strokedmaro
New Member
Im building a cnc machine and just got done building a controller kit. The kit is rated at a max voltage of 42Vdc. I purchased a toroidal transformer with dual 35Vac secondaries (wanted to parallel both 35vac secondaries together for approx 10 amps) However after asking a few "pros" some questions on construction I was quickly told that this was going to blow my driver chips.
Their reasoning was that AC voltage when rectified to DC increases the voltage by 1.414 times and that my 35vac when rectified would be roughly 49.49Vdc. (35 * 1.414=49.49) I plugged the tranny in and measured 34.89Vac before the bridge rectifier and about 30.5VDC output of bridge rectifier. these readings were with no load.
I can understand how amperage is increased and decreased but how can rectification cause a voltage increase?? Quite a few "pros" confirmed this but no one could explain why...so I turn to you guys (my experts )
If this is indeed true than is this example also true?:
a 12vdc power supply has a transformer output of 8.48vac (12 / 1.414) which when rectified produces the 12vdc??
I cant wrap my head around this one so any transformer guru's out there please give me a hand.
THANKS!!
Their reasoning was that AC voltage when rectified to DC increases the voltage by 1.414 times and that my 35vac when rectified would be roughly 49.49Vdc. (35 * 1.414=49.49) I plugged the tranny in and measured 34.89Vac before the bridge rectifier and about 30.5VDC output of bridge rectifier. these readings were with no load.
I can understand how amperage is increased and decreased but how can rectification cause a voltage increase?? Quite a few "pros" confirmed this but no one could explain why...so I turn to you guys (my experts )
If this is indeed true than is this example also true?:
a 12vdc power supply has a transformer output of 8.48vac (12 / 1.414) which when rectified produces the 12vdc??
I cant wrap my head around this one so any transformer guru's out there please give me a hand.
THANKS!!
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