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Old 16th Oct 2021, 8:51 pm   #1
samjmann
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Join Date: Feb 2014
Location: Nottingham, UK.
Posts: 649
Default Transformer output current.

I'm replacing a mains transformer that's no longer available with a standard type. There are two secondaries of 19v, feeding two 200mA fuses.

The only transformer that will physically fit is rated at 6VA. Each secondary winding is rated at 3VA at 19vAC. From what I know the maximum secondary current per winding would be 3/19 = 157mA. Are my sums correct in this?

Assuming the manufacturer may have allowed 50% extra on the fuse rating:
Normal current draw 133mA plus 50% extra gives about 200mA the rating of the fuse.

I know what you're all thinking 'why doesn't he just measure it'? The reason being my DMM has now died on the current ranges!!

The transformer I'm looking at is RS stock code:504757

Thanks for any help or advice. SJM.
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