DD204328A1 - CIRCUIT ARRANGEMENT FOR AN INPUT KEYBOARD - Google Patents

Abstract

The invention relates to a circuit arrangement for an input keyboard in the field of digital technology, in particular for parallel buffered input systems. It is applicable to the characterization of sampling points in digitizing processes. According to the invention, this is achieved by a circuit arrangement consisting of keys with e which is applicable in the characterization of sampling points in digitizing processes. According to the invention this is achieved by a circuit consisting of keys with switching contact sets, resistors, memories with charge inputs and negators. At all memory inputs lies in the ground state ( no key pressed) low-signal and on the charge in the memory and the old contents deleted. This state is retained when the button is not pressed, since when the button is released, the Higth signal on the memory set is transferred to the memory and the old content is deleted. This state is retained when the button is not pressed, since when the button is released the high signal is stored

Description

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Circuit arrangement for an input keyboard

Field of application of the invention

The invention relates to a circuit arrangement for an input keyboard in the field of digital technology, in particular for parallel operating buffered input systems. It is applicable to the characterization of sampling points in digitizing processes.

Characteristics of the known technical solutions

Are known a variety of electronic devices * such as electronic calculators, electronic calculators or remote control arrangements for Pernseh- or radios, which are controlled by input keyboards. The input keyboards generally consist of push buttons with single or double contacts and another circuit. When operated, electrical connections to the data processing system are made and resolved. Depending on the application, the connection of the buttons is uncoded, coded or arranged in a matrix. From the Auslegeschrift (DE-AS 2756327) is a circuit arrangement for an input keyboard with a matrix arrangement consisting of m-columns and η-lines known.

In this solution according to the invention, only one memory is to be used per row or column ". By the additional use of electronic switches and the subsequent decoding

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the row and column encryption requires such a circuit, a high cost of components «Furthermore, a keyboard layout for data input devices is known (DE-AS 1574β? ο).

Every single key generates a pulse _? which causes the acquisition of a corresponding character in a memory via a coding circuit. A further disadvantage is that the circuit arrangement is not decoupled from bouncing contacts, thus no defined initial state is given during this phase.

Object of the invention

The aim of the invention is to develop a parallel operating buffered input system with η input keys and to reduce the complexity of components.

Explanation d the essence of the invention

The invention has for its object to input digital information inputs by means of keys in a memory and delete the old content at the same time »invention, the object is achieved» that the first input of a memory with charging input is connected to the output of an inverter and whose input to the Normally closed contact of the first push button and connected to the first connection of the first contactor »

The second terminal of the first resistor is connected to the first terminal of the second, third, ηth and (n + 1) th resistors.

The second, third and nth inputs of the memory with charging input are connected to the normally closed contact of the second, third and nth pushbuttons and to the second connection of the second, third and nth resistors

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The charging input of the memory is connected to the second terminal of the (n + 1) -th resistor and the normally open contact of the first, second, third and η-th button, wherein the switching contacts of the first, second, third and n-th button linked together sind®

By means of the circuit arrangement according to the invention, the three states of a change-over contact in the case of a pushbutton for a digital information input in a memory with Iia.de unit are used technically and thus a cost-effective solution dujpssft. Saving on components created,

embodiment

The invention will be explained in more detail below using an exemplary embodiment.

In the accompanying drawing, s

Fig. 1 circuit arrangement for an input keyboard

The circuit arrangement according to the invention serves as an input keyboard for digital information in a memory with charging unit, wherein the principal task of a changeover contact is utilized.

At the memory inputs E ₂ * ··. , E _n is in the basic state (no key printed) Low signal or, at the memory input E ₁ High signal and at the charging input L of the memory 4 High signal _o

When the key 1,2 (pressed state) is pressed, the storage input Eg has high signal and the charging input L low signal. "Thus the high signal appears at the output Q ₂ , whereby the old content of the memory is deleted. This state is maintained when the key 1.2 is released, since the high signal at the memory input E ₂ is applied for a longer time than the low signal at the load input L. The signal states when pressing the keys 1.3,. n.

When pressing the key 1.1 (pressed state) has the memory input E ₁ through the negator 3 low signal and the charging input L low signal,

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Thus, the low signal appears at the output CL and is negated by the negator 5 for the amplifier and the display β.

The old content of memory 4 is cleared. The memory 4 is reset with a high signal at the reset input. The memory contents are indicated by the display with amplifier 6.

The interface decoder 7 provides the memory contents encoded ready for further processing

For the input expansion of the memory 4 n-inputs can be addressed. The number η is limited by the contact set and their current carrying capacity, since the sum of all charging currents flows through the contact set.

When implementing the memory 4 with several memory groups, the charging and reset inputs are to be connected in parallel.

Claims (1)

238475 5 invention claim Circuit arrangement for an input keyboard by means of keys and resistors, in particular for a digitizer, as a result of that the first input (E.) of a memory with charging input (4) is connected to the output of an inverter (3) whose input is connected to the normally closed contact (b) of the first button (1.1) and to the first terminal of the first resistor (2, 1), wherein the output of the first resistor (2 ₀ 1) with that of the second, third to η-th and (n + 1) th resistor (2.2; 2 "3;···; 2.nj 2 · Η + 1), the second, third to nth inputs (E ₂ ; E ^; _e . _# ;, E) of the memory with charging input (4) to the normally closed contact (b) of the second, third to n and the input of the second, third, or nth resistor (2 _e 2, 2,3; ·, ··; 2.n) is, the charging input (L) of the memory (4) with the input of the (n + 1) th resistor (2 n + 1) and the normally open contact (c) of the first, second, third to η-th button (1. T; 1 _c 2j 1,3; ··· 1.n), wherein the switching contacts (a) of the first, second, third to η-th buttons (1.1, 1.2, 1.3; ···; 1 «n) are interconnected. For this 1 page drawings