A adrian sphank New Member Feb 11, 2009 #1 C1 = 470uf C2 = C3 = C5 =0.1uf C4 = C6 = 100uf R1 =R2 =IK Transformer = 9v – 0 – 9v REG 1 = LM7812 REG 2 = LM7805 Circuit attach will produce 12v and 5v at the output. How do I change this circuit to get a 15v and 5v at the output? I know that LM7815 voltage regulator will produce 15v at the output. But how do I implement LM7815 to this circuit?
C1 = 470uf C2 = C3 = C5 =0.1uf C4 = C6 = 100uf R1 =R2 =IK Transformer = 9v – 0 – 9v REG 1 = LM7812 REG 2 = LM7805 Circuit attach will produce 12v and 5v at the output. How do I change this circuit to get a 15v and 5v at the output? I know that LM7815 voltage regulator will produce 15v at the output. But how do I implement LM7815 to this circuit?
ericgibbs Well-Known Member Most Helpful Member Feb 11, 2009 #2 adrian sphank said: C1 = 470uf C2 = C3 = C5 =0.1uf C4 = C6 = 100uf R1 =R2 =IK Transformer = 9v – 0 – 9v REG 1 = LM7812 REG 2 = LM7805 Circuit attach will produce 12v and 5v at the output. How do I change this circuit to get a 15v and 5v at the output? I know that LM7815 voltage regulator will produce 15v at the output. But how do I implement LM7815 to this circuit? Click to expand... hi, No circuit visible.
adrian sphank said: C1 = 470uf C2 = C3 = C5 =0.1uf C4 = C6 = 100uf R1 =R2 =IK Transformer = 9v – 0 – 9v REG 1 = LM7812 REG 2 = LM7805 Circuit attach will produce 12v and 5v at the output. How do I change this circuit to get a 15v and 5v at the output? I know that LM7815 voltage regulator will produce 15v at the output. But how do I implement LM7815 to this circuit? Click to expand... hi, No circuit visible.
E elnino86 New Member Feb 11, 2009 #3 ericgibbs said: hi, No circuit visible. Click to expand... Hi,sorry.I thought i uploaded it juz now..Here it is. Attachments voltage regulator.JPG 40.6 KB · Views: 921
ericgibbs said: hi, No circuit visible. Click to expand... Hi,sorry.I thought i uploaded it juz now..Here it is.
MrDEB Well-Known Member Feb 11, 2009 #4 Must be typo How do you get 12v from a 9v transformer mush less the 15v you want?? I am pretty the regulator needs more voltage. I recall 2-3 volts above desired voltage??
Must be typo How do you get 12v from a 9v transformer mush less the 15v you want?? I am pretty the regulator needs more voltage. I recall 2-3 volts above desired voltage??
O Oblong New Member Feb 11, 2009 #5 Use a bridge rectifier on the output see **broken link removed** page bottom. This will give about 18VAC secondary into the bridge then select a filter capacitor.Then put in your 7815. More detailed design references here. http://elearning.algonquincollege.com/coursemat/saurioc/ELE-3/ELE-3-NOTES/VOLT-REG.pdf essentially onsemis handbook which you can get here. ON Semiconductor Last edited: Feb 11, 2009
Use a bridge rectifier on the output see **broken link removed** page bottom. This will give about 18VAC secondary into the bridge then select a filter capacitor.Then put in your 7815. More detailed design references here. http://elearning.algonquincollege.com/coursemat/saurioc/ELE-3/ELE-3-NOTES/VOLT-REG.pdf essentially onsemis handbook which you can get here. ON Semiconductor
audioguru Well-Known Member Most Helpful Member Feb 11, 2009 #6 The 9V-0-9V transformer has a peak of 12.7V and the rectifiers reduce it to 12.0V. Ripple from the small filter capacitor reduces it further. But the original LM7812 needs to have a minimum input of 15V. Therefore the original circuit will not work.
The 9V-0-9V transformer has a peak of 12.7V and the rectifiers reduce it to 12.0V. Ripple from the small filter capacitor reduces it further. But the original LM7812 needs to have a minimum input of 15V. Therefore the original circuit will not work.