R450

This document is a schematic diagram for the Digital Equipment Corporation Variable Clock R450, copyrighted in 1965. It outlines the circuitry for a clock generation and pulse processing unit.

Key features and components of the R450 Variable Clock include:

• Functionality: The circuit appears to generate variable clock signals and process pulses, indicated by various "ENABLE GATE INPUT," "CLOCK OUT," "P.A. INPUT," "P.A. ENABLE," "P.A. DIODE INPUT," "400ns PULSE" input, and a main "PULSE OUT."

• Components:

  • Transistors: Primarily DEC 3639 (EIA equivalent 2N3639, PNP) and DEC 3009B (EIA equivalent 2N3009, NPN).
  • Diodes: Predominantly D-662 (EIA equivalent 1N645) and D-664 (EIA equivalent 1N3606).
  • Resistors: Generally 1/4 Watt, 5% tolerance, with specific part numbers listed for R4, R6, R16, and R18.
  • Capacitors: Specified in MMFD (micro-microfarads or picofarads).

• Power Rails: The circuit operates with +10V (A), -15V (B), and Ground (C).

• Proprietary Information: The schematic is explicitly marked as proprietary to Digital Equipment Corporation, furnished for test and maintenance purposes only.
• Revision History: The document includes a revision history chart, with the latest revision shown as 'H'.