The electric fence charger circuit presented here is basically a high voltage pulse generator. The super high voltage is derived from a commonly used automobile ignition coil.
An astable multivibrator is used to generate the required frequency to drive the ignition coil. Another astable is used to control the pulses supplied to the fence.
Protecting Crops with Fence Charger
If you have large agricultural fields and desperately need to protect the crops from uninvited guests like animals and possibly humans, then this electric fence charger device is just what you are looking for. Build and install it yourself.
An electric fence is an electrified high voltage barrier which produces painful shocks if physically touched or manipulated.
Thus such fencing basically function as deterrents for animals as well as human intruders and stop them from crossing the restricted boundary.
The present circuit of an electric fence charger is designed and tested by me and has proved sufficiently powerful for the application.
20 kV from the Sparks
The fence charger circuit is able to produce voltage pulses up to 20,000 volts, needless to say about the fatality rate involved with it.
However the pulses being intermittent, provides the subject with enough time to realize, recover and eject.
The generated pulse is so powerful that it can easily arc and fly-off between short distances of around a cm. so the fencing conductor needs to be separated adequately to avoid leakages through arcing and sparking. If not tackled, may drastically reduce the effectiveness of the unit.
Here the generation of high voltage is primarily carried out by an automobile ignition coil.
The winding ratios of an ignition coil are specifically designed and intended for creating high voltage arc between a two closely spaced conductors inside the ignition chamber to initiate the ignition process in vehicles.
Basically it’s just a step-up transformer, which is able to step-up an input applied voltage at its primary winding to monstrous levels at its output or the secondary winding.
WARNING: SOME POINTS OF THE CIRCUIT AND THE IGNITION COIL IS VERY DANGEROUS TO TOUCH WHEN POWERED. ESPECIALLY THE IGNITION COIL OUTPUT IS TOO LETHAL AND MAY EVEN CAUSE PARALYSIS. APPROPRIATE CAUTION IS STRICTLY RECOMMENDED. THE AUTHOR CANNOT BE HELD RESPONSIBLE FOR ANY MISHAP.
Let’s diagnose the proposed electric fence charger circuit more deeply.
Circuit Operation
In the CIRCUIT DIAGRAM we see that the entire circuit is basically comprised of four stages.
A DC oscillator stage,
An intermediate 12 to 230 volts step-up stage,
The voltage collector and firing stage and the super high voltage-booster stage.
TR1 and TR2 are two normal step-down transformers whose secondary windings are connected through SCR2. TR1 input primary winding may be selected as per the country specification.
However, TR2 primary should be rated at 230 volts.
IC 555 along with the associated components forms a normal astable multivibrator stage. The supply voltage to the circuit is derived from the secondary of TR1 itself.
The output from the astable is used to trigger the triac BT136 and the whole system, at a particular fixed intermittent rate as per the settings of P1.
During the ON periods, the triac connects the 12 volt AC from TR1 to the secondary of TR2 so that a 230 volt potential instantly becomes available at the other end of TR2.
This voltage is fed to the voltage-firing stage consisting of the SCR1 as the main active component along with a few diodes, resistor and the capacitor C4.
The fired voltage from SCR1 is dumped into the primary winding of the ignition coil, where it is instantly pulled to a massive 20,000 volts at its secondary winding. This voltage may be suitably terminated into the fencing.
The high voltage generated by this electric fence charger will need to be carefully applied across the whole length of the fence.
The two poles from the ignition coil connected to the fence wiring should be kept at least 2 inches apart.
The pillars of the fence should be ideally made of plastic or similar non conducting material, never use metal and not even wood (wood tend to absorb moisture and may give path to leakages).
