Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi DC, I presume your "standard variac" is 240Vac in and 0-280Vac out???Your standard C core is a gapped toroid with 7.5 inch outer diam and 4.5 inch inner diameter and 4.5 inch thick?? Would the cross section then be 1.5 x 4.5 inches??. What is the Cp your PIG is driving?? This should help me figure out what is going on.
Thankyou, Gerry R.
Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>I'm not sure, but we build a lot of these for our pigs and they limit current right at 30 Amps when used with a standard variac.We gap our cores at 100 mils using standard "C" cores measuring 7.5 inch x 4.5 x 4.5 inches and usually approx 125 turns on each unit.Dr. ResonanceHi D C, OK, then what am I missing???Isn't 120mh, 45 ohms reactance at 60 Hz??? and doesn't 45ohms limit the current to 5.3 amps at 240 Vac??? or are you assuming a secondary Cp that reflects back to the primary and cancels some of the 45 ohms reactance??? If so, what are your assumptions.Please tell me before I cut my gap too wide in the toroid ballast Im building.Gerry ROriginal poster: "D.C. Cox" <resonance@xxxxxxxxxx>No. 120 mH provides control with 30 Amps as the max amount that may be drawn.Dr. ResonanceHi Dr R,120mh is 45 ohms at 60Hz. At 240Vac, this would limit the current to 5.3amps or ~1.2KVA. Is this in error or Im I missing something??Gerry R