US2415943A

US2415943A - Electric fence charging apparatus

Info

Publication number: US2415943A
Application number: US510307A
Authority: US
Inventors: William F Fagen
Original assignee: Stewart Warner Corp
Current assignee: Stewart Warner Corp
Priority date: 1943-11-15
Filing date: 1943-11-15
Publication date: 1947-02-18
Anticipated expiration: 1964-02-18

Description

Feb. 18, 1947. w; F. FIX GEN ELECTRIC FENCE CHARGING APPARATUS Filed Nov. 15, 3 Shegts-Sheet 1 Feb. 18, 1947. FAGEN 2,415,943

ELECTRIC FENCE CHARGING APPARATUS Filed Nov. 15, 1943 s Sheets-Sheet 2 Feb. 18, w, FAGEN 2,415,943

ELECTRIC FENCE CHARGING APPARATUS Filed Nov. 15, 1943 3 Sheets-Sheet 3 9% w%\ k. @Q K Iii-me min/n 3 a 2i? 3,42 741% a a2 oarne l s.

I is entangled with Patented Feb. 18, 1947 UNITED STATES PATENT'OFFIC 2,415,943 ELECTRIC FENCE CHARGING APPARATUS William F. Fagen, Chicago, Stewart-Warner Corporation, Chicago, Ill.,

corporation of Vir 111., assignor to a Application November 15, 1943, Serial No. 510,307

25 Claims. 1

The present invention relates to and more particularly to automatically operable fence energizers or chargers.

provide a new and improved fence charging ap-.

paratus of the character aforesaid, wherein the fence charging apparatus is controlled to provide 1 an impulse of energy in response to a change in an electric current, preferably a change in current fiow through the fence occasioned by contact between the fence and the body of an animal.

A further object of the present invention is to provide an electric fence charging apparatus wherein a relatively low voltage is normally applied to the fence voltage impulse is esponse to contact between the fence and the body of an animal. The use of a low normal or stand-by voltage has a number of advantages. Less difllculties are encountered'because oi circuit unbalance result branches brushing against the fence, and the like. Furthermore, the high voltage impulse is not produced as a result of contact between the fence and branches and the like.

A further object of the present invention is to and wherein a relatively high provide a new and improved fence charging apparatus wherein a single energy impulse is produced upon initial contact between the fence and the body of an animal, and wherein a plurality of such'impulses tacted sequentially by a plurality of animals.

Another object of the present invention is to provide a new and improved electric fence charging apparatus including a normally inoperative energy impulse supplying means which is rendered operative and effective to supply an energy impulse to the fence an animal comes into contact with the fence. This is of advantage in conditioning the animals to stay away from the fence.

electric fences,

g from dampness, showers,

occur when the fence is con- 'A further object of the present invention is to provide an electric fence charging apparatus of the electronic type comprising relay means, preferably of the electronic type, and a transformer inductively coupled to the fence, and having also means for producing a current impulse in the primary-of the transformer whenever an animal contacts the fence, thereby to provide a high passed through the fence in voltage energy, impulse of short duration.

A further object of the present invention is to provide an electronic fence charging apparatus wherein the energy impulse is substantially independent of the contact resistance between the animal and the fence.

A more specific object is to provide an apparatus of the character constant impulse is produced by effecting saturation of one or more of the electron tubes employed, and more particularly by utilizing a firstenergy impulse to produce a second energy impulseeffecting said saturation. The two im-" pulses occur substantially simultaneously so that there is in effect produced but one energy impulse which is transmitted through the fence to the animal.

Another more specific object is to provide an apparatus of the character specified in the second preceding paragraph wherein the energy impulse is made substantially independent of the contact resistance by means not requiring of a second energy impulse.

A further object of the present invention is to provide a new and improved electronic fence charger so constructed and arranged that a definite time interval must lapse before a second energy impulse can be produced.

A further object of the present invention is to provide a new and improved electric fence charging apparatus producing but a single energy impulse when'an animal contacts the fence, or which may be selectively periodic impulses, and in which, even though connected for the production of periodic impulses, an impulse is produced upon contact between the fence and an animal.

substantially immediately A further object of the present invention is to provide a new and improved electronically controlled fence charging apparatus so constructed and arranged that the electron tubes thereof will not be injuriously affected even though the im- A further object of the present invention is to provide an electric fence charging apparatus capable of producing a high voltage energy impulse but which does not require any high voltage power source.

provide a new and improve pulses applied to the fence are of high voltage and this high voltage ing apparatus wherein the sensitivity of operalast specified wherein the V the production arranged to produce tion may be adjusted readily in order that the apparatus may be adjusted to operate under varying atmospheric conditions producing different leakage resistances to ground and contact resistances between the fence and the animal coming into contact with it.

A further object of thepresent invention is to i provide anew and improved electric fence chargor which will operate more effectively despite var. iations in leakage resistance to ground. More specifically, it is an object or the present invention to polarize the fence wire positively by the application of a positive potential to the fence, whereby the leakage resistance to ground is considerably increased to render the operation of the apparatus more certain.

A further object of the present invention is to provide a new and improved fence charger oi the electronic type in which the requisite shocking impulse is produced by an electron tube which is rendered conductive in response to a control impulse and which passes considerable current to produce the impulse when rendered conductive.

Another object of the present invention is to provide an electric fence charger having lightning protection means.

Another object of the present invention is the provision of new and improved electric fence charging equipment which will not operate in response to stray voltages, such, for instance, as may be derived from high tension lines in proximity to the fence, unless the stray voltages are abovean abnormally high value.

