CA1170708A - Pulse generator control circuit for fence electrification - Google Patents
Pulse generator control circuit for fence electrificationInfo
- Publication number
- CA1170708A CA1170708A CA000372977A CA372977A CA1170708A CA 1170708 A CA1170708 A CA 1170708A CA 000372977 A CA000372977 A CA 000372977A CA 372977 A CA372977 A CA 372977A CA 1170708 A CA1170708 A CA 1170708A
- Authority
- CA
- Canada
- Prior art keywords
- fence
- resonant circuit
- thyristor
- charging capacitor
- pulse
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000003990 capacitor Substances 0.000 claims abstract description 63
- 238000007600 charging Methods 0.000 claims abstract description 52
- 230000010355 oscillation Effects 0.000 claims description 21
- 238000004804 winding Methods 0.000 claims description 17
- 239000004020 conductor Substances 0.000 claims description 11
- 230000001052 transient effect Effects 0.000 claims description 8
- 230000001939 inductive effect Effects 0.000 claims description 4
- 238000011084 recovery Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 3
- 230000004044 response Effects 0.000 claims description 3
- 230000001131 transforming effect Effects 0.000 claims description 3
- 229920000136 polysorbate Polymers 0.000 claims description 2
- 238000010304 firing Methods 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 4
- 230000035939 shock Effects 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000013016 damping Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004118 muscle contraction Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- QHGVXILFMXYDRS-UHFFFAOYSA-N pyraclofos Chemical compound C1=C(OP(=O)(OCC)SCCC)C=NN1C1=CC=C(Cl)C=C1 QHGVXILFMXYDRS-UHFFFAOYSA-N 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05C—ELECTRIC CIRCUITS OR APPARATUS SPECIALLY DESIGNED FOR USE IN EQUIPMENT FOR KILLING, STUNNING, OR GUIDING LIVING BEINGS
- H05C1/00—Circuits or apparatus for generating electric shock effects
- H05C1/04—Circuits or apparatus for generating electric shock effects providing pulse voltages
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Insects & Arthropods (AREA)
- Catching Or Destruction (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
- Saccharide Compounds (AREA)
- Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
- Housing For Livestock And Birds (AREA)
- Generation Of Surge Voltage And Current (AREA)
Abstract
ABSTRACT
Disclosed is a pulse generator for generating pulses for an electric fence and having a pulse transformer of which the inductances and leakage inductances form, together with an electrical charging capacitor connected to the primary side and an electrical capacitor connected to the secondary side, for example a fence capacitance, a coupled series and parallel oscillator cir-cuit. The charging capacitor is discharged by triggering a thyristor in the primary side. The thyristor is blocked at a predeterminable and reproducible point in time as soon as sufficient energy has been drawn from the charging capacitor for a desired pulse to be applied to the electric fence. The inven-tion reduces energy losses and provides increased shock effect as compared to prior art arrangements.
Disclosed is a pulse generator for generating pulses for an electric fence and having a pulse transformer of which the inductances and leakage inductances form, together with an electrical charging capacitor connected to the primary side and an electrical capacitor connected to the secondary side, for example a fence capacitance, a coupled series and parallel oscillator cir-cuit. The charging capacitor is discharged by triggering a thyristor in the primary side. The thyristor is blocked at a predeterminable and reproducible point in time as soon as sufficient energy has been drawn from the charging capacitor for a desired pulse to be applied to the electric fence. The inven-tion reduces energy losses and provides increased shock effect as compared to prior art arrangements.
Description
1~7070~
The invention relates to a pulse generator, in particular for generating pulses for an electric fence and having a pulse transformer of which the inductances and leakage inductances form, together Witll an electrical charging capacitor connected to the primary side and an electrical capacitor connected to the secondary side, for example a fence capacitance, a coupled series and parallel oscillator circuit, and having incorporated into the parallel switching circuit of the primary winding of the pulse transformer and charging capacitor a thyristor controlled by a pulse timer to fire in a pre-determined time sequence or a transistor with remot~ control facility to act as a switch, the charging capacitor being constantly connected to a charging current circuit and the capacitance of -the charging capaci~or being substant-ially greater than the capacitance of the capacitor connected to the secondary side.
Where pulse generators of this type are concerned, the pulse to be generated and applied for example to an electric fence originates as a result of the electrical oscillation initiated upon closure of the parallel current circuit of a primary winding and charging capacitor and transformation of this oscillation to a high voltage in the pulse transformer. Prior art units of this type are so dimensioned that the thyristor is blocked by the negative half-wave of that oscillation which is determined by parallel inductance in the coupled series and parallel oscillating circuit and the capacitance of the charging capacitor. This means that the thyristor is blocked by the negative half-wave of the current in the second periodic oscillation, i.e. the main oscillation. Since however, in the coupled series and parallel oscillating circuit, the voltage of the oscillation leads the current of the oscillation by ~, at the moment of blocking of the thyristor, the charging capacitor is already charged with a polarity reversed to what it was originally. For the : . . . .
~ ' . ' ' ' " ';
l ~070a next pulse from the current source, therefore, it must be discharged and charged with reverse polarity.
German Offenlegungsschrift No. 27 33 145 has already proposec~ that the switching element in the primary circuit, i.e. the parallel current cir-cuit of charging capacitor ancl primary winding of the pulse transformer, be opened when the series capacitance has been charged up to, or close to, the upper peak value of the transient voltage. In practice, however, it has been demonstrated that this method of controlling the switching element is very sensitive and can only be carried out with difficulty.
