primary current calculation

[nickblake]

If you take the soldering iron wattage of 18 watts even though its a transformer the primery current will be roughly the same as if it was 230 volt , reason for this is the lower the voltage the higher the current , so if you have you 24volt 18 watt soldering iron the current on the secondary will be 0.75 amps but the primery wattage would be calcultaed by using the same method but 230 volts so 18 /230 0.078 amps so if you have 20 soldering irons at 20 x 18 watts = 360 watt so 360 / 230 = 1.6 amps

 

[telectrix]

i'd calc. by the wattage 360w/230= 1.565A, then allow for losses ( 5% ), design current =1.65A.

 

[topquark]

Ohh!, I see, so it's the current that's being accounted for taking into account the primary winding voltage

 

[trebor]

Now thats wet everyones appetite heres the rest attached, perhaps Lenny can move it somewhere more suitable