Other objects and advantages of the present invention will become apparent from the ensuing description, in the course of which reference is had to the accompanying drawings, in which:

Figs. 1 to 3 are diagrammatic representations of various embodiments of the present invention.

The embodiment illustrated in Fig. 1 includes a fence charging apparatus l constructed in accordance with the present invention, the input of which is adapted to be connected through a plugv type connector 02 to a, suitable source oi power, such, for instance, as lli) volts alternating current, and the output of which is adapted to be connected to the bare conductive wire it of the fence and to ground through a. conductor it. An on-ofi switch it is utilized to control the supply of power to the apparatus.

The fence wire it may be supported upon a number of fence posts 2@ (of which only one has been illustrated), placed in the earth in conventional manner. It should be understood that in some installations it is preferable to use two fence wires, one corresponding to the single wire it illustrated, and the other to the earth or ground connection. It should be understood also that the term fence is not limited to fences for pastures or other enclosures for cows 0r horses or the like, but is intended to be broad enough to include protective safeguards for houses, rooms and thelike to prevent, or tend to prevent, human beings-from entering or leaving the premises.

The apparatus of the present invention includes a normally inoperative energy impulse producing means which is controlled in response to contact between the'fence wire and an animal to produce an energy impulse through the wire and the animal in contact with the wire. The appa= ratus includes in the main,-a source of power, control and amplifying. means, and impulse producing means, these being indicated generally by reference characters22, 2t and 28, respectively. The apparatus is so constructed and arranged lid till

that a'control voltage is produced when an animal contacts the fence. This control voltage is ampllfled by the amplifier 24 and produces a current impulse in the impulse producing means which in turn generates a voltage. The voltage thus generated is applied to the fence and also reapplied .to produce a further control voltage that is amplified and utilized to produce a further voltage impulse which is of substantially constant value and independent of contact resistance between the fence and the animal and which is applied to the fence to produce the requisite shock acting to deter animals and the like from leaving the enclosure. The two impulses occur so rapidly, however, that they constitute, in effect.

but a single impulse.

The power source 22 is illustrated as being of the electronic type, including a rectifier tube (preferably of the 5Y 36: type) energized by a transformer 32 and supplying a low direct current voltage preferably of about 300 volts across resistor 1 (of a value of about 50,000 ohms). The transformer 32 includes a primary winding 36 and three secondary windings t8, t0 and d2.

Winding 3t has its terminals connected to the anodes of the tube and its center point to conductor at leading to the negative terminal 01 resistor it. Secondary winding at is connected to the filament of tube 3t and the latter is connected through a choke coll til to conductor it connected to the positive terminal of resistor 3d. The terminals of the choke coil db are connected to conductor 30 by the usual filter condensers id. Secondary winding M is utilized to supply current to the cathode heaters 0f the remaining electron tubes of the system, to which reference will be had shortly. It should be understood that while an electronic power supply has been illustrated, a battery could also be used to supply the requisite voltage across resistor i l.

The energy impulse supplying means includes a condenser and relay means in the form of an electron tube 52 (preferably of the 6L 6G type) having inits output circuit the primary winding 5d of a transformer dd, the secondary winding 58 of which is connected to the junction of conductors tit and it and to the fence wire it through a blocking condenser 60 (of a value of about .25 mi). The condenser 50 is connected across the major portion MA of resistor ll so that it is normally charged to a voltage resistor 3d and the cathode to a morepositive portion of that resistor. A portion MB of the resistor is thus effectively in series with the cathode of the tube. The grid is connected to the negative terminal through a conductor 66, a resistor t8 (having a value 01' about 100,000 ohms), and a conductor ill. The cathode is connected to the resistor 34 through a conductor 12 having an adjustable connection relative to resistor 34.

,The tube E52 includes, in addition, a screen grid l t connected to the plate in conventional manner.

The conductivity of tube 52 is controlled in response to a control voltage resulting from contact between the fence and an animal to produce acurrentimpulse through transformer winding and an energy impulse through the fence wire and the body of the animal contacting the wire. The control voltage is obtained by placing a resistor in the low voltage circuit and utilizing the change in voltage drop thereacross when an animal contacts the fence. In the instant case the low voltage normally applied to the fence is the voltage of slightly less than 300 volts appearing across conductors 40 and I2, the former of which is connected to ground and the latter of which is connected to the fence wire through a resistor I4 (having a value of about 100,000ohms) and conductor 16. The resistor 14 is utilized, not only inthe production of the control voltage but it also serves to limit the leakage current normally flowing from the fence to ground. Inasmuch as the resistor 14 is connected in circuit with the fence wire and ground, it may be seen that whenever the fence is contacted by a. terminal there is an increase in current flowing through the resistor 14 and a resulting increased voltage drop which makes the voltage of the fence end of resistor 14 more positive.

A selected portion of the control voltage is applied to relay means comprising the amplifier 24 through a condenser 18 (having a value of about .01 mi.) and a selected portion of resistor 80 (having a value of about 250,000 ohms) which serves as a "volume control. One terminal of resistor 80 is connected to the condenser 18 and the other to conductor 72. A portion of the voltage drop across resistor 80 is applied to the ampliiier through an adjustable contact 82 providing a sensitivity control, a selector switch 84, provided for a purpose to be set forth in greater detail hereinafter, and a resistor (having a value of about 50,000 ohms). The resistor 00 is provided to act as a safeguard in the event resistor 80 is cut out entirely.

