monitored at a glance.    Steve Buggie


Steve Buggie                              |  Programmer / D.J.  |
Psychology Professor                      |   TROPICAL REGGAE   |
Univ. of New Mexico, Gallup               |three hours weekly on|
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