Amp Power Supply

  1. Installed Antek AN-5440 toroid transformer to the mounting bracket. Antek ships fast and answers questions. View the AN-5440 transformer specification sheet here. This transformer is rated for 500 VA. Two primaries wired in parallel and connected to 120V main. Four secondaries: two 40V, one 12V, and one 18V. The two 40V secondaries wired in series with the center connected to ground and the other two leads connected to the bridge rectifier. The 12V and 18V secondaries will be used to test the amplifiers however will not be used for normal operation.

    Pi-Amp Rev 5 Amp Power Supply Transformer 1

    The transformer sits on a foam pad to protect the windings. Also shown are the fuse buses mounted to the Power Supply Distribution Unit (PSDU).

    Pi-Amp Rev 5 Amp Power Supply Transformer 2
  2. Flipped the transformer around so the leads are outboard for easier management. Installed bridge rectifier and reservoir capacitors to the PSDU. Wired the primary windings to the mains, fuse, and face plate power switch. Wired the secondary windings to the bridge rectifier. Connected the DC out from the bridge rectifier to the reservoir capacitors and amp fuse bus. The power supply tested +/- 60V DC. The secondary showed 43V AC. That agrees with: sqrt(2) x 40V - 0.5V = 60VDC. A little hot (Leach specs 58VDC).

    Pi-Amp Rev 5 Amp Power Supply Transformer Wired 1

    Pi-Amp Rev 5 Amp Power Supply Transformer Wired 2

    Pi-Amp Rev 5 Amp Power Supply Transformer Wired 3

    The power supply is complete. Continue to Leach amplifiers.