The condenser 78 has a value such that slow changes in current flow through resistor I4, and therefore slow changes in voltage drop thereacross, will not be applied to the amplifier to produce an energy impulse. This construction thus prevents the apparatus from producing an energy impulse in response to slow or slight variations in resistance between the fence wire and ground, as might be caused by dampness and showers and by branches contacting the fence. Furthermore, the normal biasing of the tube 52 .to cutoff, as heretofore mentioned, precludes the possibility of the tube being rendered conductive when an animal disengages itself from the fence and produces a control impulse of opposite polarity to that produced upon contact. This is an advantage in that a shocking impulse is applied to the fence circuit only when an animal engages the fence.

The amplifier 24 may take various forms, and the one illustrated is of the two-stage resistance coupled type. A single duplicate section high gain 1 tube 90 (preferably of the 680'! type) is used. The first section includes a cathode 92, a control grid 94. and a plate 96. The second section includes a cathode 98, a grid I00 and a plate I02. The two cathodes are connected together andto conductor I2 through a self-biasing resistor I04 (having a value of about 2,000 ohms) which is bypassed by a condenser I 08 (having a value of about 10 mf.). Plates 96 and I02 are connected 'to the positive supply line 40 through resistors I00 and 0, respectively. I

The,control voltage obtained from across resistor I4 is applied to the grid 84 of the first tube section through a circuit including the previously referred to condenser 10 and resistors 80 and. The control voltage is amplified by the first section and supplied to the grid I00 of the second initial high .tion of tube through a coupling condenser H6 (having a value of about .01 mf. or somewhat larger)v and the previously referred to resistor 68 which also constitutes a coupling resistor.

When an animal contacts the fence, there is thus produced a control impulse which is amplified and applied to the grid of tube 52 to render the latter conductive so that the condenser 50 discharges through it. The discharge current flows through the primary 54 of transformer 56, thereby inductively to apply an energy impulse to the fence wire. In accordance with another feature of the present invention, the first impulse is reapplied to the amplifier and tube 52 to render the actual energy impulse supplied through the fence and ammal substantially independent of contact resistance between the animal and the wire. It may be noted that when the first voltage impulse is applied to fence wire H, the voltage of that wire -is changed and the secondary winding 58 is so connected to the ground and fence that the voltage impulse produces a flow of current through resistor 14 in a direction to render the fence end of the resistor more positive; i. e., the current flow is the same as when the animal first contacted the Y fence. The conductivity of tube 52 is thereby quickly increased to some value determined by which of the circuit elements saturates properly designed apparatus the various circuits may be so arranged that they all saturate at more or less the same time, although in an apparatus of the character described herein it is probably the first triode section of tube 90 that saturates first.

The two impulses occur so rapidly that they are in effect a single impulsel This impulse may produce a peak voltage across secondary winding 58 (when this winding is open circuited) of several thousand volts, perhaps as much as 7,000 volts. In order to prevent this high voltage from being applied to the grid 94 of tube 90, a cold cathode gas discharge tube I20 is connected across the grid and conductor 12. This tube is normally nonconductive, but when the voltage reaches some predetermined high value, say, of about 90 volts in the instant. embodiment, the tube becomes conduotive and thus limits the voltage.

The current impulse fiowing through the tube 52and transformer winding 54 is supplied by the condenser 50 and by the main power supply 22. In the illustrated embodiment where the resistor 34 has a value of about 50,000 ohms, the condenser and resistor both supply power for producing the energy impulse,- but if the value of resistor 34 is increased to about 1 megohm, then the condenser supplies most of the power. In both cases the condenser supplies the power for producing the energy or peaked portion of the impulse. After the initial impulse the current decreases rapidly to a safe minimum value because of a reduction in the control voltage applied to the am lifier and because the grid 04 of the first section of 1 the amplifier is made less positive with respect to the cathode. This results because of two factors, one being-a decrease in the voltag of the impulse and the second being the result of the flow of discharge current through the portion 343 of resistor 34 which is in series with the cathode 04 of the tube 52. The fiow of current through the efame resistor portion 343 makes the cathodes or the tube 90 more positive relative to the grids, thereby reducing in effect the positive potential of the grids relative to the cathodes.

The apparatus of the present invention may also be arranged to apply periodic impulses to the fence wire upon operation of the selector switch 84 to its uppermost position'wherein the resistor 86 is connected to the Junction of condenser ll-ti and resistor 50 through conductor 022. Thi in effect amounts to adjusting the volume control to increase the volume. The gain of the amplifier is then increased to so high a value that slight changes cause pulses to be produced in much the same manner as motorboating is produced in amplifiers. Periodic impulses can also be produced by decreasing the negative grid bias on tube 52 whereby that tube can be rendered conductive by the application of smaller control voltages thereto.

When the apparatus is conditioned for the production of periodic impulses it will also produce described above, 1. e., by the production of a con trol voltage appearing acrossresistor El i.

- The periodicity of the impulses may be adjusted by varying the value of resistance included in resistor portion 3 23, which varies the grid bias of tube 52 and also by varying the size of condenser.

- power supply 22, the positive terminal of which is connected to ground and the negative terminal of which is connected to the fence wire it through conductor it and the control resistor it.

