That triangular pulse is 100μs wide and 350V high. Max current is 350V/50Ω=7A. So the max voltage at the terminals is 7A×1050Ω=7350V. So Pmax=7A×7350V=51450W. So the total energy of the pulse is 51450×100μs/2=2.5J. So what happened to the rest of that 8J?
EDIT: I'm wrong here @@babbadge The update is wrong: how does it suddenly become 1/3 ? E = P*t P= (U^2) /R --> E= (U^2) /R *t = (U^2) *t /R And then beacuase of the triangle multiply by 0,5: E= 0,5* (U^2)*t /R 0,5*(7350^2)*100*(10^-6)/1050=2,5725J
P is the same. No matter how you calculate it: 1st: calculation P = U*I --> P= 7350V*7A=51450W 2nd calculation P = (U^2)/R --> (7350^2)/1050Ohm = 51450W
Perhaps the energy stored in the Caps ist equal to 8J, and they just used this as the marketing value. There is probably some of the energy being wasted(converted to other forms of energy)
The MB8 can deliver 8J to the fence when required. The Energiser backs off its power based on what it sees the fence needing. If the fence can power up to 8kV then no need to push more power into the fence. Placing a 500R or 200R load across the output terminals will push the stored energy (as displayed on the LCD) up and the output energy will get to 8J
I just had a look at the website. Australian own business, with available spare parts and manuals. And prices are similar to other big brands for which you can't find spares. I think I know where to buy the next one. I once looked for a replacement transformer for another brand, it was half the size of the one in the video and no center tap and it was going to cost $250.
I wish we could say the same of far more manufacturers today. It ticks me off every time an otherwise perfectly good device has to be disposed of all because of a single unobtainium custom part! We have senselessly become a throw-away society for reasons of pure near-term economics with no thought given to the considerable future costs such incurs...but because we do not pay that cost upfront today nobody seems to care. How many people truly need a new smartphone with each new year? I use mine for 3-4 years before upgrading and they can still run virtually any app I ask of them over that lifetime, it’s only once they have accumulated enough damage or faults (including failing battery) that I finally upgrade, but still we should be properly recycling them (and recovering tantalum, indium, gold, lithium, cobalt, etc.) - instead most ultimately end up in landfills.
Here in Australia, you can be a very long way from help, and you don’t want to throw an entire controller over your shoulder if you don’t have to. Having spare parts available is a must.
legit, this is the only channel with so much, SO MUCH QUALITY content.... you rarely ever stumble upon a channel like that, man i really love your dedication, please keep it up!
Dairy farmer from NZ here, have a PEL 63r fence unit that puts out around 7kv to 9kv. With dry gumboots I can touch and hold fence wires with little discomfort sure your arm twitchs with the pulse but it doesnt actually hurt. Plus a good trick is to stand on one foot when handling wires so your earthing is less but yeah if you touch fence wire with wet boots or manage to touch a nonlive wire at same time then FUCK yes it hurts
@@benduhova1643 I never understood why you get shocked even if you are wearing the black rubber boots there is a layer of rubber between you and ground I understand if the boot has a hole you will get shocked must be the moisture in your feet penetrating the rubber linemen use rubber gloves to work on live lines and they use much higher voltage 13KV + and there gloves are thinner than a boot
@@benduhova1643 We used to use a blade of grass as a resistor to test if the fence was on - get the tingles but greatly attenuated. And in fairness on a smaller unit, but yep still hurt like fuck if you didn't use the blade of grass.
Used to test 10J units by touch, for me no issues, but our lab tech did not believe me and touched. He had elbow and shoulder pains for over a month! Do not advise touching, even though I did hundreds of times myself
And that "12V - 24V" on the input will actually be more like 10V-30V because he has to assume someone is going to be charging a 24V battery system using a truck alternator/jumper cables.
Actually... if you hold onto the fence wire for at least 60 seconds it will kill the COVID-19 virus. Give it try. Trust me... I saw it on the internet.
@@ElmerFuddGun Please add *Irony* for the idiots. We almost have a complete lockdown over here in Germany - not funny. Humor helps though...even for Germans.
@@ElmerFuddGun No, a better way is to take a bath in alcohol. Jokes aside, you can't find any alcohol to buy. But I guess if Russia were to have cases (they do) they'd drown in vodka because the virus is too 'weak' to tolerate it.
very interesting video - esp. the 'demo' of what happens inside of the el-cheapo multimeter. BUT - listening to that 1h podcast - AFTER having seen the teardown - WOW! :-) It's really fascinating to hear those details - about a completely 'foreign' (to me) area of technology....and Paul Thompson ... a very nice guy.
14:00 more light required?? The one thing we care about (the arc) comes with its own light source, and it's already saturating the sensor. No need for more light to light the background, just dial down the sensitivity and live with the fact that the background is a bit dark.
I suspect that without the additional light all we'd have seen is a point of light with little range or definition. Adding the extra lighting I think helps to bring out the detail of the plasma and shows the environment the spark occurred in.
@@virtual812 what I think we could have seen with the right settings is a gradient within the arc, ie that we would be spending our dynamic range on the arc, so that both the lowest and highest light intensity fits within the dynamic range. At that point we might start to actually see some of the structure of the arc.
@@Gameboygenius Sounds interesting, but I don't think removing light is the right way to go about it. Even more light would be be needed again. If there was no light the gain of the sensor would be very high if on auto, and the spark would blow out the image (assuming the gain cannot compensate fast enough) . Alternately with additional light the gain can be lowered thus shifting the usable range up. If gain was manually set it might be hard to catch it at all, or catch gradients.
You're whipping out some cool jargon but you've clearly never shot in high speed before. The point is that the arc IS very bright, unlike the surroundings. So, to see the arc without saturating the sensor, you turn down the exposure/aperture. Then your background becomes black and noisy, so you can't see the wires/desk/whatever (plus it just looks crap).
Dave, if you want a nice long arc from those terminals, place your wires just above a freshly sliced potato. We have had an arc track around 5cm across the surface, but no high speed camera to capture it. Please be aware it will be very loud.
Could be sparking across the range switch. That would damage the meter only in the long run. If you want a very good test of the meter and of a lot other brands, check out Joe Smith RU-vid channel.
Many, many years ago a farming friend of mine needed an electric fence in a hurry. I made him one with a car ignition coil, a relay plus cap, and a 555 to drive it. It took under an hour to make and it worked just fine.
I have, more than once, run into these damn fences. You could be dead-ass tired...ZAP! And then you're wide awake. I still recommend coffee. Cheers, Dave! Keep the family on lockdown so we can circumvent this virus. :)
9:04 “you can have bigger caps in there for the larger Joules versions”. You can’t go much larger in this configuration. You could fit slightly longer ones but otherwise you’d have to stack them and use a larger casing.
i got lots of shocks from those as a kid, the AC ones were bad enough, they sent shocks every other second, so you could let go easy enough, we also had a DC one so the shock was steady, no fraction of a second break in the current, just a steady stream! that one hurt!!
i have that exact same meter that i bought as a quick use one time mine is the "DT830B", still workign after a couple of years with the battery it came with
14:21 I could be wrong but I think that light green color in the spark is the copper vaporizing. If you used wire made of different metals you'd get different colors.
Indeed. You can also dip the wires in a solution of the salt of that metal and let them dry, for example normal table salt will give a nice orange-yellow color from the sodium
It's more about monitoring. As someone who operates a bunch of fence units, regularly checking everything is working properly is a chore that could be sped up immensely if I was getting regular status updates from the fence units. My fences are only a mile or so long. I can only imagine what it's like for the huge aussie farms with hundreds of km of fencing to monitor. NB. Wifi would be a waste of time for me as I'd want to be able to get the updates when I'm not on site or am out of range. The GSM option they offer would be nice, or preferably a Lora-based approach as I already have Lora sensors on water tanks and for weather monitoring.
Yes, I used to work on a farm, and the farmer was always worried about a branch or ornery cow breaking the fence and having the cows get out. That usually results in thousands of dollars of fines, as long as they don't get hit by a car, then it goes up from there. I'll bet that old timer would have loved to have something that would tell him that his lines are intact.
@@DEADB33F The WiFi system is not for local access (when you are within range). It is designed to connect to an Access Point and then to the Servers via the Internet. You can download an Android App, or iOS App on your phone that also connects to the Servers and you now have off-site information. Yes this requires a nearby AP, or a Wifi Extender, or directional Wifi system or a 4G Wingle (Wifi to Cellular) to get the Energiser connected to the Internet.
@@MrShaunwesty Ah, that makes a lot more sense. Still seems like an application probably better suited to a LPWA style last-mile network (LoraWAN, Sigfox, etc) where a single low power GW can cover hundreds of sq km and service potentially thousands of end-nodes. In Europe's case much of the continent already has pretty good coverage by these networks, so for many having their own gateway wouldn't even be required. ....I'd imagine it's the case that because these are reasonably new technologies they may not have been an option when the wifi fence units were originally developed. They're certainly a much better option to Wifi or GSM based approaches nowadays (although those can still be used for the actual backhaul).
The cheap multimeter is great for school! Years ago i bought 16 of Them. But children blow fuses, changing ohms to volts etc. But the thing is sensitive enough for showing foto electric effect (tube) . Minimum current is 0,1 micro amp!
Good on them to sell first party repair parts and give repair resources. Working in an electronics repair industry (or rather used to, thanks covid panic...) we need more companies with this repair instead of replace attitude
When I was about 15 years old my grandparents were moving off the farm and wanted to keep the copper wire from their electric fence. It had been unplugged and pulled off the posts for about a week. They wanted me to just gather it up. It took me about an hour to work up the courage to just touch it. It went well til I was about 3/4 in when I got a good shock from seemingly out of nowhere.
At agricultural shows here in UK they put the leads of electric fence units into a bucket of water , the ground lead is in the water and the line is 25 to 50 mm out of the water on the side of the bucket you can hear the pulse half a mile away. As someone who has had a jolt from electric fences and their energisers on many occasions I can positively state that it is not unpleasant it is BLOODY unpleasant.
You could show how much energy by blasting a hole through thin cardboard, ie backing sheet of a writting pad. I used to show this on the proto units I did for my manager, who used these on his farm. Makes an instant hole!
I see they have a GSM model as well as the Wifi ones. They should consider a LoRa option as well for those who have other Lora-based agri sensors (and those who don't have good mobile coverage). I've been looking at making a few Lora fence monitors for my own use, but the ideal would be having it built into the fence unit itself. Might have to have a crack at making some of those HV opto-isolators. I'd been playing with using a large voltage divider but full isolation would obviously be much better (and make the device more compliant with regs and less likely to blow up).
those connectors are so you can swap out batteries A lot of farmers run these around the clock on batteries and wil drive around and swap them out as needed. I use those connetors for cars I don't use all the to hookup the mower to a charger this winter might. trying to re-condition the battery now.
It isn't surprising that an old, broken electric fence controller was thrown away. What is surprising is it was thrown away in an office park in a city.
I would have thought the capacitor rubber mounting was to prevent mechanical damage over time from the repeated high currents pulses causing the caps to physically 'jump' a little from their magnetic field interactions with the earths magnetic fields.
Why haven't I heard of this company before. I've been looking for an Aussie made fence energiser for nearly 20 years. They're all so dodgey. This looks great. I'll be looking the company up.
Very interested to know if the JVA WEE ESP8266 module has any certifications as is (I think no?) and if the whole system has it as well? Th module looks same as the Itead Wee module.
Does the device continuously send 8J pulses down the fence and into ground (unless an animal touches it)? