I don't think that a 6.3VAC transformer would give enough voltage headroom. You must take the ripple into account. I would advice a 9VAC transformer, that would give 12.72V. Take at least 1.2V because of the rectifier bridge (I would expect about 1.6V to 2.0V), and take the ripple voltage. You will need to supply an input voltage of at least 8V at the regulator's input to get the voltage regulated. And that is the absolute minimum.Your power supply page needs some clarification, you indicate the use of a 12VAC 500ma transformer which is in turn full wave rectified...
So it would be 16.9 volts not 12V as you indicate in the schematic. You'll also need a heatsink on the regulator as it's going to get very hot.
I suggest you use a 6.3VAC 500ma transformer (9V) as the circuit will run much cooler.
|Thread starter||Similar threads||Forum||Replies||Date|
|Free Or Low Cost Dictation Software?||Off-Topic||5|
|I||Microcontroller with free IDE||Microcontrollers||18|
|B||MIcrocontroller with free compiler||Microcontrollers||1|
|B||Free microcontroller projects with source code & Circuit||General Electronics Chat||2|
|B||Free microcontroller projects with source code & Circuit||Microcontrollers||2|
by Jake Hertz
by Gary Elinoff