In contrast, it is the object of the invention to provide an improved circuit arrangement in which the switching element in the parallel current circuit of a charging capacitor and primary winding oP a pulse trans-former is reliably blocked at solne predeterminable and reproducible point in time or opens this parallel current circuit as soon as sufficient ene:rgy has been drawn rom the charging capacitor for a desired pulse, for example a pulse which is to be applied to an electric fence.
According to the invention, this problem is resolved in that the thyristor in respect of its recovery time and the pulse timer in respect of ;~ the width of the trigger pulse 4~r, analogous with the recovery time of the thyristor and the width of the trigger pulse, the phase positions of the signals given to the transistor by the rcmotc control element, are so attuned to the electrical values of leakage inductance, effective capacitance on the secondary side and ohmic series resistance as determined by the electrical magnitudes of the pulse transformer and of the connected capacitors provided in the coupled series-parallel circuit and by the first sine-wave current arising upon closure of the parallel circuit of charging capacitor and primary winding of the pulse transformer, that the first negative half-wave (between -' , 1 l7070~
~'~ 1 and 2-" 1) of the sine-wave current blocks the thyristor or ~he transistor and the triggering pulse which renders the thyristor or the transistor conduc-tive, is shorter than the first positive half-wave (between 0 and li`l) of this sine-wave current, this attuning being however so contrived that a damping occasioned by cutting in a previously established reslstance on the secondary side suppresses the negative half-wave tbetween~jl l and 2'i~`l) o~ the current of the first sinusoidal oscillation sufficiently for it no longer to block the thyristor or the transistor.
The invention provides two essential advantages: avoidance of lQ losses and increased shock effect in electric fences. Both results constitute substantial improvements in electric fence technology.
In a particularly advantageous embodiment of the invention, it ls possible to connect in parallel with the secondary winding of the pulse trans-former a fixed capacitor whlch ls parallel wlth the Eence capacitance, one or a plurality of diodes belng incorporated into one or both connectlng lines be-tween this flxed capacitor and the fence capacitance.
In the event of a transistor belng used as the switch, the remote control of the transistor may be equipped with means of attunement to the length or capacitance of the electric fence.
Thus, in accordance with a broad aspect of the invention, there is provided, in an electric fence,in combination:
a) a fence conductor, b) circuitry including a transforming, voltage-multiplying in-ductive device, said circuitry having terminals connected respectively to the fence conductor and to a ground, c) said circuitry comprising a parallel resonant circuit having a primary coil containing inductance and ohmic resistance of said device, a charging capacitor and a controllable switching device all connected in series, ' ~ .` , ' ;; ' . ' ' '' ' `
.
:~ `
`-` 1 17~70~
said switching device having a control electrode to which control signals may beapplied, d) said circuitry comprising a series resonant circuit whlch includes said charging capacitor in series connection with a fence capacitance occurring between said fence conductor and ground, leakage inductance of said device, resistance of said inductive device and conductor, and said controllable switching device, e) means connecting sald charging capacitor for continuous energiæation from a voltage source whereby the switching device, in response to repetitious impul-ses applied to its control electrode, can repeatedly switch on to allow current to discharge the charging capacitor and to flow within the parallel resonant cir-cuit, thereby to produce voltages and currents in the series resonant circuit, f) said series resonant circuit having a predetermined resonant ~requency which is so related to circuit characteristics associated with SRiCI ~Iwi~chlng device that the second halE-wave of a transient current in the serie~l resonant circuit occurring when the switching device is switched on will result in the switching device turning off to interrupt the current discharging of said charg-ing capacitor, wherein an animal contacting said fence conductor presents a dis-: charge resistance which damps said transient current so that the switching device ls not turned off and said charging capacitor discharges through said animal.
~ 20 Embodiments of the invention will be described in greater detail :~ ~ hereinafter with reference to the accompanying drawings~ in which:
Figure l shows the principle of the circuitry in the pulse gen-erator according to the invention which can be fed alternatively from a direct:
current voltage source, or from an alternating current voltage source, :: Figure 2 shows the palse generator according to Figure 1 with the ~: equivalent substitute circuit~diagram of:its pulse transformer;
Figure 3 shows a modified embodiment of the pulse generator according ' . ' -3a-~: :
~ ` ' 1 17070~
to Figure 1 in which the electric fence is coupled via a diode and wherein a fixed capacitor is applied parallel with the secondary winding of the pulse transformer, c~nd Figure ~ shows the principle of the time-related pattern of the cur-rent through the thyristor during a pulse process in the case of equipment representing the state of the art.
In the view in Figure 1, ~1 and Wz are the primary winding and the secondary winding of a pulse transformer T with the associated inductances Ll and L2. Lsl and Ls2 are the relevant leakage inductances which usually amount to a few percent of the particular main inductance concerned. Rl and R2 are the ohmic winding and line resistances. Cl is a - preferably large - charging capacitor which - as illustrated - is connected to the primary winding Wl via the thyristor Th. The charging capacitor CL is charged to a voltage UL, :ln fact via an upstream series-connected diode Dl, from a direct current voLtage source which may for example be a DC-DC converter G2 or an alt~rnating current voltage source Gl equipped with a rectifier.
i - Connected in parallel with the secondary winding of thè pulse trans-former Tr is a capacitance Cz which is preferably intended to represent the .
capacitance of a fence wire in respect of the earth. This capacitance Cz can however, in another application, also be a fixed capacitor or the like. Rz isan ohmic resistance which is for example cut in when an animal touches the fence wire, energy being consumed via this resistance ~or animal's body).
