G821 +5V Regulator

The G821 module is a voltage regulator designed for the PDP-15 memory. It provides regulated +5V power with integrated protection against over-voltage, under-voltage, and over-current conditions.

Key Technical Details:

• Input Requirements: Powered by a 715 power supply, it requires +8V, +11V, -15V, and ground, along with power OK signals from G822 and G823 modules.

• Outputs:

  • +5V: Variable from 4.5V to 5.5V. Rated for 7A with adequate fan cooling; otherwise limited to 2A.
  • +11V: Rated at 1.0A maximum.
  • -15V: Rated at 3.0A maximum.

• Logic Functions: The module includes combinational logic circuits and open collector drivers:

  • BM1 (Lamp Driver): Turns on when the 5V output is within established limits.
  • BR1 (Memory Power OK): Turns on when the 5V output is outside of established limits.

• Adjustments: The 5V output level and the voltage detection limits (typically set at 4.75V for the lower limit and 5.5V for the upper limit) are controlled via potentiometers.