Browse Prior Art Database

Stable High Efficiency Single Shot Circuit

IP.com Disclosure Number: IPCOM000092088D
Original Publication Date: 1968-Sep-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Roehr, WC: AUTHOR [+2]

Abstract

This circuit produces output pulses with minimum variation of time duration despite variations in temperature and supply voltage. The circuit also achieves very high efficiency by dissipating essentially zero power in the quiescent state. Q3 and Q4 are cut off when the circuit is in the quiescent state. A short-time duration positive pulse, applied at input A, turns on Q3 which turns on Q4 by supplying current to resistors R7 and R8. Conduction of Q3 is sustained by current flow through Q4, R3, VR1, and CR1 to the base of Q3.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 87% of the total text.

Page 1 of 2

Stable High Efficiency Single Shot Circuit

This circuit produces output pulses with minimum variation of time duration despite variations in temperature and supply voltage. The circuit also achieves very high efficiency by dissipating essentially zero power in the quiescent state. Q3 and Q4 are cut off when the circuit is in the quiescent state. A short-time duration positive pulse, applied at input A, turns on Q3 which turns on Q4 by supplying current to resistors R7 and R8. Conduction of Q3 is sustained by current flow through Q4, R3, VR1, and CR1 to the base of Q3.

Q1 and Q2 operate as a differential comparator with the supply voltage switched by Q4. Q1 and Q2 therefore dissipate no power in the quiescent state. When Q4 is conducting, point D is maintained at a voltage approximately the same as the voltage at point C due to the small base-emitter voltage drop in Q1. Q2 remains in the cutoff condition until the voltage across capacitor C1 rises to approximately the same potential as the voltage at point C. When the voltage at point B is approximately equal to the voltage at point C, Q2 begins conducting causing an increased voltage drop in R3. This lowers the potential at point E to a value where there is insufficient voltage across VR1 to maintain the zener potential. This in turn causes a starvation of base current from Q3 resulting in Q3 turning off. Such action causes Q4 to turn off which then removes supply voltage from Q1 and Q2 and the circuit resumes th...