T is a E~ se known pulse timer which preferably at intervals of r, approximately 1 second to 2 seconds emits a brief trigger pulse to the grid of the thyristor Th and renders it conductive, the timer preferably being fed directly from the relevant voltage source.
Flgure 2 shows the electrical layout diagram corresuonding to ~he ~, : ~ ` -` ' ' :` ~
~ ~7~70~
pulse generator according to Figure 1. L is the equivalent replacement induc-tance o the pulse transformer, L is the equivalent inductance of the leakage inductance and R is the equivalent resistance. The pulse transformer has as a rule a transformation ratio in which W2 is greater than Wl. All values in the equivalent circuit diagram relate either to the primary side or to the seconcl-ary side.
Let it be assumed that the charging capacitor Cl is charged to volt-age Ul. A trigger pulse renders the thyristor Th conductive. As a result, the charging capacitor Cl is switched to the pulse transformer. The equivalent inductance L is large in comparison with the equivalent leakage inductance Ls, so that the impedance of the path L , R, C is substantially smaller than -that of the path via L. As Figure 4 shows) inltially a damped sine-wave Currellt flows, determined by the angular magnitudes of the first path, and has an angular frequency of ~1 By reason of the small values of Ls ;in comparison with L and o Cz in comparison with Cl, the requency of this first oscilla-tion is high. When this oscillation, known as a buildlng-up transient oscillation, has elapsed~ the current merges into a second oscillation which is determined by the capacitance of the charging capacitor C1J the equivalent inductance L of the pulse transformer and the equivalent resistance R. The angular frequency ~2 of this second oscillation is therefore substantially smaller than the angular frequency ~1 of the first oscillation.
Before the thyristor Th becomes conductive, a definite amount of electrical energy is stored in the charging capacitor Cl (~2 Cl U12). If the thyristGr Th is triggered and is blocked only as of the moment in time ~2' as occurs according to the state of the art, then the energy swings between the charging capacitor Cl and the equivalent inductance L of the pulse transformer.
The charging capacitor Cl discharges fully and there is built up in the induc-, -1 l7~70a tance L an ecluivalent magnetic energy ~ LI2) which in turn flows back to the charging capacitor Cl as capacitive energy - but with reversed polarity. At point in time ~2' the charging capacitor - with deduction of the losses - is charged again with reverse polarity.~ The current through the thyristor Th is now negative and the thyristor blocks. By reason of the now reversed polarity of the energy in the charging capacitor Cl, the diode Dl is now conductive ancl the energy flows out and becomes equalised in the upstream power supply, e.g.
in the mains. The energy is lost and does not come back. The charging capacitor Cl must now be charged again. This process is repeated.
In the case of a well-insulated fence - when only the fence capaci-tance C~ is cut in - only a small part of the energy (in R) is consumed in the pulse generator and in the connected fence. The main part of the energy is lost due to reversal of the polarity and the resultant dischar~e o the charg-ing capacikor Cl via the power supply, I~` a fence discharge -resistance Rz ~for example contact with an animal) is cut in~ then the energy flows out of the charging capacitor Cl fully or partially, according to the slze of the resistance R~ directly into this consumer and is here usefully converted ~for example into a shock effect).
At the point in time ~2~ this process has already elapsed. No or only very little energy flows back to the charging capacitor Cl.
As a rule, an electric fence is well insulated. Contact with an animal occurs only very rarely and therefore has no noticeable influence on the overall energy balance of the electric fence equipment.
The energy taken from the current source per pulse must be written off as lost energy in the case of conventional units. In the case of equip-ment operated from the electricity supply mains, this is tolerable, because ;~ this amount of energy is only very small even in the case of powerful units.
:0~` : :
:: : -: , - -. . .
:- ~ ~ .. . .... ..
-: -: ~ ' : ': ` :
s - ~ :
1 ~7070a This waste of energy does ho~ever become important in the case of battery-operated equipment, which represents as much as 80% o~ the equipment in prac-tical use. Such units are operated from special dry batteries which are relatively expensive. As stated above, this expensive energy is almost com-pletely converted into pure loss energy.
A basic remedy is provided according to the invention if the thyristor is blocked already at the negative half-wave of the first sinusoidal operation (~1 to 2~1). By this point in time, only as much energy will have flowed out of the charging capacitor Cl as is required to charge the fence capacitance Cz. The fence capacitance C is as a rule small in comparison with the capacitance of the charging capacitor Cl, so that the major part of the energy remains unchanged in the charging capacitor Cl.
According to the invention, therefore, the values of leakage induc-tance Ls, equivalent resistance R and the secondary-side capacitanceJ i.e. a fixed capacitor C2 connected to the fence capacitance Cz or in parallel wi~h the secondary winding W2 of the pulse transormerl as well as the recovery time of the thyristor Th are so selected that the thyristor is blocked by the negative half-wave of the first oscillation ~1 to 2~1). At the same time, though, the trigger pulse must have elapsed already at ~1 so that the trigger pulse does not keep the thyristor open. The process of discharging the charg-ing capacitor Cl is interrupted again. Then, only as much energy is taken from the charging capacitor Cl as is required to charge the secondary-side capacitancel whether it be a parallel-connected fixed capacitor C2 or the fence capacitance Cz. The energy given off thereby by the charging capacitor Cl is additionally supplied by the upstream energy source.
