DE2402858A1 - Control circuit for wire printer - is designed to facilitate attainment of constant impression energy via electromagnetic operating elements - Google Patents

Abstract

In order to attain constant impression energy, the supplied electrical energy is converted into kinetic energy through voltage-dependent regulation of the current flow time of the electro-magnetic operating elements in such a way that it remains constant within an associated operational cycle. The circuit comprises a symbol generator to which is fed the coded signal for the selected symbol, and a gate circuit leading to a switch which renders possible the flow of current to the electro-magnetic operating element (e.g. wire magnet of wire printer) through a voltage or current source. A time stage connected to the gate circuit ensures that the current flow time is reduced if the direct voltage is high or is increased should the voltage be small.

Description

Circuit arrangement for controlling electro-magnetic actuation elements in printers The invention relates to a circuit arrangement for controlling Electro-magnetic actuating elements in printers, especially in dot matrix printers.

For printers with electro-magnetic actuation elements, these are controlled to form imprints of characters or character elements in such a way that that the electrical energy supplied to the electromagnetic actuating elements is converted into kinetic energy with which the actual impression is made will.

Among such printers, the dot matrix printer is a printer at which - to reduce each a single electro-mechanical Actuating element assigned to be moved mass - the individual character as a grid of points is formed by several associated needle prints on the recording medium. It therefore represents a mosaic printer in which it is necessary to achieve an even and good typeface with constant kinetic imprint energy to work.

It is now known, in the case of printers, in particular of the type mentioned, with a constant voltage during a constant duty cycle time, during which the electromagnetic actuators are energized, too work.

Another known way of achieving uniform kinetic Impression energy consists in the energization of the electro-mechanical associated with the individual needles Actuators from a constant current source.

However, such known measures have considerable disadvantages, in particular what the required amount of circuitry and the power losses that occur regards. Thus, obtaining a constant DC voltage causes great power from the supply network, as they are for the control of such electromagnetic Actuating elements, preferably in dot matrix printers, is required, in particular as a result of voltage fluctuations in the supply network and as a result of load reductions, which the power supply unit, due to different point density individual characters, absorbing and compensating must, considerable effort and considerable Power losses.

The invention is based on the object of making these disadvantages known Circuit arrangements for controlling electromagnetic actuation elements with printers, preferably with so-called dot matrix printers, to overcome and the To train the arrangement so that the required effort is significantly reduced and at the same time the power losses that occur are considerably reduced. This is achieved according to the invention in that, in order to achieve constant impression energy the supplied electrical energy through voltage-dependent regulation the energization time of the electromagnetic actuation elements in such a kinetic way Energy is converted that the same within an assigned duty cycle regardless of different operating conditions, such as voltage fluctuations in the supply network, change or fluctuations in the load on the energy supply unit vsw., remains constant.

According to a further advantageous feature of the invention, the known time stage for determining the energization time or

-douer the electro-magnetic actuators via a control line between the voltage source or actuation element on the one hand and the timer on the other tracked in such a way that the energization time of the electro-magnetic actuation elements reduced if the DC voltage is too high, but increased if the DC voltage is too low will.

In an advantageous development of the invention, for the purpose a further adjustment of the required imprint energy to certain operating conditions, for example, printing on recording media (e.g. paper) of different types Quality or properties, the time stage for determining the energization time of the electro-magnetic actuating elements an additional manipulated variable of fed externally.

Further features and details of the invention are set out below explained with reference to the drawings. They show: FIG. 1 schematically a circuit arrangement known type for the control of electro-magnetic actuation elements, as they are used in mosaic or dot matrix printers, and FIG. 2 schematically a circuit arrangement according to the invention.

As can be seen from FIG. 1, in known control circuits of the type in question, code 1 of the character to be printed by a character generator 2 in the grid to be printed - indicated here schematically by a grid "A" - implemented.

A switch 6 is controlled via a gate circuit 3, with this Switch 6 the energization of electromagnetic actuators, z. 8. Needle magnet bie dot matrix printers 7, made possible by an energy source (voltage or current source) 8. The duration of this energization is determined by a time stage 5, so that on In this way, the supplied electrical energy is converted into kinetic energy of the actuation element, z. B. needle is converted.

In the circuit arrangement according to the invention as shown in FIG now the timer 5 is tracked by a control line 9 so that when too large DC voltage reduces the energization time; if the DC voltage is too low, this reduces it However, energization time is extended or increased. It can be seen that here the NuchfUhrchorecteristics can be trained without difficulty in such a way, that for every given case or for all occurring operating conditions, results in a constant imprint energy. In this case, the one according to the invention for this Tracking Required additional effort in time stage 5 is low.

It should be noted here that the individual building blocks described here are of the circuit arrangement to electronic components known to those skilled in the art acts, so that a closer look can be dispensed with.

In Figure 2 is also an advantageous development of the invention Circuit arrangement shown in which a further manipulated variable 9 of the timer 5 is supplied, thereby enabling the impression energy to be added to certain operating conditions can be adapted or adjusted to for example, to take into account the different types of paper used in printing.

The design and arrangement of the circuit according to Figure 2, in which the features according to the invention by dashed lines opposite-Uber per se known circuit measures are highlighted, compared to the latter simplest way not only a reduction in the required size of the power supply unit, but also a reduction in the power loss that occurs at the same time.

Moreover, it is also achieved that for the invention Circuit arrangement BouelemeRte with lower performance values than known ones Circuits can be used, which not only affects the size but also in has a beneficial effect on the prime cost in most cases; this results also from the fact that at the circuit arrangement according to the invention no voltage regulation with the necessary power semiconductors required is.

- Claims -

Claims (3)

Patent claim 3 circuit arrangement for controlling electromagnetic Actuating elements in printers, preferably in dot matrix printers, d u r c h it is not noted that in order to achieve constant imprint energy the applied electrical energy through voltage-dependent regulation of the energization time of the electro-magnetic Betötigungselemente (7) is converted into kinetic energy in such a way that the same within an assigned work cycle regardless of different operating conditions, such as voltage fluctuations in the supply network, changes or fluctuations the load on the power supply unit, etc., remains constant. 2. circuit arrangement according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that the per se known time stage (5) for determining the energization time or duration of the electromagnetic actuators via a control line (9) between voltage source (8) or actuating element (7) and timer (5) known control circuits is tracked in such a way that the energization time the electromagnetic actuation elements (7) reduced if the DC voltage is too high, however, if the DC voltage is too low, it is increased. 3. Circuit arrangement according to claims 1 and 2, d a d u r c h g e It is not possible to state that the time stage (5) for the purpose of further adaptation the required imprint energy to certain operating conditions, for example Printing on recording devices, e.g. B. Paper, different quality or Properties and the like, as well as another manipulated variable (9) from outside is fed. L e r s e i t e