When an animal contacts the fence the current flow through resistor lid is increased, thereby to provide a control voltage which is amplified to render the tube tit conductive and to produce an energy impulsewhich is reapplied to the amplifier to saturate the systemand quickly render tube 52 conductive enough so that the condenser 50 may discharge therethrough and through the primary winding of transformer 55. The flow of current through the primary winding of the transformer inductively produces a brief flow of high voltage current through the animal in contact with the fence, thereby to produce the requisite electric shock to deter the animal from going through the fence. This impulse is of short duration and quickly decreases to a safe value, at which it remains as long as the animal is in contactwith the fence. If the animal leaves the fence, then after a time interval determined primarily by the size of condenser b ll, the apparatus is ready to produce another impulse. Noshock ing impulse, however, is applied to the fence circuit when an animal leaves or disengages itself from the fence because of the heretofore referred to biasing of tube 52 to cutoff.

The apparatus will also produce a further impulse if a second animal comes into contact with the fence after the first has been in contact with the fence for a time interval long enough to enable the condenser 5% to be recharged. When a further impulse upon contact, in the manner the second animal conacts the fence .thefiow of current through resistor 54 is again increased to render th amplifier effective to make the tube 52 more conductive in the manner heretofore described. The occurrence of the shocking impulse substantially immediately upon contact is of advantage in conditioning the animals to remain away from the fence.

If it is desired to apply periodic impulses to the fence, the selector switch 8A is moved upwardly to complete a circuit to conductor (I22. This periodic application of impulses to the fence may be advantageously used in training the animals.

The sensitivity of operation of the apparatus may be adjusted by movement of the adjustable contact 82. This is an advantage in that the apparatus may be readily adjusted to provide the requisite shocking impulse under various atmospheric conditions under which the leakage resistanceto ground and the contact resistance between the animal and ground may vary between relatively wide limits. It is preferred that the sensitivity adjustment be such that the shocking impulse will be produced with a contact and leakage resistances of 50,000 ohms or upon a contact and leakage resistances of 25,000 ohms.

The discharge tube [1269 not only serves to limit the voltage applied to the amplifier tube to a safe value, but it also serves as an indicator of the operation of the apparatus. Each time an impulse is applied to the fence the tube is rendered conductive to indicate the application of the impulse. The tube also provides lightning protection as it breaks down and prevents the application of high voltages to the amplifier, etc.

The embodiment of the invention illustrated in Fig. 2 is in many respects similar to that of the first embodiment. However, there are some differences. In the first place, the control voltage is so connected to the fence that the fence wirei l is maintained at a positive potential, and in the second place the impulse producing circuit is substantially independent of the control circuit. The maintenance of the fence wire at a positive potential results in a marked decrease in the leakage current because the leakage resistance to ground is considerably greater when the wire is made positive than when the wire is made negative. It appears that there is present a, definite polarity effect making the leakage resistance considerably higher when the wire is positive. It appears further that this polarity effect results from the contact of the wire with vegetation and thatthe leakage resistance increases after the connection of the voltage to the wire, and that this increase is present, however, only when the wire is made positive with respect to ground.

'Thus by polarizing the fence wire positively by the control voltage, it is possible to secure efiec- .tive operation of the apparatus when other controllers may be inoperative because of low leakage resistance to ground.

Referring now to Fig. 2, it may be noted that the fence charging apparatus is supplied with power by a full wave rectifier indicated generally by the reference character H2 and including'a tube i3 3 (which may be of the 6X5GT type).

The rectified direct current output appears across the conductors i536 and it, the latter of which is the negativ line and is connected to ground.

The positive control voltage is applied to the fence wire through a filter resistor M0 (which may have a value of 25,000 ohms), a conductor M2, and a control resistor Wt (which may have a value of 100,000 ohms) corresponding to the conresistor I88 (which ma have a value condenser also acts trol resistor 14 of the previously described embodiment. A filter condenser I48 is connected across conductors I42 and I88. As heretofore indicated, the maintenance of the fence wire at a positive voltage increases the leakage resistance from the wire to ground and thus also decreases the leakage current.

The apparatus also include relay means in the form of a control and amplifying means indicated generally by the reference character I48. This means includes a tube i80 similar to the tube 80. The cathodes I02 and I84 of the two sections of the tube are connected to conductor I88 through of about 600 ohms) shunted by a condenser I88 (having a value of about microfarads). The plates I80 and I82 are connected to conductor I42 through .resistors I84 and I 88, respectively (each having a value of about 100,000 ohms). The grid I88 of the second tube is connected to plate I80 through a coupling condenser I10 (having a value of about .02 microfarad) and it is also connected to conductor I38 through resistor I12 (having a value of about 100,000 ohms).

A selected portion of the control voltage appearing across resistor I 44 when-an animal contacts the fence isapplied to the grid I14 of the first section of tube I80. The connected by a conductor I18 to a resistor I18 to provide a sensitivity a value of about 250,000 ohms). One terminal of the resistor I18 is connected to conductor I38 by the conductor I 80, and the other terminal is connected to the fence wire through a resistor I82 (having a value of about 100,000 ohms), a condenser 184 (having a value of about .01 microfarad), and conductor I88. The condenser serves to prevent operation of the amplifier to produce energy impulses unless the change in current fiow through the resistor is quite rapid, thereby to prevent the production of an energy impulse in response to slow variations in resistance between the fence and ground as might be caused by dampness, showers, and the like.

