While conducting assorted Lifter experiments, I normally would choose between either the Glassman High Voltage EH Series, or the less finicky Information Unlimited GRA3 Series high voltage DC power supply. However, as such things sometimes happen, every so often an electrical experiment can go terribly wrong. In one such case, while rerunning a replication of T.T. Brown's Electrokinetic Apparatus, extended the gap between emitter wire and leading edge of the Flying Wing Lifter to about 7cm. Upon turning up the high voltage, immediately experienced a thunderous short circuit, and bright sparks flashing within the plastic spinner cap at the top of the rotor. Although I shut down the power supply immediately, considerable damage had already been done. In a quick puff of blue smoke, my once reliable GRA3 was dead... emitting that fried stink of an unwelcome short circuit.

Thus the first step was to open up the GRA3 unit, and inspect the internal guts of this old power supply for damage. Sure enough, once the protective covers were removed, found most of the power supply more or less undamaged, while a offending pair of resistors were quickly located. It was immediately obvious these two were totally fired to a crisp, in fact burning right through the base of the circuit board when they blew. Reviewing the schematic diagram thoughtfully provided by the manufacturer, I identified these two parts as 220ohm - 1/2watt, and 47Kohm 1watt resistors. 

Visiting the local Radio Shack, encountered a sales person with limited knowledge regarding actual electronic parts, skilled only in promoting cell phone plans and selling other electric whirligigs. Receiving little genuine assistance, was told the exact replacement parts I needed were not available. Specifically, there were no 47Kohm 1watt resistors found in stock, and beyond that... only a blank stare. Returning home, was further motivated by the alternative presented in an email from Information Unlimited, offering to assemble a new GRA3 voltage multiplier circuit board for only $50.oo. Was then double determined to repair this damaged voltage multiplier for myself, if possible. 

Reluctantly... I returned once more to Radio Shack, bypassing the sales people, and called upon my own limited high school electronics knowledge base. Searching without further assistance through the many parts drawers, I remembered that when used in parallel, two 1/2watt 47Kohm resistors will work the same as a single 1watt 47Kohm resistor. Purchased parts from the same 'know nothing' clerk, two packs of five resistors, along with a new 25watt Soldering Iron. 

Delicately removed the burned out pair of resistors, and proceeded to clean up the burnt circuit board around the edges as best as I could. Carefully soldered in three new resistors, secured in placed on the reveres side, since there was more space on that back of the board. Possessing almost no previous experience assembling small electric bits such as these, so even to the best of my ability, it was a rather sloppy job was done in my opinion. All the same, the new parts were finally attached onto the board, and upon visual inspection, the necessary repairs at least seemed complete.

Knowing full well that my roughly done soldering job was most likely a fragile repair, gently reassembled the entire GRA3 High Voltage Power Supply. Then, with all black plastic protective covers returned to their proper places, was ready to attempt my first Lifter flight after making these much needed repairs....

Wired everything together with my favorite Lifter, slowly powered things up, and the darn thing Actually Worked! Am most thankful to have successfully repaired my original GRA3 Power Supply, done at a small fraction of what it would have cost to buy just a replacement voltage amplifier circuit, or perhaps one of the new and improved HV25, HV35 or HV300 Series High Voltage Power Supplies from Information Unlimited. Thus from now on, I'll treat this older GRA3 unit with a greater respect, and certainly consider its use more carefully in the future. So now then... back to the wacky science laboratory, and on to the next experiment!