In the event oE animal contact,;a discharge resistance R lS cut in in parallel with the fence capacitance Cz. This leads to a marked damping of ', ~ ':
~ ~ -; :
~: , ' - --' ' ' . ,. :
ll~07~a the first oscillation, the second half-wave of the first oscillation between ~1 and 2~1 becoming substantially smaller or no longer appearing. The thyristor Th is now no longer blocked. The energy of the charging capacitor Cl now discharges itself fully via the connected resistance ~z or the body of the animal, this energy or a part thereof generating an effect of pain due to muscle contraction.
In the case of the above-explained attuning and construction of the circuit arrangement according to Figures 1 and 2, in accordance with the invention, normally the charge applied to the fence capacitance C is dis-charged again via the upstream inductance, so that also this amount of energy is lost. If in the case of very long electric fences the fence capacitance C
nevertheless assumes a considerable level, then in a modified embodin~ent shown in Figure 3 the flow-back of this energy can be prevented by incorporating a diode D2. In this case, for practical purposes, there is no further energy loss. ~lowever, in this case it is necessary to provide a fixed capacitor C2 so that the first sinusoidal oscillation can form. The capacitance of this fixed capacitor C2 may be small in comparison with the capacitance of the charging capacitor Cl so that also the losses which are unavoidable can be kept s-lall by this fi~ed capacitor C2.
,~ .
:
:: , - , ' :
The invention relates to a pulse generator, in particular for generating pulses for an electric fence and having a pulse transformer of which the inductances and leakage inductances form, together Witll an electrical charging capacitor connected to the primary side and an electrical capacitor connected to the secondary side, for example a fence capacitance, a coupled series and parallel oscillator circuit, and having incorporated into the parallel switching circuit of the primary winding of the pulse transformer and charging capacitor a thyristor controlled by a pulse timer to fire in a pre-determined time sequence or a transistor with remot~ control facility to act as a switch, the charging capacitor being constantly connected to a charging current circuit and the capacitance of -the charging capaci~or being substant-ially greater than the capacitance of the capacitor connected to the secondary side.
Where pulse generators of this type are concerned, the pulse to be generated and applied for example to an electric fence originates as a result of the electrical oscillation initiated upon closure of the parallel current circuit of a primary winding and charging capacitor and transformation of this oscillation to a high voltage in the pulse transformer. Prior art units of this type are so dimensioned that the thyristor is blocked by the negative half-wave of that oscillation which is determined by parallel inductance in the coupled series and parallel oscillating circuit and the capacitance of the charging capacitor. This means that the thyristor is blocked by the negative half-wave of the current in the second periodic oscillation, i.e. the main oscillation. Since however, in the coupled series and parallel oscillating circuit, the voltage of the oscillation leads the current of the oscillation by ~, at the moment of blocking of the thyristor, the charging capacitor is already charged with a polarity reversed to what it was originally. For the : . . . .
~ ' . ' ' ' " ';
l ~070a next pulse from the current source, therefore, it must be discharged and charged with reverse polarity.
German Offenlegungsschrift No. 27 33 145 has already proposec~ that the switching element in the primary circuit, i.e. the parallel current cir-cuit of charging capacitor ancl primary winding of the pulse transformer, be opened when the series capacitance has been charged up to, or close to, the upper peak value of the transient voltage. In practice, however, it has been demonstrated that this method of controlling the switching element is very sensitive and can only be carried out with difficulty.
In contrast, it is the object of the invention to provide an improved circuit arrangement in which the switching element in the parallel current circuit of a charging capacitor and primary winding oP a pulse trans-former is reliably blocked at solne predeterminable and reproducible point in time or opens this parallel current circuit as soon as sufficient ene:rgy has been drawn rom the charging capacitor for a desired pulse, for example a pulse which is to be applied to an electric fence.
According to the invention, this problem is resolved in that the thyristor in respect of its recovery time and the pulse timer in respect of ;~ the width of the trigger pulse 4~r, analogous with the recovery time of the thyristor and the width of the trigger pulse, the phase positions of the signals given to the transistor by the rcmotc control element, are so attuned to the electrical values of leakage inductance, effective capacitance on the secondary side and ohmic series resistance as determined by the electrical magnitudes of the pulse transformer and of the connected capacitors provided in the coupled series-parallel circuit and by the first sine-wave current arising upon closure of the parallel circuit of charging capacitor and primary winding of the pulse transformer, that the first negative half-wave (between -' , 1 l7070~
~'~ 1 and 2-" 1) of the sine-wave current blocks the thyristor or ~he transistor and the triggering pulse which renders the thyristor or the transistor conduc-tive, is shorter than the first positive half-wave (between 0 and li`l) of this sine-wave current, this attuning being however so contrived that a damping occasioned by cutting in a previously established reslstance on the secondary side suppresses the negative half-wave tbetween~jl l and 2'i~`l) o~ the current of the first sinusoidal oscillation sufficiently for it no longer to block the thyristor or the transistor.
The invention provides two essential advantages: avoidance of lQ losses and increased shock effect in electric fences. Both results constitute substantial improvements in electric fence technology.
In a particularly advantageous embodiment of the invention, it ls possible to connect in parallel with the secondary winding of the pulse trans-former a fixed capacitor whlch ls parallel wlth the Eence capacitance, one or a plurality of diodes belng incorporated into one or both connectlng lines be-tween this flxed capacitor and the fence capacitance.
In the event of a transistor belng used as the switch, the remote control of the transistor may be equipped with means of attunement to the length or capacitance of the electric fence.