In order to prevent injury to the apparatus as by the application of excessive voltages to the grid I14 of tube I50, the resistor I18 is shunted by' a protecting neon lamp I88 which, like the lamp I20 of the proceeding embodiment, breaks down at a voltage of about 80 volts. This tube also provides lightning protection. 1

The impulse producing means of the present embodiment includes a condenser I80 (having a value of about 2 microfarads), a gas tube I 82 (which maybe of the 631P1 type), and the primary winding I84 of a transformer I88. The arrangement is such that-when the tube I82 is rendered conductive the condenser I88 discharges through the tube and through the primary winding I84 of the transformer. The plate I88 of the gas tube is connected to one terminal of primary winding I84, the other terminal of which is connected to condenser I80 through conductor 200. The other terminal of condenser I80 is connected to conductor I88. The condenser is also shunted by a resistor 202 (about 470,000

ohms), utilized in the instant embodiment to decrease somewhat the voltage across' the condenser and to render the operation more stable. The as a filter condenser for the plate voltage supply. The separate plate voltage supply for the tube I82 and the connection of the condenser I80 7 operation of the apparatus because the impulse producing means is more independent of the amgrid is adjustablycontrol (the resistor has in this supply improves the second section of where, as here, a

- across-conductors I4 and 1 plifier and there is less tendency to oscillate. The p e producing tube I82 and condenser I are both connected to the power supply through a conductor 204 and a filter resistor 208 (having a value of about 25,000 ohms) connected to the conductor I38.

The tube I82 is rendered conductive in response to the control voltage produced when an animal contacts the fence. The control voltage i amplifled by the tube I 80 and the amplified voltage is utilized to render the ducing a voltagedifi'erence between

grids

208 and 208 of tube I82. The grid 208 is coupled to the tube I50 by the coupling condenser 2l0 (having a value of about .02 microfarad) and the coupling resistor value of about 400,000 ohms) and grid 208 is connected to the cathode 2I4. The cathode 2I4 of tube 182 is connected to conductor I38 by conductor 2l8. The voltage difierence between grids 288 and 208 is obtained by making grid 208 more negative when the animal contacts the fence, the more negative voltage resulting from the particular polarization, location of resistor I 44 and the nature of the amplifying means used. This voltage difference may be of the order of 60 volts plate voltage of about 300 volts is used. Ifdeslred, the tube could be rendered conductive by making the grid 208 more positive.

The shocking wire by the secondary winding 2I8 of transformer l 88 which is connected directly across conductors I4 and I38 through a blocking condenser 220.

Indication of operation of the apparatus to produce an impulse is provided by a lamp 222 similar to lamp I88 connected across conductors I4 and I88 by a resistor 224. I

In order readily to test the operation of the apparatus there is provided a manually operated pushbutton switch 228 adapted to close a circuit I38 through a. resistor 228, thereby to simulate conditions obtaining when an animal comes into contact with the fence. If the apparatus is operating properly an impulse is produced and the lam 222 glows to indicate the application of the shocking impulse to the fence.

To place the apparatus into operation, it is, necessary only to insert the plug connector I2 to a suitable source of alternating current and to close the power switch I8. The transformer I32 is thus energized to render the rectifier tube operative and likewise to activate the tube I 50. The rectifier charges the condenser I 80 in a short time interval determined by the values of

resistors

208 and 202. A positive control potential is also applied to the fence wire I4 to obtain the advantageous increased leakage resistance and decreased leakage current heretofore referred to.

When an animal comes into contact with the fence the flow of current through the control resistor I44 increases. grid I14 of tube I50 is This control impulse is 2| 2 (having a rendered more negative. amplified and utilized to render the grid 208 of tube I82 more negative, with the result thatthe tube becomes conductive as a result of the voltage difference across

grids

208 and 208. The condenser I80 thereupon discharges through the tube and through the primary winding I84. The current flowing through the winding induces a voltage in the secondary winding 2I8 which in turn provides the shocking impulse applied to the animal through the fence wire I4 and the ground connection I38.

In the instant embodiment the arrangement tube conductive by proimpulse is applied to the fence with the result that the' these having values of 11 is such that the circuit saturates immediately, 1. e., there is no reapplication of the impulse voltage to the amplifier. This advantageous result is obtained by utilizing the gas tube I02 which becomes fully conductive immediately.

The apparatus produces but a single impulse upon contact, and successive impulses cannot be.

produced in any event except at time intervals predetermined by the values of

resistors

202 and 206.

Each time the apparatus operates the indicator lamp 222 is lighted to provide an indication of the operation. This indicator lamp also lights up when the switch 220 is closed, provided, of course, that the apparatus is functioning properly.

The sensitivity of the apparatus may be readily varied by adjustment of the contact M6 to apply more or less of the voltage across resistor M8 to the grid I14 of tube I50. 1

The embodiment of the invention illustrated in Fig. 3 is quite similar to that of Fig. 2. It differs primarily in that a single lamp 2% isutilized as a combined indicator and protective lamp. The positions of resistor I02 and condenser H84 have also been transposed, and the lamp 240 is connected in parallel with the series connected condenser I84 and resistor H0. The lamp becomes conductive when an dicate operation and it becomes conductive also in the event lightning strikes the fence to protect the equipment. Other difierences reside in the change in values of resistors Md and E82, about .5 megohm. and .7 megohm, respectively. In addition, resistor 2&2 of Fig. 2, which was in parallel with condenser I90, has been eliminated, the voltage across the condenser in this case being proper for the particular tube and plate voltage supply.

The operation of the embodiment of Fig. 3 is like that of Fig. 2, so that further description thereof at this point is not deemed necessary.

In many cases the fence wires are located in proximity to high tension power lines and are likely to pick up stray voltages and it is another feature of the present invention to provide an apparatus that will not be operated by stray volt-= ages of a magnitude normally encountered in ractice. Preferably the apparatus is construct ed so that it will not operate even though the 60-cycle pickup is on the order of 10 volts.

