# 12v power supply not putting out right voltage

Built a 12v power supply for music project. The "music from outer space" bipolar design, and my modules connected aint been working right. Tested the power output with multimeter and got 10v with a 1 amp wall wart and 23 volts with a 2 amp wall wart. Im super new to troubleshooting and dont really know what my next step is?

• Buy the right power supply – Sunnyskyguy EE75 Mar 26 at 2:19
• post a schematic. – Jasen Mar 26 at 2:19
• The right wall wart? Thats why i tried a second one cuz i thought the first was busted, but getting two different readings makes me think its the circuit. – offman_j Mar 26 at 2:39
• Note : Wall Wart MUST be AC - not DC. || Polarity of all diodes is important. CR3 or CR5 reversed will give you over voltage supplies. CR\$ or CR6 reversed will give you hot regulators and/or destroyed diodes. CR1 or CR2 reversed will give you bad juju and maybe magic smoke. | Be sure to note that LM7812 and LM7912 pinouts are NOT the same. The case is most negative in bioth cases so = gnd for 7812 and = Vin- for 7912. Output is pin 3 in both cases leaving remaining pin as remaining choice. | Capacitor polarities matter. – Russell McMahon Mar 26 at 4:24
• Assuming you actually are using AC adapters (not as common as DC), disconnect everything after the banks of 4 capacitors and add a $1\:\text{k}\Omega$ resistor across the capacitor banks (both of them.) That way you have just two diodes, 8 capacitors and the two added resistors. Measure the DC voltages on each side with respect to ground. Report values using each AC adapter. Also, may as well measure the AC voltage while it's slightly loaded like that (use AC range.) In short, work backwards and test. – jonk Mar 26 at 4:25