Hi Don,
Yes, both the voltage and current are measured at the transformer's primary.? The voltage does not include the voltage across the dim bulb.? A transformer transforms voltage according to the secondary/primary turns ratio and current by the inverse ratio.? The primary on this transformer has about 250 turns and the shorted secondary only one turn.? Without the shorted turn, the primary current in phase with the voltage is about 200 mApp which is about 70 mA rms.? Subtracting that from the 190 mA rms yields about 120 mA rms attributable to the shorted turn.? Multiplying that by 250 gives 30 A, which is quite a hefty but not unreasonable current to flow in that turn.?
Hi Jim,
I use pp values for my convenience, not because I have to.? They're easy for me to read from the graph.? The transformer is not inside my transmitter; it's a damaged transformer from another HT-37. ?There was a leak between HV and filament windings, but that is under repair now, not investigation.? The purpose of investigating the symptoms of a short between adjacent windings is so that once reassembled, I'll be able to assess electrically whether this transformer has developed such a short during the repair effort.?
Cheers,
Halden VE7UTS
