Browse Prior Art Database

Transistor Single-Shot Circuit

IP.com Disclosure Number: IPCOM000097686D
Original Publication Date: 1961-Apr-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Hines, HW: AUTHOR

Abstract

The transistor single shot circuit provides a desired pulse duration whenever the input is triggered. To obtain rapid transition times, a mesa transistor T3 is used connected in a grounded emitter configuration. The mesa transistor has the limitation that the base emitter junction cannot be reversely biased by a voltage greater than approximately one volt. In the circuit an isolation diode D2 is connected to the base of T3. This allows the use of mesa transistors without exceeding their break down voltage or destroying the time constant of the RC network. The output is from the collector of T3, while a clamping diode D3 is connected in the base emitter circuit.

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 85% of the total text.

Page 1 of 2

Transistor Single-Shot Circuit

The transistor single shot circuit provides a desired pulse duration whenever the input is triggered. To obtain rapid transition times, a mesa transistor T3 is used connected in a grounded emitter configuration. The mesa transistor has the limitation that the base emitter junction cannot be reversely biased by a voltage greater than approximately one volt.

In the circuit an isolation diode D2 is connected to the base of T3.

This allows the use of mesa transistors without exceeding their break down voltage or destroying the time constant of the RC network. The output is from the collector of T3, while a clamping diode D3 is connected in the base emitter circuit.

The input is through a resistor R1 to the base of a grounded emitter transistor T1. The collector of this transistor is connected to the base of another transistor T2. T2 is arranged as an emitter follower. Diode D1 also connects the collector of T1 with the emitter of T2, diode D1 being reversely biased when T1 is not conducting. The time delay is varied by a capacitor C, connected to the emitter of T2, and an adjustable, series resistor R6, connected to a source -E.

In the steady state, T1 is off when T3 is on and the input is at zero volts. Current for T3, when conducting, is supplied by resistor R6 through diode D2 which is forwardly biased. Upon application of a negative voltage at the input, T1 turns on, thus forwardly biasing diode D1 and passing current to capacitor C...