M307

This document is a schematic diagram for the Digital Equipment Corporation Integrating One Shot circuit, model M307-0-1, copyrighted 1970.

Key features and information:

• Purpose: The schematic is provided for test and maintenance, and the circuits are proprietary.
• Functionality: It describes an "integrating one-shot" circuit, which is a type of monostable multivibrator designed to produce a single output pulse of a specific duration in response to a trigger input. The "integrating" aspect suggests its timing mechanism.

• Components:

  • It uses DEC 3009B transistors (EIA equivalent 2N3009), 1/4W 5% resistors, and 100V 5% capacitors.
  • Integrated circuits include DEC7400 series (E1, E3, likely logic gates) and 9601 ICs (E2, E4), which are common monostable multivibrator chips.
  • Potentiometers (R4, R8) and two 2-pole, 5-position Spectrol switches (S1, S2) are used for adjustment and range selection.

• Timing Ranges: The circuit provides five selectable output pulse duration ranges:

  • Range 5: 5 µsec - 50 µsec
  • Range 4: 50 µsec - 500 µsec
  • Range 3: 500 µsec - 5 msec
  • Range 2: 5 msec - 50 msec
  • Range 1: 50 msec - 500 msec

• Power Supply: The circuit operates with +5V and -15V power rails, and multiple ground connections.

• Authors & Date: The document was drawn, checked, and engineered by M. Haller, A. Yauga, and R. Schwegler in September 1969.