Ordinarily, the high tension wires transmit 60-cycle alternating current. In order to prevent the apparatus from being operated by stray 60-cycle voltages, the amplifiers, in those embodiments in which amplifiers are used, are constructed and arranged to attenuate power fre-- quencies and amplify best frequencies in the or der of the pulse rate, which may be in the order of those produced by contact with the wire,

which may be predominantly in the order of about 4,000 cycles per second (the pulse duration being of the order of 200 microseconds). Thus in the embodiment of Figures 1, 2 and 3, the amplifiers are supplied through condensers and utilize coupling condensers attenuating 60-cycle current, i. e., the condensers are made smaller so as to pass the desired high frequencies and attenuate the lower frequencies. In the embodiment of Figure l, condensers H8, H2 and H6 and their associated resistors are designed to provide this attenuation; and in the embodiments of Figures 2 and 3, the condensers E86, 6710 and H are designed for the same purpose.

From the foregoing detailed description of the impulse is produced to inpresent invention it may be note that the principles thereof may take various forms. It is contemplated that the invention is not to be limited to the precise constructions disclosed but is to include within its scope all such modifications and variations coming within the scope of the appended claims.

Having described my invention, what I claim as new and desire to obtain by Letters Patent of the United States is:

1. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, means including normally inoperative energy impulse supplying means adapted to be coupled to the fence wire and adapted when rendered operative to supply an energy impulse to the fence wire, voltage supplying means adapted to be coupled to the fence wire for applying a control voltage to the wire, means adapted to be coupled to the fence wire for producing a change in current flow when an animal contacts the wire, and change responsive relay means coupled to said last mentioned means and controlled in response to a change in current flow occurring'above a predetermined rate upon con- "tact between the wire and the body of an animal and controlling said impulse supplying means for rendering the latter operative.

2. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, normally inoperative energy impulse supplying means including a condenser and a transformer having a primary winding adapted inductively to be coupled to the fence wire and through which the condenser is adapted to be discharged, voltage supplying means adapted to be coupled to the fence wire for applying a control voltage to the fence wire, and means including an electron tube in circuit with the primary winding and condenser, means adapted to be coupled to the fence wire for producing a control voltage in response to a change in current flow in the fence circuit and means in cluding a capacitor of predetermined capacity coupling the tube to said last mentioned means for rendering the tube conductive in response to a change in current flow occurring above a predetermined rate upon contact between the wire and the body of an animal for discharging said condenser through said primary winding and tube.

3. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire,

including in combination, means including nor mally inoperative energy impulse supplying means adapted to be coupled to the fence wire and relay means controlling said supply means for supplying an energy impulse to the fence wire, means including voltage supplying means. adapted to be coupled to the fence wire for applying a control voltage to the fence wire to produce a change in current flow upon contact between the animal and wire, means operable in response to said change in current flow for producing a control voltage and means including amplifier means adapted to be coupled to the fence wire and amplifying the effect of the change coupled to said control voltage producingmeans and to said relay means for rendering the latter operable to supply an energy impulse upon the occurrence of said control voltage.

4. Apparatus for energizing a fencejcornp "sing a conductive wire adapted to be'placed'inl'circuit with the body of an animal contacting the wire, including in combination, means including normally inoperative energy impulse supplying means coupled to the fence wire adapted when rendered operative to supply an energy impulse to the fence wire, voltage supplying means coupled to the fence wire for applying a control voltage to the fence wire, means coupled to the fence wire for producing a control impulse when an animal contacts the fence, means coupled to said last mentioned means for amplifying said impulse,

and means coupled to said amplifying means con trolled by said amplified impulse and controlling said impulse supplying means to supply an energy impulse to said fence wire which is reamplified and utilized to supply an energy impulse to the fence wire which is independent of the contact resistance between the wire and animal.

5. Apparatus for energizing a fence comprising a-conductive wire adapted to be placed in circuit with the body of an animal contacting the wire,

vincludin in combination, normally inoperative energy impulse supplying means adapted to be coupled to the fence wire including an electron tube and a condenser dischargeable through the tube adapted when rendered operative to supply an energy impulse to the wire, voltage supplying means adapted to be coupled to the wire for applying a control voltage to the fence wire, change responsive means adapted "to be coupled to the fence wire for producing a control impulse when an animal contacts the fence, means coupled to said last mentioned means for amplifying said impulse, and means coupling said amplifying means to said tube for rendering said tube conductive in response to said amplified impulse, thereby to supply an energy impulse to said fence wire which is independent of the contact resistance between the fence wire and animal.

'6. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, means including energy impulse supplying means adapted to be coupled to the fence wire including a condenser and an electron tube adapted when rendered conductive to supply an energy impulse to the fence wire, voltage supplying means adapted to be coupled to the fence wire for applying a control voltage to the fence wire, means also adapted to be coupled to the fence wire for producing a control impulse when an animal contacts the wire, and impulse operated means supplied with said control impulse and controlling the conductivity of said tube to effect the discharge of said condenser.

7. An electric fence charging apparatus including in combination, means coupled to the fence wire including relay meansoperable to supply an energy impulse to the fence wire, and amplifier means'having an input circuit coupled to the fence wire and an output circuit coupled to the relay for operating the relay, the gain of the amplifier being sufficiently high to cause the amplifier to oscillate at a low frequency thereby to effect periodic operation of said relay means and the periodic supply of energy impulses to the fence wire.