Parts List for the explained electric fence charger circuit using SCR
- R4 = 1K, 1WATT = 1
- R5 = 100 OHMS, 1WATT = 1
- P1 = 27K PRESET = 1
- C4 = 105/400V PPC = 1
- ALL DIODES ARE 1N4007
- IC = 555 = 1
- TR1 = 0-12V/3Amp (120 or 230V) = 1
- TR2 = 0-12V/1Amp (120 or 230V) = 1
- THE SCR IS BT151 = 1
- THE TRIAC COULD BE ANY 1AMP/400V SUCH AS BT136 = 1
- TWO WHEELER IGNITION COIL SHOWN IN BLUE/RED COLOR = 1
The above concept can be also implemented using a BJT for the generating the triggering pulses for the transformer, as shown below
Please increase the TIP122 base resistor value to 10K for reducing increased dissipation from the transistor.
Adjust the 1M pot such the ON time of the IC 555 is much shorter than the OFF time, for reducing current consumption.
Video showing how an Ignition Coil could be applied for producing high voltage
Mini Fence Charger Circuit
The discussed fence charge above is relatively lager and stronger with its specifications. If you need something smaller, then the following mini fence charger circuit can be quite handy.
This may be used for driving away pests like cockroaches, slugs, worms, snails from any desired small premise such a terrace garden, balcony pot plants or simply for guarding food stuffs etc.
Circuit Operation
The referred circuit for the mini fence charger is shown below, it may be understood with the help of the following points:
The top part of the transformer winding basically delivers a reinforcement to the base of the transistor by means of C2 the T1 keeps being confined on to the conduction status until C2 charges completely, ending the latch and compelling the transistor to commence the conduction sequence afresh.
R1 that may be a 1K resistor is installed to restrict the base gain for T1 to secure inhibits whereas VR1 that could be a 22k preset could very well be tweaked for acquiring an effectively pulsating T1 rate.
C2 could be additionally fine tuned by attempting supplementary values until the maximum output is accomplished at the trafo output
Transformer Specs
The transformer could possibly be any iron-cored step down transformer (500mA) commonly employed in transformer version AC/DC power supply devices.
The output immediately across the transformer output may be at the evaluated secondary level, for instance whether it is a 220V secondary, in that case the output could possibly be anticipated to be with this levels.
The above degree could possibly be even more heightened or stepped up by means of the connected diode, capacitor charge pump set-up corresponding to cockroft-walton power generator system.
The set-up boosts the 220V level to scores of volts that could be compelled to spark across an accordingly deployed finish terminals of the charge pump circuit.
The above end high tension end terminals could be appropriately wired up across the whole length of the area which needs to be guarded from the bugs and for implementing the intended fencing charging operations.
The fence charger wires must be separated by some minimum distance so that the sparks do no keep flying of even in the absence of any external intrusion from the insects.
The explained mini fence charger circuit concept could be furthermore utilized in mosquito swatter bat purpose by swapping the iron cored transformer with a ferrite core counterpart.
Circuit Diagram
Using 4049 IC
Since the above fence charger can operate with a 12V battery, it is a suitable option for remote locations which may lack an access to AC power.
An oscillator circuit is constructed using two NOT gates N1 and N2 from a 4049 hex-inverting integrated circuit.
It has a PWM control feature using the pot R2. This can be used to fine-tune the output PWM to optimize output voltage and performance of the fence charging.
The MOSFET switches to ground whenever the positive pulse of the input at Q1's gate is available, connecting the primary winding of T1 across the 12 volt source.
When the MOSFET gate signal turns logic low, the current between Q1 and the transformer's primary is inhibited. This causes a high voltage pulse to be produced through T1's secondary winding.
This causes a high voltage in the order of around 20 kv to be generated at the output of T1. This output can be linked with the fence for the intended electrification.
Remember, T1 can be any automobile ignition coil. We recommend using a two-wheeler ignition coil.
How to Setup
- Setting potentiometer R2 to its half way is the easiest technique to optimize output arc and circuit performance.
- Next, hook up a DC current meter in series with the circuit and power supply positive.
- T1's output is then positioned approximately half an inch above the ground line of the circuit.
- Finally, R2 is adjusted for getting optimum output voltage spark and lowest current consumption by the circuit.
Fence charger circuit using SCR and Ignition Coil
Another simple design of a fence charger circuit is shown in the above figure. This circuit is designed to work with a 220V or a 120V AC input. So, this circuit can be used only in places where an AC outlet is available.
The SCR along with the capacitor C2 forms a capacitive discharge circuit, which works with a 310V DC input.
The 310 V from a 220 V RMS input or a 170 V from a 120 V RMS peak voltage inputs is achieved through two step down transformers connected back to back.
TR1 and TR2 transformers are two 0-12V/1A/220V/120V transformers configured with their 0-12V ends attached together.
This allows the circuit to get a high voltage low current peak DC supply input for the intended capacitive discharge operations.
When AC power is switched ON, the 220V or 120V from TR2 is converted into the required high voltage peak supply via the bridge rectifier and the capacitor C1.
The peak DC passes through R2 and the primary side of the ignition coil until C2 is fully charged. When charged fully it develops sufficient voltage to switch ON the zener diode D5.
D5 now conducts and fires the SCR. The SCR triggers ON and discharges C2 through it. This instantly causes the stored peak DC inside C2 to suddenly pass through the ignition coil primary.
This in turn causes an equivalent high voltage in the order 20 kV to be induced on the secondary side of the ignition coil. This 20 kV generated output is used for electrifying or charging the intended fences.
Simplest Fence Charge using Just a Couple of Transformers
If you have an access to a 220V AC or 120V AC mains input within reach, then perhaps the following simple transformer based AC fence energizer circuit could be used for the purpose, without incorporating any kind of complex circuitry.
The low current 220V side can be used to energize the fence.
To increase the output voltage to 500V AC you can use a 0-6V / 220 V transformer for the right hand side transformer.
Also if you wish to increase the current capacity of the output you can appropriately increase the Ampere rating of the two transformers.
The capacitor may be selected depending on the level of electric shock needed for the application.
Note: Although transformers are used for dropping the input current to significantly lower levels, still the output from this system may be large enough to kill any living thing if it happens to get stuck or entangled in the fence and is subjected to the current for a longer duration of time. Please build it AT YOUR OWN RISK.
Another simple Fence Charger Circuit using Transistors
Capacitor C1 undergoes charging via a constant current facilitated by transistor Q1.
Zener diode ZD1 maintains the base of Q3 at 13V, enabling conduction through D3 as the capacitor's charge reaches approximately 14.3V.
The conduction in Q3 delivers the gate trigger to SCR1. Subsequently, C1 discharges through the modified 6V winding in the transformer's primary.
This action generates a high-voltage pulse at the circuit's output, which is linked to the fence.
The discharge of C1 eliminates the gate drive to SCR1, allowing it to turn off as soon as the current reaches zero.
Diode D3 prevents excessive current flow through the base-emitter junction of Q3, safeguarding against reverse breakdown.
The current is limited to the diode's reverse leakage current, ensuring the safety of the transistor.
Under open circuit circumstances, SCR1 turns off independently as the transformer experiences slight ringing, diverting current from Q1 away from SCR1 and towards C1.
However, this automatic turn-off isn't assured when the circuit is loaded. To guarantee reliable turn-off of SCR1, C2 and Q2 temporarily interrupt the current from Q1, providing time for SCR1 to recover.
A resistor and neon bulb combination provides a visual confirmation of the fence charger circuit's operation, eliminating the necessity of touching the output terminals.
The lamp flashes with each pulse of the fence charger, indicating its functioning.
The T1 transformer can be any ordinary step-down transformer, connected in a reverse fashion, so that it steps-up the 6V to a 240V output.
Mark Heiman says
I would like to know if you can tell me how to build a DC electric fence energizer to protect my Bee Hive from bears? I have seen them using a car old style ignition coil, but do not know if they are powerful enough to discourage a bear. Thanks for any help.
Swagatam says
You can try the concepts presented in the above article. All the concepts are built using an automobile ignition coil, which are extremely powerful and can deter even an elephant.
doug says
my zareba fence charger has a 50uF+/-5%,.420 volt capacitor
is this the same type of capacitor used in a well pump?
I am a lIttle concerned about killing someone with electric fence but have had it for 40 years.
Swagatam says
Yes they can be the same capacitor, if the values printed are the same.
The last circuit in the article will not kill any animal. Still you can further reduce the capacitor values to 0.1uF/400V to make the shock milder.
John says
Dear Swagatam,thank you for your wishes,i almost feel beter and i’m waiting to pass the quarantine period. By the way, if you know can you suggest me any open source drawing program for prinding on boards? This will very helpful for me. Regards John.
Swagatam says
My wishes are always with you John, and we are glad to know about your speedy recovery.
I think if you Google the phrase “pcb drawing online”, you might come across a few good PCB design softwares
John says
Good morning from Greece, ( is 7:30 p.m is here!!! )I must first of all to thank you for your quick response to my questions, i appreciate that.But my problem is now that i’m in covid-19 quarantine to my house and i can’t do nothing!!! It it pass by the good way i will check out your changes. Thank you once more,John.
Swagatam says
You are most welcome, and wish you a happy and a quick recovery!!
John says
O.k. i will see about that, and i think maybe the cdi transformer is more heavy from two wheelsand not from chainsaw this may cause the Tip122 heating. Finally the project i need it for an area about 120 square meters with 3 lines coil ( to keep safe my bees ) will it cover it? What do you think ? Regards John.
Swagatam says
It will cover 120 sq meters if the CDI coil is a strong enough, you can try a car ignition coil and that should do the job…
The CDI coil and the transformer both will need to be heavy duty, and the TIP122 could be replaced with a TIP142.
John says
Good afternoon from Greece, well as i say before the base resistor it is already 10k and the transformer specs is 220v/12v/1A 50/60 hz. Do i need to replace TIP122 with one other stronger one( more than 5A)? What do you think? Yours John.
Swagatam says
Yes lower base resistance will allow higher current through the transformer and therefore brighter spark, but that will also cause the TIP122 to be hotter. If your DCc supply is 12V and the transformer is also 12V/1A then TIP122 should be OK with a large heatsink, however if you want to avoid the heatsink, then you can replace the TIP122 with TIP35 or TIP3055.
John Tsompanis says
Dear Swagatam good afternoon from Greece, my name is John and i’d like please to ask you for the fence cirquit this: i made the project and works fine exept the TIP122 is getting hot at once.The bace ressistor is 10k and ic555 between 6-7 22kwith 1M pot above.Any idea why this hapent? And finally you don’t give any prindable board diagramm and was for me very dificult to righ placing and connecting the parts together. Thank you for your answer replay, yours John. P.S. I place and a heatsink on.
Swagatam says
Dear John, try a 10k resistor at the base of TIP122, and you will have to put the transistor over a large heatsink.
By the way what is the transformer rating that you have used? If the transformer is big then the TIP122 will heat up more…try using a smaller transformer.
anushka prasanna says
can reduce the frequency to 1Hz
Swagatam says
yes you can.
Mohammad Alzoubi says
Dear Sir
If the area of the farm is about 50000 sq. meter, can this fence circuit be built with the same components so it can produce enough shock to avoid wild animals from entering the farm. If you have alternative circuit would you mind send it to my email. mes.mhz@gmail.com.
thank you for kind help.
Mohammad
Swagatam says
Hi Mohammad, I don’t think this can power the whole 5000 sq m area. However, you can install a single unit across every 200 sq meter distance to ensure the whole area is optimally secured.
ioannidis micheal says
how many meters of fence does it energize?
Swagatam says
20 meters
Mohammad says
Dear sir
Thank you for your kind response. Do you advice any product to protect the farm from wild pigs. Or if you have a certain circuit diagram so you can build it or I can build it to protect a fence of 800 meter. Please send me addresses if you have. Great thanks for you.
Best regards
Mohammad
Swagatam says
Mohammad, you can try siren sound method which will activate when an animal nears the fence. You can put many such sirens across different corners of the fence for the operation. Each module could be operated with battery, charged from a small individual solar panel.
Shubham says
Hello sir …how can I reduce output current to 9mA or less?
Swagatam says
Shubham, you can reduce the 105 capacitor to some lower value….
Michael says
Hi, can TV flyback transformer be used instead of car ignitor for distance of 2 feets squared, and if it can work, do you have a circuit diagram for it ?. Can tv flyback tx kill small animal like squirrel?
Swagatam says
Hi, it can be used and it will kill small animals so it’s not recommended. Even current from an ignition coil can kill small animals…I have this circuit in one of the electronic magazines that I will try to update it.
nadeem says
what is the best Jataka machine diagram can i get Gerber file on net
Swagatam says
can you please tell me for what purpose you need it! It’s required to know the power specification of the circuit
Pere Cardona says
Hello, I need your help
I have assembled an Electric fence energizer from a commercial kit and it works perfectly with an old car ignition coil.
https://www.pinterest.es/pin/311241024245287787/
https://www.pinterest.es/pin/311241024245287671/
The problem is that it ends with a 12V-7.2Ah / 20hr battery in less than 24 hours.
https://www.pinterest.es/pin/311241024245287726/
And it is the same battery that feeds another Electric fence energizer of industrial manufacture for 3 weeks.
Can any of you tell me how to reduce the consumption of this assembly?
Swagatam says
Hi, you can try increasing R2, R4 to 470 ohms, or upto 1K.
and decrease the value of the 33uF to 22uF or 10uF.
Please check the results and let me know!
Pere Cardona says
Hello, I appreciate your quick response.
Now I am traveling, when I return I will make the changes you recommend.
I will expose the results in this way
Swagatam says
OK, great!
Pedro Cardona Vives says
Hello again,
I have made the changes you suggested and the results have not been as expected.
When I decrease the value of 33uF, electric discharges are accelerated and consumption increases. I have tried to increase the capacity to 100uF and the electric shocks decelerate a bit, but the consumption does not decrease much.
With the resistors I have increased its value up to 1K and, contrary to expectations, the electrical impulses have increased a lot.
I do not understand the behavior of the circuit.
I do not know what else to do
Anticipated thanks
Swagatam says
Hello,
referring to this diagram:
https://i.pinimg.com/originals/25/43/86/254386ef48326a818a37d430de75c8dc.jpg
the circuit is a simple transistorized astable multivibrator where the two transistor sides oscillate alternately with a delay time determined by the values of R1/R3, and C1, C2, …or simply all the 4 components combined decide the ON/OFF intervals. Higher values will give higher pulse delays and vice versa.
To avoid confusion it is better either to change C1/C2 or R1/R3.
When the values of these components are equal on both sides then the pulse delay time is equal on both sides meaning we get 50% ON/OFF timing across the two transistor collectors.
But suppose if you increase or decrease either C1 or C2 will result in the pulse delay across the transistor collectors to change and become un-uniform.
In other words one of the transistors will produce narrow pulses while the other transistor will produce wider pulses.
Narrow pulse will allow short switching time of the transformer and therefore low battery consumption and also weaker sparks, while the wider pulses will cause higher consumption and stronger pulses.
So you have to identify with trial and error reducing which capacitor reduces the pulse intensity. Keep testing with reduced values until you identify the right consumption value.
And increasing R2/R4/R5 values will definitely help to reduce the overall consumption because in doing so the switching current through T1, T2, T3 will reduce proportionately.
Since T3 inverts T2 pulses, adjust one of the capacitors such that T2 gives wider pulses, this wll cause cause T3 to conduct more and reduce T4 conduction and help to reduce the battery consumption.
Pedro Cardona Vives says
If someone had a circuit that does the same functions but with a reduced battery consumption, I would appreciate it very much.
Greetings and thanks again
bhanu ss says
Hallo sir, i want to make a flying insect killer from your mini fence charger circuit. so please suggest me which type /model/number ferrite core transformer should i use in that circuit ,instead of iron core transformer?? what are the values of c2,c3, c4 and c5 . does the c4 and c5 are ppc one ? thanks in advance
Swagatam says
Bhanu, the concept presented in the following link will perhaps fulfil your specific need:
https://www.homemade-circuits.com/mosquito-swatter-bat-circuit/
bhanu ss says
thanks a lot for your quick response!
BHANU PRATAP SINGH SOLANKI says
Sir, in above mentioned mini fence charger circuit, what is the value of the TRANSISTER “T1” ?
Swagatam says
You can use 2N2222, 8050 or TIP31, or D1351
nwn says
hi…
if i need to get 8kw from this ciruit, what kind of changes has to be done?
Thanks
nwn says
8 kv
Swagatam says
Hi, you will have to build a custom transformer, and use mosfets for triggering the primary of the trafo. It will be like a 8kW high frequency inverter circuit
jody says
I made a fish shocker using a ign coil which lead do I let grag the lake bottom
Swagatam says
obviously it’s the high tension cable from the ign coil block which you should use for the shock.
Bhargav Patel says
Hello sir,
With the DC Circuit how much area of the farm can be covered? maximum?
Swagatam says
Hello Bharghav, you will have to test it practically, it will be difficult to assume it..
Jan Van Vuuren says
Thank you for your advice.
Regards
Jan
Jan Van Vuuren says
Hi Swagatam,
In my country we have a huge problem with armed car hijackers. I want to know if I can install your unit in a car so that it can be activated when you are high jacked. I want to connect it to the chassis of the car so that when the hijackers touch the car they will be shocked by the high voltage. Hopefully this will deter them and they will seek easier targets.
Do you think this can work? I am especially concerned that high voltage can cause a spark in the fuel tank of the car.
Kind regards
Jan
Swagatam says
Hi Jan,
I am afraid that may not be possible, because the car body is huge and this might make the impact very weak, and even if it was made strong it can't affect the intruder since the intruder would be wearing shoes, and without an earthing the shock would become ineffective, so the concept won't work as assumed by you.
and yes the fuel tank is another crucial thing which might need to be considered…
~ô¿ô~ says
The charger design discussed here is not considered low-impedance output is it? If I understand correctly, a low impedance current would have a final transformer with a low ratio winding.
Lalith Bandara says
Hi, is there any place to buy this as a Electronic Kit? Thanks
Thushara says
Hello Swagatam,
The circuit works,But,
1)The output pulse length is short,if adjust the 1M pot.
2)Not work with 12v Dc Battery.
Pls help me.
Thanks.
Swagatam says
Hello Thushara, the circuit will definitely work with a 12V battery but make sure it's rated at, at least 7 ah
for increasing the pulse length you can try increasing the 1uF capacitor to 10uF and see the difference…and also replace the 22K resistor with a 100K pot so that you get an additional option for optimizing the PWMs
sanjay bharvad says
Hello Swagatamsir
I want to add siren with this circuit for fencing use to protect my farm …. When wild animal touch wire I want to blow the siren ….plz help me
My mail id Sanjaybharvad138@gmail.com
Swagatam says
Hello Sanjay, the siren will need to be configured separately by using some other concept such as through an IR based alarm system or a vibration detector etc…It cannot be done within the above explained circuit…
bursach says
Ok, I will give I try. But beside this car bobbin everything seems to be clear to me .
Thank you!
Swagatam says
sure! wish you all the best
bursach says
Thanks Swagatam, one more question, the high voltage bobbin I have has primary with marks 15 and -. The secondary of Tr2 going to one primary of the bobbin I suppose to + (15). From SCR , end going to minus (-) and earth of fence. End of C4 going to bobbin secondary. The other end of secondary bobbin going to fence(high voltage). My bobbin is from a car, and has short with one end of primary and one end of secondary. Will this work in this way?
Swagatam says
Sorry Bursach, I am not quite able to figure out your trafo specs from those markings.
I think a relatively easier schematic is discussed in the following article which you can try with less difficulty:
https://www.homemade-circuits.com/2013/01/make-this-enhanced-capacitive-discharge.html
you can try the first diagram
yes the SCR left pin will go to the ground
end of C4 is going to the primary pin of the ignition coil
If you are using a car ignition coil, then probably you could take the help of the diagram presented in the following article
https://www.homemade-circuits.com/2015/03/making-strong-rf-discharge-circuit.html
bursach says
I think these are ordinary transformers but compact, check this link, what I mean :
http://www.kelco.rs/katalog/detalji.php?ID=6928
I think these Tr are not ferrite.
Swagatam says
yes, these can be used!
bursach says
Thanks Swagatam, I suppose 2×1.25A= 2.5A for Tr1 with 30VA and 2x12V will be enough ?
Swagatam says
The specs for both the trafos could be approximately 0-12V/1Amp/220V
bursach says
Ok, I will make my own. Can I use for example Myrra transformers to montage to pcb? The second Tr I have is 2×1.25A, is it sufficient or it has to be just 3A?
Swagatam says
The transformers are ordinary step-down iron core type since these are supposed to be used with the 50/60Hz from the mains, ferrite versions will not work
bursach says
Hi Swagatam, is there any PCB for both circuits?
Swagatam says
Hi Bursach, sorry no ready PCB designs for the circuits
Unknown says
sir give ur number pls
Gom Dorji says
Sir, since the output voltage we get is in pulse how can we measure output voltage?
Swagatam says
Gom, 20kV can be difficult to measure with ordinary DMM….but it's not required…you can judge it visually…if the spark is able to fly across a 1cm gap or more then it's well over 20KV
vishwa karanth says
hi swagatam,
Can we use this circuit to energize 4KM ?
Swagatam says
Hi Vishwa, yes it looks possible since the voltage is high enough, around 20kV
Gom Dorji says
Sir, I have read your home made electric fence energizer and found very simple designed and cost effective. So m also planning to design one electric fence energizer with following parameters;
Input 12v DC
Pulse width 100micro secs
Maximum output is 2joules
working length is 200m to 40km.
Therefore can you kindly advice me.
Swagatam says
Gom, pulse width can be set by adjusting the 22k resistor value appropriately.
however I am not sure about the joule calculation,, you can probably do it by yourself.
for 40km length you may have to install many such circuits at appropriate intervals for enabling an effective outcome from the units.
Gom Dorji says
Thank you for your reply. Let me try it .
mukptl says
can we remove TR2 and use direct 230 ac ?
if removed tr2 and trigger SCr from 555 will work ?
please see this
https://drive.google.com/file/d/0BzbroLfbdv4haE53eWxvc0Vmdk0/view?usp=sharing
Swagatam says
In your drawing the SCR will instantly burn, since it's directly connected across the mains…and anyway it looks dangerous.
instead, you can try one of the designs shown in the following article:
https://www.homemade-circuits.com/2013/01/make-this-enhanced-capacitive-discharge.html
Blue boy says
Hi will this work on a colourbond roof? I'm desperate to stop intruders, thank you
Swagatam says
the wiring will need to be done as done for fences, if you just connect it to the roof it won't work
mukptl says
hi Swagatam
i made this fence circuit but its working fine for 1 minutes
after 1 minutes traic BT136 getting hot and spark stops
whats cause for that ?
Swagatam says
Hi mukpti, you can connect a heatsink with the triac or use a 10ohm/5 watt resistor in series with its supply leads
mukptl says
thanks for reply
now am changing from 230 ac to 12 dc power supply options
for that i am going to replace bt136 with tip122 and 1k resistor with 100 Ohms that connects to tip122 Base
but i not sure with 3 legs of tip122
1st leg of tip122 connect with output from timer 555
2nd leg with TR2 and 3rd with ground wire
is that correct ?
Swagatam says
I can specify the leg orientation here, but it would be better if you check it through an image.
just type and search TIP122 datasheet and you'll be able to get the complete info regarding the device, or you can click the "images" option in Google search for getting an instant view of the same
mukptl says
Thanks a lot
i made it working but still tip222 getting hot
Swagatam says
it will get hot, you will need to add a heatsink to it…..also try increasing its base resistance from 1K to may be 22k or even higher.
mukptl says
can tip122 replace with MOSFET irfz44 in 12v dc model or BT136 replace with MOSFET irfz44 in AC230 model to solve hitting problem ?
thanks
Swagatam says
mosfet cannot be replaced with BT136….it can be replaced with TIP122 in the DC model
mukptl says
thank you
Atif Javed says
and what is 1M pot is it a variable resistor which adjust the frequency
Swagatam says
yes it's for adjusting the 555 IC frequency
Atif Javed says
sir can y guide me whats the exact purpose of first circuit which make a alternate voltage and how its operate
Swagatam says
the first circuit is explained here:
https://www.homemade-circuits.com/2011/12/how-to-make-capacitive-discharge.html
vikas loh says
hello sir
any idea about make alarm circuit when fence wire is short.
please give me circuit.
Swagatam says
hello vikas, it could be implemented using a current sensor stage…..if possible I'll try to update it in the above article.
samaj says
Hy Swagatam
i like your ckt but have some questions
there is some difference in the part list and fig -2 also some parts from fig 1 also differ from fig-2
so which is completely write part list or fig-1 or fig2
thanks
Swagatam says
Hi Samaj,
I'll do the necessary corrections soon. thanks
Ramesh Valaki says
dear sir
i want to make solar fence enegiser. i m from chemical field so don't have technical info.so plz guide me for the same. can we have ready made circuit for energiser?
Swagatam says
Dear Ramesh,
I think the following circuit will be perfect for your applications:
https://www.homemade-circuits.com/2012/05/make-this-solar-powered-fence-charger.html
Abu-Hafss says
Hi Swagatam
For my CDI bench test, I want to switch off the traic whenever there is trigger pulse. Please check if following configuration is OK:
https://dl.dropboxusercontent.com/u/20969135/Traic.gif
I haven't used traic before so please suggest me suitable values for the resistors and how much collector current would be enough to operate BT136?
Swagatam says
Hi Abu-Hafss,
It's correct, the resistor can be any value between 2k and 10k as the triac would require just 15mA or even less to trigger fully.
Abu-Hafss says
Hi Swagatam
1) According to the circuit description, the right transfo should be labelled TR2 and the the left one as TR1.
2) What is the purpose of the diode in the lower right corner, next to the capacitor?
3) Is it important to connect one lead of the primary to one lead of the secondary, of the 2nd transformer?
Swagatam says
Hi Abu-Hafs,
2)the diode is for grounding the negative spikes.
3) yes it's very important for providing the ground to the scr with reference to its gate voltage.
surya smart says
how can i measure the ampere from tranformer?
Swagatam says
connect meter prods directly across the secondary output wires, in the AC Amp range
Swagatam says
a simpler solution is to pulse TR2 directly with the IC555 via a transistor or a mosfet and eliminate TR1 entirely from the CDI circuit.
madushanka gamage says
hai……this circuit is very use full to my home…for wild elephants…please correct diagram send to me..my email address is – madushankagamage445@gmail.com –
Swagatam says
it's current that may be lethal, not voltage, it will depend on the transformer current rating.
Rakshak says
dear sir sir how measure 20,000 v
thanks
Swagatam says
The capacitor accepts and stores the 220V input, and in the process when the firing limit of the SCr is crossed, the SCR fires and shorts the capacitor leads across the connected winding of the coil discharging the cap voltage into the coil. This discharge is stepped-up by the coil to the specified levels at the high tension output….so this is how it works.
Swagatam says
the negative terminal is the ground point.
the positive terminal goes to C4.
the central top cap is the high tension terminal.
you may refer to this diagram
static.ddmcdn.com/gif/ignition-system-coil.gif