Building Core, Stage 2

<1) I'm using copper clad board to provide a ground plane "under" the core. <After my last message it became obvious that this was the other half of th <winding "through" the core. Not required. Any whire with durrent passing through it has a field around it. That is all that is required. More turns only reduce the current required to attain a given field. <2) I'm using "magnet" wire (enameled copper wire) for the core wire. I'm <guessing it can take a couple of amps for a short period of time. I'm not <sure that is sufficent to "switch" the #2 nut I'm using but we'll see. The current can be quite high as those pulses will be short (microseconds). <3) Allison referenced a waveform that looked like this: Keep in mind that will switch the core in both directions. that was mostly a test signal for trying materials. <4) The diagram in the 8a manual shows the sense wires going through one se <of cores, looping and coming back through another set. The sense wire is <also used as the 'inhibit' wire when one wants to write a zero. This is <done by reversing the X or Y current so that the selected cores don't get <full write current (and thus don't switch.) Yep the two matic selects and the sense/inhibit wire. Some planes used four wires with the inhibit being seperate. <5) So this is the plan: < put three wires through the nut and wire them up as follows: < -- < 1/h select ----------\ | | /----- GND < 1/h select ---------------| |-------------- GND < sense + ----------/ | | \----- sense - For testing a "core" only two are needed. makes life simpler. < The scope will display the current on the select lines on channel 1 < the sense lines on channel 2 (floating ground) Good! <6) When the current is sufficient, I should see a pulse on the sense line. < (This is the hypothesis part, now to apply the scientific method) Actually even if the current is low there will be a pulse coincident with the drive pulse (transformer action). However when the core switches the waveform will not corospond to a 1:1 transformer and also it will be shifted in time. If the core is not suitable the signal may not be visible. Allison