Thus, in accordance with a broad aspect of the invention, there is provided, in an electric fence,in combination:
a) a fence conductor, b) circuitry including a transforming, voltage-multiplying in-ductive device, said circuitry having terminals connected respectively to the fence conductor and to a ground, c) said circuitry comprising a parallel resonant circuit having a primary coil containing inductance and ohmic resistance of said device, a charging capacitor and a controllable switching device all connected in series, ' ~ .` , ' ;; ' . ' ' '' ' `
.
:~ `
`-` 1 17~70~
said switching device having a control electrode to which control signals may beapplied, d) said circuitry comprising a series resonant circuit whlch includes said charging capacitor in series connection with a fence capacitance occurring between said fence conductor and ground, leakage inductance of said device, resistance of said inductive device and conductor, and said controllable switching device, e) means connecting sald charging capacitor for continuous energiæation from a voltage source whereby the switching device, in response to repetitious impul-ses applied to its control electrode, can repeatedly switch on to allow current to discharge the charging capacitor and to flow within the parallel resonant cir-cuit, thereby to produce voltages and currents in the series resonant circuit, f) said series resonant circuit having a predetermined resonant ~requency which is so related to circuit characteristics associated with SRiCI ~Iwi~chlng device that the second halE-wave of a transient current in the serie~l resonant circuit occurring when the switching device is switched on will result in the switching device turning off to interrupt the current discharging of said charg-ing capacitor, wherein an animal contacting said fence conductor presents a dis-: charge resistance which damps said transient current so that the switching device ls not turned off and said charging capacitor discharges through said animal.
~ 20 Embodiments of the invention will be described in greater detail :~ ~ hereinafter with reference to the accompanying drawings~ in which:
Figure l shows the principle of the circuitry in the pulse gen-erator according to the invention which can be fed alternatively from a direct:
current voltage source, or from an alternating current voltage source, :: Figure 2 shows the palse generator according to Figure 1 with the ~: equivalent substitute circuit~diagram of:its pulse transformer;
Figure 3 shows a modified embodiment of the pulse generator according ' . ' -3a-~: :
~ ` ' 1 17070~
to Figure 1 in which the electric fence is coupled via a diode and wherein a fixed capacitor is applied parallel with the secondary winding of the pulse transformer, c~nd Figure ~ shows the principle of the time-related pattern of the cur-rent through the thyristor during a pulse process in the case of equipment representing the state of the art.
In the view in Figure 1, ~1 and Wz are the primary winding and the secondary winding of a pulse transformer T with the associated inductances Ll and L2. Lsl and Ls2 are the relevant leakage inductances which usually amount to a few percent of the particular main inductance concerned. Rl and R2 are the ohmic winding and line resistances. Cl is a - preferably large - charging capacitor which - as illustrated - is connected to the primary winding Wl via the thyristor Th. The charging capacitor CL is charged to a voltage UL, :ln fact via an upstream series-connected diode Dl, from a direct current voLtage source which may for example be a DC-DC converter G2 or an alt~rnating current voltage source Gl equipped with a rectifier.
i - Connected in parallel with the secondary winding of thè pulse trans-former Tr is a capacitance Cz which is preferably intended to represent the .
capacitance of a fence wire in respect of the earth. This capacitance Cz can however, in another application, also be a fixed capacitor or the like. Rz isan ohmic resistance which is for example cut in when an animal touches the fence wire, energy being consumed via this resistance ~or animal's body).
T is a E~ se known pulse timer which preferably at intervals of r, approximately 1 second to 2 seconds emits a brief trigger pulse to the grid of the thyristor Th and renders it conductive, the timer preferably being fed directly from the relevant voltage source.
Flgure 2 shows the electrical layout diagram corresuonding to ~he ~, : ~ ` -` ' ' :` ~
~ ~7~70~
pulse generator according to Figure 1. L is the equivalent replacement induc-tance o the pulse transformer, L is the equivalent inductance of the leakage inductance and R is the equivalent resistance. The pulse transformer has as a rule a transformation ratio in which W2 is greater than Wl. All values in the equivalent circuit diagram relate either to the primary side or to the seconcl-ary side.
Let it be assumed that the charging capacitor Cl is charged to volt-age Ul. A trigger pulse renders the thyristor Th conductive. As a result, the charging capacitor Cl is switched to the pulse transformer. The equivalent inductance L is large in comparison with the equivalent leakage inductance Ls, so that the impedance of the path L , R, C is substantially smaller than -that of the path via L. As Figure 4 shows) inltially a damped sine-wave Currellt flows, determined by the angular magnitudes of the first path, and has an angular frequency of ~1 By reason of the small values of Ls ;in comparison with L and o Cz in comparison with Cl, the requency of this first oscilla-tion is high. When this oscillation, known as a buildlng-up transient oscillation, has elapsed~ the current merges into a second oscillation which is determined by the capacitance of the charging capacitor C1J the equivalent inductance L of the pulse transformer and the equivalent resistance R. The angular frequency ~2 of this second oscillation is therefore substantially smaller than the angular frequency ~1 of the first oscillation.
Before the thyristor Th becomes conductive, a definite amount of electrical energy is stored in the charging capacitor Cl (~2 Cl U12). If the thyristGr Th is triggered and is blocked only as of the moment in time ~2' as occurs according to the state of the art, then the energy swings between the charging capacitor Cl and the equivalent inductance L of the pulse transformer.
