DE1102912B - Device for electric fishing by means of discharge oscillations of a capacitor - Google Patents

Description

Devices are known for electric fishing by means of current pulses introduced into the water, which, according to FIG. 1, consist of an inductor 1 connected to a direct current source 2 Capacitor 3 are made by switching means, e.g. B. an electric valve 4 in the form of a grid or ignition pin-controlled discharge vessel, periodically discharged into the water via electrodes 5., 6 will. With these devices, if the individual switching elements are suitably dimensioned, one occurs Zero going discharge oscillation, so that in the vicinity of the zero current crossing after completion of the first half-wave the valve automatically interrupts the oscillation process or another switching means can be opened without current. In addition, the charging takes place in the form of an oscillation, the is generally a half-wave and by opening the valve 4 or some other switching means the discharge oscillation to be initiated is replaced. During this charging oscillation it charges the capacitor to a voltage which is considerably higher than the voltage of the supply current source. Such Facilities have proven particularly effective for fishing in salt water. They practically give all of the energy supplied by the charging current source is released into the water in pulse form. If the Pulse duration is small relative to the pulse pauses, the power of the charging current source needs in proportion to be only small to the pulse power.

The physiological effect of impulses on the fish is, apart from a certain impulse shape, voltage and current also depend on the number of pulses per second (pulse train) that are used for the different applications can be very different. With a very fast pulse train or If the pulse duration is not sufficiently small in relation to the pulse pauses, the case may arise that the Discharge current of the capacitor no longer goes through zero because the charging current of the capacitor was previously has already risen too much. The switch in the discharge circuit of the capacitor cannot then interrupt more currentless. If a discharge vessel is used as a switch, it can no longer operate automatically interrupt.

The object of the invention is to remedy this deficiency.

As a remedy, one could think of placing an additional inductance in the discharge circuit, which the damping of the discharge oscillation is reduced. Such an additional inductance would not only mean a further effort, but also an extension of the pulse duration and deformation which result in impulses, which can impair the physiological effects.

Equipment for electric fishing

by means of discharge vibrations

a capacitor

Applicant:

Siemens-Schuckertwerke

Corporation,

Berlin and Erlangen,

Erlangen, Werner-von-Siemens-Str. 50

Dipl.-Ing. Wilhelm Kafka,

Tennenlohe-Tunnberg via Erlangen,

has been named as the inventor

It has now become known through British patent specification 704 345, for the generation of capacitor discharge pulses to use an arrangement in which the capacitor has an electric valve and a choke coil and charged via a grid-controlled gas discharge vessel to the consumer is discharged. So that the charging voltage of the capacitor does not increase after discharge rapidly increases again and thereby the risk of unintentional reignition of the discharge vessel occurs, the inductance of the discharge choke should be very large. To reduce the effort it is designed as an air gap throttle, which does not go into saturation even at the maximum value of the charging current and whose air gap is partially bridged by iron webs of such a dimension that this is already at a certain amount of the charging current can be saturated. In another embodiment the inductance is formed by two core chokes, one of which is dimensioned so that it is a relative has low inductance and a saturation point above the charging current, and others is designed so that it has a relatively high inductance and saturation even at low charging currents goes. In this way, instead of a flattening of the charging current rise, only one up to saturation of the Low-current pause reaching isthmus webs or the core with a low saturation point is generated, during which the ionization of the discharge vessel goes back so far that self-ignition is no longer possible can occur.

109 537/442

Of these known circuit measures, the present invention makes in a fishing device beneficial use. The invention relates to a device for electric fishing by means of periodic repeated, through the water running discharge oscillations of a capacitor, which in a charging oscillation circuit containing the charging current source and a choke coil. According to the invention In such a device, on the one hand, in a manner known per se, the choke coil consists of a even at the maximum value of the charging current not yet saturated air gap choke coil and from one with your second connected in series, already saturating at a certain partial amount of the charging current, iron-closed inductor, or both inductors are in a single air gap inductor summarized with partial bridging of the air gap by iron webs, and also is According to the invention, an additional winding on the saturation choke for an adjustable displacement of the saturation point and thus the change in the pulse sequence serving direct current bias intended.

The invention is explained in more detail with the aid of the drawing. In Fig. 2, the discharging and charging process in the known device of FIG. 1 is illustrated. It is assumed that the capacitor 3 has been charged to its full voltage and the discharge vessel 4 is ignited _{at time i 0.} The discharge current J _{e of} the capacitor rises steeply to a maximum in accordance with the relatively low inductance in the discharge circuit and then falls somewhat more slowly until it becomes zero at time t _t. At this moment the discharge vessel interrupts the discharge circuit. During this time, the capacitor voltage has dropped from its maximum value through zero to a negative maximum. The charging current / _; was at time i ₀ z. B. zero, because the discharge vessel 4 was ignited at the zero crossing. At first it sinks a little. At the point in time when the capacitor voltage U _c intersects the generator voltage U _g , it reaches its negative maximum and then rises again. At time t _{1, it may} have already reached a noticeably positive value. The greater the positive charging current near the point in time t _t , the more the course of the discharge current J _e flattens out and can possibly take the course drawn in dashed lines, which no longer leads to a zero crossing and the automatic extinction of the discharge vessel 4 (Fig. 1) prevents or makes it more difficult to open a switch replacing valve 4.

The charging process of the capacitor begins at time t _i. The voltage U _c swings through zero to a positive maximum, which is considerably higher than the voltage U _{g of} the charging current source, and reaches this at time i ₂ . During this time, the charging current / _z takes the course shown. At time t ₂ , valve 4 is ignited again, so that the process is repeated.

The greater the time f ₀ to J ₁ compared to the time t _t to t ₂ , the greater the charging current must be, the greater the charging current at time t _t and therefore the greater the impact on the course of the discharge current in act near the zero crossing.

If you now form the inductor 1 lying in the charging circuit according to the invention so that it is at im Relation to the maximum charging current small currents absorbs a certain voltage-time integral and has an approximately constant inductance for larger currents, this results in accordance with FIG. 3 the following:

The diagonally hatched area corresponds to the voltage-time integral recorded by the choke. While this voltage-time integral is being recorded, the inductor current or the charging current changes only by a very small amount between a negative and a positive value. Accordingly

ίο the discharge current J _e in the vicinity of the time t _{x is} not influenced by it. So to a certain extent a gap arises in the charging current, which can range from t ₃ to t _i.

In order to achieve this effect, the throttle 1 (Fig. 1) can be designed as an air gap throttle whose Air gap on a small fraction of its total area is bridged by iron webs, which are already saturate at low currents. From this saturation point on, the throttle behaves like one

zo normal air gap choke and therefore has an approximately constant inductance.

The charging throttle can be designed, for example, according to FIG. 4, in which the U-shaped core is denoted by 7 and the yoke is denoted by 8. Between these two parts there is an air gap δ, which is bridged by saturation webs 9 at three points each, for example. The inductor winding is designated by 10, 11.

Instead of such a throttle, according to FIG. 5, a simple one can also be inserted into the charging circuit of the capacitor 3 Air gap choke 1 can be placed in series with a saturation choke 12, the latter being so designed is that it goes into saturation at low currents in relation to the maximum charging current and the voltage-time integral illustrated in FIG. 3 records. To this end it can be beneficial the core of the saturable choke 12 made of a material with a sharply bent magnetization characteristic exist.

If the choke according to FIG. 4 or the choke 12 in FIG. 5 is given an adjustable direct current bias, then the voltage-time integral or the length of the low-current pause and thus the pulse sequence can be changed continuously. If one increases the voltage-time integral with the help of the premagnetization and thereby shifts the point in time t _i to the right, the charging current /; of the capacitor accordingly later and reaches its maximum value and its next zero value all the later, at which z. B. the new discharge is initiated. In other words, this increases the time between I ₁ and i ₂ .

It can be useful to build such chokes with premagnetization from two cores and the To switch the bias windings against each other in a manner known per se in order to reduce the To make alternating voltages outwardly ineffective. To reduce the copper expenditure you can the bias windings when using an air gap choke with saturation bars as well be accommodated directly on these webs. There is the possibility of using the individual windings to switch with one another so that the alternating voltages induced in them are directed towards the outside cancel at least in part. If necessary, the direct current bias of the choke can be used also cause the fact that a third leg is provided, the cross section of which corresponds to the cross section corresponds to the aforementioned saturation bars and which carries the bias winding. The retroactive effect

on the DC bias circuit is then also only very slight.

Claims (2)

Patent claims 1. Device for electric fishing by means of periodically repeated, running through the water Discharge oscillations of a capacitor, the charging current source and a The charging oscillation circuit containing the inductor is located, characterized in that on the one hand the choke coil in a manner known per se from an even at the maximum value of the charging current not saturated air gap choke and from a second connected in series with it, already at a certain partial amount of the charging current there is a saturating, iron-closed choke coil or both chokes in a single air gap choke coil with partial bridging of the Air gap are structurally summarized by iron webs and that also on the saturation choke In addition, a winding for an adjustable, the shift of the saturation point and so that the change in the pulse sequence serving direct current bias is provided. 2. Device according to claim 1, characterized in that the premagnetized choke in two chokes each with a bias winding is divided, the bias windings are switched against each other. Considered publications:
British Patent No. 704,345. 1 sheet of drawings © 109 537/442 3.61