- Dec 24, 2004
The scope was working during the flat line test. The accident occurred when I disconnected the scope ground lead from the AC return. The AC circuit was turned off at the time. And it was always my understanding that return was ground. But this morning I was reviewing proper procedure and discovered that the ground lead is ALWAYS to be connected to earth ground. So at the time I didn't think I was doing anything wrong till the ground disconnect. Then the mini Chernobyl blue spark and puff of smoke occurred. And channel 3 no longer worked after that. But I still have use of channel 2 and 4.Excellent posting Einstein ..Maybe the "flat line" means another scope channel is "dead"..(my bad humour mate lol )I did check out the scope patterns on this yesterday. At the cost of losing another channel off my 4 channel PC scope. I'm down to 2 channels left.Shiny object!
Across the electromagnet there is a full sine wave pattern. After the electromagnet to the AC return there is the bottom half of a chopped sine wave. However what is there is very narrow. Flipping on the capacitor changes the waveform slightly. The waveform for the reversed voltage back to the electromagnet was interesting. It is mostly the upper half of a chopped sine wave with about 1/4 of the wave below zero reference. The dials change the voltage span of the waveform from 3 to 4 volts. And there is no waveform at all across the caduceus coil. Just flat line.
I have 2 electromagnets that I made for use with the HDR and MVR. One of them is constructed based on available info and the other was an initial attempt that wound up being a lot larger than available info suggested it should be. I did testing with both electromagnets and found that the available voltage left over after the electromagnet was not the same for each magnet. My initial super large electromagnet had -60 volts left over. Whereas my second attempt magnet had -100 volts left over. What that tells me is getting an electromagnet with the correct number of windings may be critical to obtaining the correct operation of these devices.
If anyone has an electromagnet made by Gibbs, and access to an ohmmeter, I would love to know the ohms reading for the electromagnet.