8. An electric fence charging apparatus including in combination, means coupled to the fence wire including relay means operable to supply an energy impulse to the fence wire, an amplifier having input and output circuits, means coupling the fence wire to the amplifier input circuit, the amplifier having its output circuit coupled to said relay means and a gain sufficient to set the amfence wire, voltage supplying means coupled to the fence wire for applying a control voltage to the wire, and means including means coupling the input circuit of the amplifier to the fence wire operable in response to a change in current flow occurring upon contact between an animal and the fence for supplying a control impulse which is applied to the amplifier to effect operation of said relay to operate said impulse producing means. 9. An electric fence charging apparatus including in combination, means coupled to the fence wire including relay means operable to supply an energy impulse to the fence, an amplifier having input and output circuits, means connecting the fence wire to the amplifier input circuit, said means including a potentiometer resistance coupled to the fence wire and a two position selector switch adapted to apply different portions of the voltage drop across the potentiometer to the amplifier input circuit, voltage supplying means coupled to the fence wire for applying a control voltage to the wire, means coupled to the fence wire and resistance operable .in response to a change in current flow occurring upon contact between an animal and the fence wire for supplying a control impulse to the input circuit of said amplifier for operating said relay means, the fence w'ire, potentiometer resistance, selector switch and amplifier gain being so constructed and arranged that in one position of the switch the relay means is operated to produce energy impulses only in response to said control impulses and in the otherv position of said switch the amplifier is set into low frequency oscillation and the relay means is operated also to produce periodic energy impulses. .10. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, means including energy impulse supplying means adapted to be coupled to the fence wire and relay means controlling said supply means for supplying an energy impulse to the fence wire, voltage supplying means adapted to be coupled to the fence wire for applying a control voltage to the fence wire, means adapted to be coupled to the fence wire for producing a control voltage in response to a change in current flow when an animal contacts the wire, amplifier means coupled to said last mentionedmeans for controlling said relay means controlled in response to said control voltage for rendering said relay means effective to supply an energy impulse, and means for limiting the voltage applied to the amplifier means from said fence wire.

11. Apparatus for energizing afence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, means including normally inoperative energy impulse supplying means coupled to the fence wire and relay means controlling said supplying means for applying an energy impulse to the fence wire, voltage supplying means coupled to the fence wire for applying a control voltage to the fence wire, other relay means controlling said first mentioned relay means and coupled to the fence wire and controlled in response to a change in current flow occurring upon contact between the wire, and the body of an animal for rendering said first mentioned relay means efiective to supply an energy impulse, and means for varying the sensitivity of said other relay means in response to changes in said current flow.

12. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, means including normally inoperative energy impulse supplying means coupled to the fence wire and relay means controlling said supplying means for applying an energy impulse to .the fence wire, voltage supplying means coupled to the fence wire for applying a control voltage to the fence wire, amplifier means coupling the fence wire to said relay means and controlled in response to a change in current flow occurring upon contact between the wire and the body of ananimal for rendering said relay means effective to supply an energy impulse, and means in circuit with the amplifier means for adjusting the input to said amplifier means.

13. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, energy impulse supplying means adapted to be coupled to the fence wire to supply an energy impulse to the wire, means adapted to be coupled to the fence wire for producing a change in an electrical characteristic occurring-at a rate substantially in excess of 60 cycles per second when an animal contacts the wire, and means having a predetermined frequency characteristic coupled to said last mentioned means controlled in response to changes in an electrical characteristic of the fence wire occurring at a rate substantially in. excess of 60 cycles per second and controlling said first mentioned means for rendering said first mentioned means effective to supply an energy impulse to said wire. a

14. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, energy impulse supplying means adapted to be coupled to the fence wire and to supply an energy impulse to the fence wire, means associated with the fence wire for producing a control impulse having a duration of the order of 200 microseconds when P an animal contacts the wire, and means including an amplifier constructed and arranged to amplify frequencies on the order of that of said control impulse and coupled to said control impulse and energy impulse supplying means for rendering the latter effective to supply an energy impulse to the fence wire.

15. Apparatus for energizing a fence comprising a conductive wire adapted to be laced in circuit with the body of an animal contacting the wire, including in combination, energy impulse supplying means coupled to the fence wire adapted to supply an energy impulse to the wire, means including a low voltage control means coupled to the fence wire and controlling said first mentioned means and controlled in response to contact between the wire and the body of an animal for rendering said first mentioned means efiective to supply an energy impulse through the fence circuit, and means coupled to said low voltage control means for limiting the application of high voltages such as might be induced by lightning upon said low voltage means. a

16. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, means includ ing normally inoperative high voltage energy impulse supplying means coupled to the fence wire adapted when rendered operative to supply an energy impulse to the fence wire, means including an amplifier controlling said last mentioned means and having its input connected to the fence wire and operable upon contact between the wire and the body of an animal for rendering said impulse supplying means operative, and means including a normally nonconductive gas discharge tube connected across the input of the amplifier for indicating operation of the apparatus and for limiting the voltage input to said amplifier.

1'7. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, a low voltage source-of power and a. pair of branch circuits leading therefrom, normally inoperative energy impulse supplying means coupled to the fence wire including a condenser connected to and normally charged from first of said branch circuits, a transformer having aprimary winding connected to and through which the condenser is adapted to be discharged and which is inductively connected to thefence for supplying a high voltage energy impulse to the fence wire and an electron tube in series with said primary winding for effecting the discharge of said condenser through said winding and the tube, means connecting the second branch circuit to the wire for applying a control voltage to the wire, means coupled to the fence wire for producing a control voltage when an animal contacts the wire, and amplifier means coupled to said last mentioned means and controlling said tube and operable upon a change in current flow in the fence circuit for rendering said tube conductive to discharge said condenser through said primary winding and tube.