The charging capacitor Cl discharges fully and there is built up in the induc-, -1 l7~70a tance L an ecluivalent magnetic energy ~ LI2) which in turn flows back to the charging capacitor Cl as capacitive energy - but with reversed polarity. At point in time ~2' the charging capacitor - with deduction of the losses - is charged again with reverse polarity.~ The current through the thyristor Th is now negative and the thyristor blocks. By reason of the now reversed polarity of the energy in the charging capacitor Cl, the diode Dl is now conductive ancl the energy flows out and becomes equalised in the upstream power supply, e.g.
in the mains. The energy is lost and does not come back. The charging capacitor Cl must now be charged again. This process is repeated.
In the case of a well-insulated fence - when only the fence capaci-tance C~ is cut in - only a small part of the energy (in R) is consumed in the pulse generator and in the connected fence. The main part of the energy is lost due to reversal of the polarity and the resultant dischar~e o the charg-ing capacikor Cl via the power supply, I~` a fence discharge -resistance Rz ~for example contact with an animal) is cut in~ then the energy flows out of the charging capacitor Cl fully or partially, according to the slze of the resistance R~ directly into this consumer and is here usefully converted ~for example into a shock effect).
At the point in time ~2~ this process has already elapsed. No or only very little energy flows back to the charging capacitor Cl.
As a rule, an electric fence is well insulated. Contact with an animal occurs only very rarely and therefore has no noticeable influence on the overall energy balance of the electric fence equipment.
The energy taken from the current source per pulse must be written off as lost energy in the case of conventional units. In the case of equip-ment operated from the electricity supply mains, this is tolerable, because ;~ this amount of energy is only very small even in the case of powerful units.
:0~` : :
:: : -: , - -. . .
:- ~ ~ .. . .... ..
-: -: ~ ' : ': ` :
s - ~ :
1 ~7070a This waste of energy does ho~ever become important in the case of battery-operated equipment, which represents as much as 80% o~ the equipment in prac-tical use. Such units are operated from special dry batteries which are relatively expensive. As stated above, this expensive energy is almost com-pletely converted into pure loss energy.
A basic remedy is provided according to the invention if the thyristor is blocked already at the negative half-wave of the first sinusoidal operation (~1 to 2~1). By this point in time, only as much energy will have flowed out of the charging capacitor Cl as is required to charge the fence capacitance Cz. The fence capacitance C is as a rule small in comparison with the capacitance of the charging capacitor Cl, so that the major part of the energy remains unchanged in the charging capacitor Cl.
According to the invention, therefore, the values of leakage induc-tance Ls, equivalent resistance R and the secondary-side capacitanceJ i.e. a fixed capacitor C2 connected to the fence capacitance Cz or in parallel wi~h the secondary winding W2 of the pulse transormerl as well as the recovery time of the thyristor Th are so selected that the thyristor is blocked by the negative half-wave of the first oscillation ~1 to 2~1). At the same time, though, the trigger pulse must have elapsed already at ~1 so that the trigger pulse does not keep the thyristor open. The process of discharging the charg-ing capacitor Cl is interrupted again. Then, only as much energy is taken from the charging capacitor Cl as is required to charge the secondary-side capacitancel whether it be a parallel-connected fixed capacitor C2 or the fence capacitance Cz. The energy given off thereby by the charging capacitor Cl is additionally supplied by the upstream energy source.
In the event oE animal contact,;a discharge resistance R lS cut in in parallel with the fence capacitance Cz. This leads to a marked damping of ', ~ ':
~ ~ -; :
~: , ' - --' ' ' . ,. :
ll~07~a the first oscillation, the second half-wave of the first oscillation between ~1 and 2~1 becoming substantially smaller or no longer appearing. The thyristor Th is now no longer blocked. The energy of the charging capacitor Cl now discharges itself fully via the connected resistance ~z or the body of the animal, this energy or a part thereof generating an effect of pain due to muscle contraction.
In the case of the above-explained attuning and construction of the circuit arrangement according to Figures 1 and 2, in accordance with the invention, normally the charge applied to the fence capacitance C is dis-charged again via the upstream inductance, so that also this amount of energy is lost. If in the case of very long electric fences the fence capacitance C
nevertheless assumes a considerable level, then in a modified embodin~ent shown in Figure 3 the flow-back of this energy can be prevented by incorporating a diode D2. In this case, for practical purposes, there is no further energy loss. ~lowever, in this case it is necessary to provide a fixed capacitor C2 so that the first sinusoidal oscillation can form. The capacitance of this fixed capacitor C2 may be small in comparison with the capacitance of the charging capacitor Cl so that also the losses which are unavoidable can be kept s-lall by this fi~ed capacitor C2.
,~ .
:
:: , - , ' :
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an electric fence, in combination:
a) a fence conductor, b) circuitry including a transforming, voltage-multiplying inductive de-vice, said circuitry having terminals connected respectively to the fence con-ductor and to a ground, c) said circuitry comprising a parallel resonant circuit having a primary coil containing inductance and ohmic resistance of said device, a charging ca-pacitor and a controllable switching device all connected in series, said switch-ing device having a control electrode to which control signals may be applied, d) said circuitry comprising a series resonant circuit which includes said charging capacitor in series connection with a fence capacitance occurring be-tween said fence conductor and ground, leakage inductance of said device re-sistance of said inductive device and conductor, and said controllable switching device, e) means connecting said charging capacitor for continuous energization from a voltage source whereby the switching device, in response to repetitious impulses applied to its control electrode, can repeatedly switch on to allow current to discharge the charging capacitor and to flow within the parallel re-sonant circuit, thereby to produce voltages and currents in the series resonant circuit, f) said series resonant circuit having a predetermined resonant frequency which is so related to circuit characteristics associated with said switching device that the second half-wave of a transient current in the series resonant circuit occurring when the switching device is switched on will result in the switching device turning of to interrupt the current discharging of said charg-ing capacitor, wherein an animal contacting said fence conductor presents a dis-charge resistance which damps said transient current so that the switching device is not turned off and said charging capacitor discharges through said animal.
