International Business Machines Corporation

Yves A Bonnet

Christian A Jacquart

Michel F Ferry

Bruno Centola

Jacques Cresp

Jean-Pierre L Suzzoni

Daniel Ballatore

Dominique Baron

Jean-Marie Limon

The connecting device includes a securing plate and locking spring attached to the cable connector of the cable-to-card connectors. The connecting device is pressed, when the connectors are mated, by the front portion of the cable connector against the host machine chassis which in turn is pressed flat against the adapter card brackets. In a preferred embodiment the connecting device is attached on the front portion of a standard cable connector with removable fastener, in particular with a locking spring. In another embodiment, the connecting device is an integral part of the cable connector.

Connecting device for large cable-to-card connectors

The circuit of the present invention detects variations of a current I.sub.L flowing in a telephone line LL. A low-value resistor r is connected in series with line LL. A constant voltage generator is connected across this resistor. The current Is applied to resistor r by the contant voltage generator varies as a function of I.sub.L. This being so, a measurement of the variations of Is will reflect variations of I.sub.L and, therefore, can be used to detect both amplitude and directional variations of I.sub.L.

Circuit for detecting current variations

This invention relates to a circuit for holding a pulse at an up level during a time interval .tau. after the input signal has been removed, and to the use of the circuit to realize a monostable multivibrator. The holding circuit features a bipolar transistor that is driven into saturation by the application of an input signal in the form of a clock pulse. The hold circuit also features a control network including a diode and a drain resistor. Upon removal of the input signal the charge stored in the base of the saturated transistor is caused by the diode to flow in a controlled manner to the drain resistor so that the transistor is cut off after a time interval .tau. closely approximating the storage time t.sub.s. Thus, the holding circuit provides a pulse of width T+.tau.. A monostable multivibrator is obtained by connecting the holding circuit to one of the two inputs of a conventional NOR circuit. The other NOR circuit input receives the input clock pulse. Because of the absence of capacitors these circuits can readily be fabricated as a monolithic integrated form.

Circuit for holding a pulse during a predetermined time interval and an

This interface circuit between a bidirectional line (Lg) and a telephone exchange includes a high frequency transformer (Tr) whose secondary (N2) is connected to said line through a detector circuit (DET) and whose primary (N1) is connected to the switching network of said telephone exchange and to a high frequency carrier source. The circuit further includes means for adjusting the impedances seen across the points where the telephone line is connected to the exchange, so as to meet specified values applicable to the particular location of the exchange. The impedance adaptation means include means (A1) for amplifying the line current variations seen at the center tap (K) of the high frequency transformer (Tr), addition means (.SIGMA.1) for adding the output from (A1) to the voice signal to be sent to the telephone line (Lg), and second amplification means (A2) responsive to the output from (.SIGMA.1) to drive said center tap (K).

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Saint Laurent Du Var, France

Yves A Bonnet