18. Apparatusfor energizing a fence comprising a conductive wire' adapted to be placed in circuit with the body of an animal contacting the wire,' including in combination, a low voltage source of power and a pair of branch circuits leading therefrom, normally inoperative energy impulse'supplying means including a condenser connected to and normally charged from a first of said branch circuits, a transformer having a primary winding connected to the condenser through which the condenser is adapted to be discharged and which is inductively connected to the fence wire for supplying a high voltage energy impulse to the fence wire and means for effecting the discharge of said condenser, means including a circuit including a resistor for applying a control voltage to the fence circuit from the second of said branch circuits, means including an amplifier connected to said resistor circuit operable upon a change in current flow through said resistor foroperating said discharge effecting means,1the input of said amplifier being coupled to the resistor circuit through a series connected resistor and a condenser, and a gas discharge tube shunting said resistor and condenser.

19. Apparatus for energizing a fence comprising a conductive wire adapted to be grounded electrically through the body of an animal contacting the wire, including in combination, voltage supplying means adapted to be coupled to the fence wire for normally applying a voltage to the fence wire, energy impulse supplying means adapted to be coupled to the wire adapted to sup- 17 ply an energy impulse to the fence wire, and change responsive means adapted to be coupled to the wire and controlled in response to change in current flow resulting upon contact between the wire and the bodies of animals and controlling said last mentioned means for rendering the latter effective when a change in current flow occurs upon contact to supply successive impulses of energy to said wire in response to succes ive contacts between the fence wire and animals.

20. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the bod y of an animal contacting the wire, including in combination, a voltage source, a condenser, means connecting the condenser to the voltage source for chargingsaid condenser from said source, means including an electron tube connected to the condenser and through which the condenser is adapted to discharge for producing a single impulse energy discharge through the fence circuit and the body of an animal when the animal contacts the wire, means adapted to be coupled to the fence wire for producing a change in an electrical characteristic when an animal contacts the fence wire, and means adapted to be coupled to said last mentioned means and controlling the conductivity of said tube in response to changes in said electri cal characteristic occurring at a predetermined rate and rendering said tube conductive in response to said change to supply an energy impulse.

21. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, a first voltage source, means including a resistor adapted to connect said voltage source to said wire, a second voltage source, a condenser connected to said second voltage source to be charged thereby, means adapted to be coupled to the fence wire and including an electron tube connected to said second source and across said condenser for effecting the discharge of said condenser to provide a shocking impulse across the fence circuit, and

mean coupled to said resistor and tube and controlled in response to the voltage drop across said resistor for controlling the conductivity of the tube.

22. Apparatus for energizing a fence comprising a conductive wire adapted. to be placed in circuit with the body of an animal contacting the wire, incuding in combination, energy impulse supplying means adapted to be coupled to th fence wire including a normally nonconductive electron tube for supplying an energy impulse the wire, including in combination, energy impuls supplying means coupled to the fence wire including a. normally nonconductive grid controlled electron tube for supplying an energy impulse to the fence wire, means including a resistor coupled to the fence'wire and a condenser coupling the resistor to the grid of the tube for rendering .the grid potential of said tube more positive in response to a change in an electrical characteristic of th fence circuit occurring at a predetermined rate for rendering said tube conductive in response to a change occurring upon contact between the wire and an animal, and means normally biasing the tube to cutoff for preventing said tube from being rendered conductive in response to a change occurring upon disengagement of the animal from'the wire.

24. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, energy impulse supplying means adapted to be coupled to the fence wire and adapted to supply ,a single shock of brief duration to the fence wire, means also adapted to be coupled to the fence circuit for producing an electrical change when an animal contacts the fence wire, and electrical change responsive means coupled to said last mentioned means controlled in response to said electrical to the fence wire, means adapted to be coupled to the fence wire for producing a change in an electrical characteristic when an animal contacts the wire, and means including change responsive mean having a predetermined change response.

coupling the tube to said last mentioned means and controlling the conductivity of said tube in response to a change in an electrical characteristic of the fence wire occurring at a predetermined rate for rendering said tube conductive in response to a change occurring upon contact bechange occurring upon contact between the wire and the body of an animal and controlling said first mentioned means for rendering the latter operative to supply a single shock of brief'duration.

25. Apparatus for energizing a fence comprising a conductive wire adapted to be placed in circuit with the body of an animal contacting the wire, including in combination, energy impulse supplying means adapted to be coupled to the fence wire and adapted to supply a single energy impulse to the fence wire, means adapted to be coupled to the fence wire for producing an electrical change when an animal contacts the fence wire, and electrical characteristic change responsive means coupled to said last mentioned means effective in response to changes in an electrical characteristic, occurring at a predetermined rate, resulting upon contact between the wire and the body of an animal, and controlling said first mentioned means for rendering the latter operative in response to such a change to supply a single energy impulse.

WILLIAM F. FAGEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,172,050 Mayberry Sept. 5, 1939 2,258,669 Agne'w et a1 Oct. 14, 1941 2,333,224 Agnew Nov. 2, 1943 2,198,715 Willis Apr. 30, 1940 1,956,416 Elder Apr. 24, 1934 1,738,299 Kille Dec. 3, 1929 2,139,489 Cockrell Dec. 6, 1938 FOREIGN PATENTS Number Country Date 109,051 British Nov. 8, 1939 OTHER REFERENCES Agricultural Engineering, page 400, Fig. 3, Nov. 1941.