Paul Kimbrel's Musing

So I ask my dad if he can bring our (okay… his) old rotor controller over. We’re sitting there eating dinner and I ask, “So how attached are you to that controller?” I can’t recall the answer, but it was about as direct as my question. So I ask again, “So how attached are you to that controller?” My mom pipes up, “What he’s asking is if it’s okay to break it?”

I’m not quite sure, but I think he said it was okay. Hope so!

I got a rotor controller for the sole purpose of harvesting the transformer. More on that in the next post. The other stuff I needed was the parts to the computer-to-rotor interface. From the FOD tracker website, I found the schematic of the interface: FodTrack Rotor Interface

I went through the schematic and pulled out the parts I needed:
1 - TLC7528 DAC (U1)
2 - LM324 Quad Op Amp (U2, U3)
1 - LM328 Dual Op Amp (U4)
1 - LM7805 5V Regulator
4 - 1N4148 Diode
4 - BC546 General purpose NPN Transistors

…and a bunch of resistors and capacitors, etc., etc.

Right. I also needed a potentiometer for the rotor. According to Doug’s project, I need a 10-turn 2k potentiometer. In other words, it takes 10 turns to go from 0 to 2k ohms. That number of turns is enough, if geared properly, to cover the range of the rotor. I got one (as well as the parts above) from mouser.com. The part number was #594-53411202 (Vishey 534-11-202).

I also needed a gear. Again, from Doug’s project…

From Small Parts, Inc. (www.smallparts.com) It is part #GD-4860, cost about $6. It is a 60-tooth 48-pitch plastic gear with a 1/4″ hole. Small Parts has a catalog full of cool stuff. Try to order some other stuff with the gear, to offset the shipping charge.

That was around 2000, so the price has gone up a bit. Not the part itself - but the shipping. $3.45 for the part (which is now GDS-48060-01) and $8.95 for shipping. FedEx no less (I’m a UPS kind of guy).

Next up… I need to get that transformer out of the rotor control box!