This I gotta see.
The laminations are grain oriented silicon steel from 1976.
The core is called EI 138
The stack height is 1.109 inches (including enamel coating)
The length along the leg side is 2.85 inches
The width across the 3 legs is 1.375"
The primary winding is 212 turns of #20 single enameled magnet wire.
What is the RMS idle current at 123.0 VAC RMS applied input?
Hi there,
We also need to know what kind of material it is and what thickness the laminations are
and what the frequency of operation is. I'll assume 1x1 interleaving just to keep it simple.
Also, the stack height is about 1.1 inches but just to make sure is the center width about 1.375 inches across or something else? That's the width of the center portion of the core only.
We know the primary turns, that's good, and we know the operating voltage, that's good too.
Now we need to specify the center width and type of material and frequency.
I could not find any data on line for a core EI138 of any type of material (didnt look real hard yet though) but i do have data for a core EI1 1/2 (that's EI one and a half) which may be close to the size you are talking about. I have data from about the same period for core types M19 26 gauge, M6 Orthosil 29 gauge, and Orthosil 0.006 inch. I also have 10KGauss data for a few other cores on hand, but anything else would have to be obtained from the manufacturer.
Basically the procedure would go something like this...
1. Using the dimensional data, calculate the weight
2. Using the voltage and frequency, calculate the flux density
3. Find the right curve for the right material at the right frequency with the same interleaving
4. Look up the exciting volt amperes per pound
5. Multiply the pounds times the value found in step 4 above
If we dont know and can not get the right material data, we can estimate but from the data i have i can already see that with different materials we can see a difference of 2 to 1 in the exciting volt amperes, so it would be best to know the material type too.
If we can not get the right material data i can give an example of a core using some known type of material (with published data) if that would help.