Browse Prior Art Database

Drive For Card Capacitor Memory

IP.com Disclosure Number: IPCOM000097909D
Original Publication Date: 1961-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Shortle, JK: AUTHOR

Abstract

The driver eliminates crosstalk effects in a card capacitor memory and provides an input signal to it having a minimum pulse width.

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Drive For Card Capacitor Memory

The driver eliminates crosstalk effects in a card capacitor memory and provides an input signal to it having a minimum pulse width.

Only one of the drivers is shown. Included in the driver is transistor 20 connected as a common emitter. Inductance 22 connects the collector of 20 to bias supply 23 through load resistor 24. Diode 26 and resistor 28 are connected in parallel with 22 and function as a dampening circuit. The output from 20 is supplied through transmission line 30 to card capacitor memory 32. Capacitor 34, together with a capacitor 35, forms a tank circuit with 22. Completing the drive circuit is diode 38 which limits the degree of cutoff of 20, thus aiding turnon of 20.

Normally, transistor 20 conducts so that all drive lines to memory 32 are at ground potential which prevents crosstalk. When 20 is turned off by a pulse, an output signal is applied to 30 from source 23. Also, the energy stored in 22 is transferred to 34 resulting in an oscillating condition developing in the tank circuit.

As the oscillation builds up, the voltage polarity across 22 changes. This forwardly biases 26 and causes the oscillations in the tank circuit to be dampened through the resistance of 26 and 28. Diode 26 and resistor 28 are selected so that oscillations in the tank circuit terminate at a preselected interval, e.g., at the end of the first half-cycle. As a result, the circuit provides a signal to the memory of minimum pulse width.

Capac...