a) a fence conductor, b) circuitry including a transforming, voltage-multiplying inductive de-vice, said circuitry having terminals connected respectively to the fence con-ductor and to a ground, c) said circuitry comprising a parallel resonant circuit having a primary coil containing inductance and ohmic resistance of said device, a charging ca-pacitor and a controllable switching device all connected in series, said switch-ing device having a control electrode to which control signals may be applied, d) said circuitry comprising a series resonant circuit which includes said charging capacitor in series connection with a fence capacitance occurring be-tween said fence conductor and ground, leakage inductance of said device re-sistance of said inductive device and conductor, and said controllable switching device, e) means connecting said charging capacitor for continuous energization from a voltage source whereby the switching device, in response to repetitious impulses applied to its control electrode, can repeatedly switch on to allow current to discharge the charging capacitor and to flow within the parallel re-sonant circuit, thereby to produce voltages and currents in the series resonant circuit, f) said series resonant circuit having a predetermined resonant frequency which is so related to circuit characteristics associated with said switching device that the second half-wave of a transient current in the series resonant circuit occurring when the switching device is switched on will result in the switching device turning of to interrupt the current discharging of said charg-ing capacitor, wherein an animal contacting said fence conductor presents a dis-charge resistance which damps said transient current so that the switching device is not turned off and said charging capacitor discharges through said animal.
2. The invention as defined in claim 1 wherein said switching device is a thyristor and said circuit characteristics include the holding current and turn-off-time of the thyristor.
3. The invention as defined in claim 2, wherein the thyristor auto-matically blocks out the first negative half-wave of the transient current.
4. The invention as defined in claim 1, where the inductance in the series resonant circuit is substantially less than the value of the inductance in the parallel resonant circuit.
5. The invention as defined in claim 1, and further including a second capacitor which is connected between the ground and the terminal connect-ed to the fence wire.
6. The invention as defined in claim 5, wherein the second capacitor has a capacitance equivalent to an electric fence.
7. The invention as defined in claim 2, wherein:
a) the inductive device comprises a pulse transformer having primary and secondary windings, b) the inductance of said parallel resonant circuit includes the primary winding of the transformer, c) a pulse timer is connected to the thyristor to switch the latter on at fixed time intervals, d) said secondary winding of the transformer is connected to said fence conductor and ground, e) said pulse transformer has a smaller leakage inductance than its winding inductances, f) said parallel resonant circuit has an appreciably lower oscillation frequency than that of the series resonant circuit, g) said thyristor has holding current which is appreciably smaller than the initial discharge current of said charging capacitor, such initial discharge current building up to a sine-shaped positive half-wave in the series resonant circuit, h) said thyristor has a recovery time which is shorter than the oscillation frequency half-period in the series resonant circuit, i) said pulse timer has a pulse length in time of the firing pulse given by it to the thyristor, which is shorter than the said oscillation frequency half-period of the series resonant circuit,
a) the inductive device comprises a pulse transformer having primary and secondary windings, b) the inductance of said parallel resonant circuit includes the primary winding of the transformer, c) a pulse timer is connected to the thyristor to switch the latter on at fixed time intervals, d) said secondary winding of the transformer is connected to said fence conductor and ground, e) said pulse transformer has a smaller leakage inductance than its winding inductances, f) said parallel resonant circuit has an appreciably lower oscillation frequency than that of the series resonant circuit, g) said thyristor has holding current which is appreciably smaller than the initial discharge current of said charging capacitor, such initial discharge current building up to a sine-shaped positive half-wave in the series resonant circuit, h) said thyristor has a recovery time which is shorter than the oscillation frequency half-period in the series resonant circuit, i) said pulse timer has a pulse length in time of the firing pulse given by it to the thyristor, which is shorter than the said oscillation frequency half-period of the series resonant circuit,
8. The invention as defined in claim 1, wherein:
a) the means connecting the charging capacitor for continuous energization is exclusive of said transforming device.
a) the means connecting the charging capacitor for continuous energization is exclusive of said transforming device.
9. The invention as defined in claim 1, 4 or 5 wherein said control-lable switching device comprises a transistor and external control means for turning said transistor off in response to said second half-wave of a transient current in the series resonant circuit.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3009838A DE3009838C2 (en) | 1980-03-14 | 1980-03-14 | Pulse generator |
| DEP3009838.5 | 1980-03-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1170708A true CA1170708A (en) | 1984-07-10 |
Family
ID=6097223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000372977A Expired CA1170708A (en) | 1980-03-14 | 1981-03-13 | Pulse generator control circuit for fence electrification |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0036089B1 (en) |
| AT (1) | ATE10892T1 (en) |
| AU (1) | AU6834081A (en) |
| CA (1) | CA1170708A (en) |
| DE (2) | DE3009838C2 (en) |
| NZ (1) | NZ196469A (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IE55329B1 (en) * | 1984-02-22 | 1990-08-15 | David Reynolds Gray | A high voltage pulse generator |
| DE3437953A1 (en) * | 1984-10-17 | 1986-04-24 | AKO-Werke GmbH & Co KG, 7988 Wangen | Circuit arrangement for producing pulses for a pasture-fence apparatus |
| AU592155B2 (en) * | 1986-02-24 | 1990-01-04 | Gallagher Electronics Limited | Electric fence energiser |
| DE3727787A1 (en) * | 1987-08-20 | 1989-03-02 | Horizont Geraetewerk | GENERATOR FOR GENERATING ELECTRIC FENCE IMPULSES |
| DE3914888A1 (en) * | 1989-05-05 | 1990-11-15 | Texas Instruments Deutschland | CIRCUIT ARRANGEMENT FOR GENERATING A CONTROL SIGNAL DEPENDING ON THE APPEARANCE OF AN EXTREME VALUE OF A SINE VIBRATION AND APPLICATION OF SUCH A CIRCUIT ARRANGEMENT |
| US5126745A (en) * | 1989-05-05 | 1992-06-30 | Texas Instruments Deutschland Gmbh | Circuit arrangement for generating a control signal in dependence upon the occurrence of an extreme value of a sinusoidal oscillation and use of such a circuit arrangement |
| ES2048662B1 (en) * | 1992-07-30 | 1997-02-16 | Celaya Emparanza Galdos Sa | PERFECTED FENCING ELECTRIFYING DEVICE. |
| DE4327572C1 (en) * | 1993-08-17 | 1994-10-13 | Horizont Geraetewerk | Electrical fence apparatus |
| SE504979C2 (en) * | 1993-12-29 | 1997-06-09 | Alfa Laval Agri Ab | Device and method for determining the grounding of an electric fence |
| DE4405671C1 (en) * | 1994-02-23 | 1995-05-04 | Horizont Geraetewerk | Electric fence apparatus |
| FR2787964B1 (en) * | 1998-12-23 | 2001-03-23 | Lacme | FENCE ELECTRIFIER WITH LOW-MASS TRANSFORMER |
| DE102014101319B4 (en) | 2014-02-04 | 2016-01-07 | Gerhard Kleine | Electric fence pulse generator and electric fence |
| CN111398865B (en) * | 2020-04-17 | 2022-07-05 | 国网福建省电力有限公司 | Transient current-based transformer secondary circuit inspection method |
| CN112713798B (en) * | 2020-12-18 | 2021-12-03 | 华中科技大学 | Pulse power supply, GW-level power traveling wave magnetic field generation device and method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH477128A (en) * | 1968-03-14 | 1969-08-15 | Cie Generale D Electronique In | Pulse generator circuit |
| DE2733145C2 (en) * | 1977-07-22 | 1982-09-30 | Horizont Gerätewerk GmbH, 3540 Korbach | Electrical circuit arrangement for generating pulses for electric fence devices |
| DE2847993A1 (en) * | 1978-11-06 | 1980-05-22 | Horizont Geraetewerk | ELECTRIC FENCE |
-
1980
- 1980-03-14 DE DE3009838A patent/DE3009838C2/en not_active Expired
-
1981
- 1981-02-18 DE DE8181101145T patent/DE3167770D1/en not_active Expired
- 1981-02-18 AT AT81101145T patent/ATE10892T1/en active
- 1981-02-18 EP EP81101145A patent/EP0036089B1/en not_active Expired
- 1981-03-11 NZ NZ196469A patent/NZ196469A/en unknown
- 1981-03-13 AU AU68340/81A patent/AU6834081A/en not_active Abandoned
- 1981-03-13 CA CA000372977A patent/CA1170708A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3009838A1 (en) | 1981-09-24 |
| EP0036089B1 (en) | 1984-12-19 |
| ATE10892T1 (en) | 1985-01-15 |
| AU6834081A (en) | 1981-09-17 |
| DE3167770D1 (en) | 1985-01-31 |
| NZ196469A (en) | 1984-05-31 |
| DE3009838C2 (en) | 1982-09-23 |
| EP0036089A1 (en) | 1981-09-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1170708A (en) | Pulse generator control circuit for fence electrification | |
| EP0055903B1 (en) | An electrical power supply | |
| US5766124A (en) | Magnetic stimulator for neuro-muscular tissue | |
| EP0201876B1 (en) | Series resonant converter | |
| US4567424A (en) | Reactive power compensator with capacitor and capacitor discharge circuit | |
| AU567769B2 (en) | Minimization of harmonic contents for mains operated switching regulator. | |
| EP1360751A2 (en) | Battery charger circuit with low standby power dissipation | |
| CA1074406A (en) | High frequency power supply microwave oven | |
| US4396879A (en) | Coupled series and parallel resonant circuit, in particular for electric fence apparatus | |
| GB2298370A (en) | Magnetic stimulator with increased energy efficiency | |
| US4546304A (en) | Electronic device with choke inverter | |
| US4882663A (en) | MOSFET flyback converter | |
| CA2009805A1 (en) | Two-lead igniter for hid lamps | |
| EP0228226B1 (en) | An off-gate circuit for a gate-turn-off thyristor | |
| EP0230358A2 (en) | RF high voltage power supply | |
| EP0212817B1 (en) | Improvements in or relating to invertors | |
| EP0103473A1 (en) | Alternating power supply for highly inductive loads | |
| EP0589603B1 (en) | Exciter circuits and methods with protective measures for solid state switches | |
| AU592155B2 (en) | Electric fence energiser | |
| JPS6139860A (en) | One-transistor inverter | |
| RU2109394C1 (en) | Quasi-resonance constant voltage converter with switching- over under zero voltage | |
| SU1480009A2 (en) | Device for current protection of load | |
| RU2016668C1 (en) | Ultrasonic pulse generator | |
| SU1735958A1 (en) | Leakage-current protective device for ac lines | |
| SU1653068A1 (en) | Current protection for faults in ac networks |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |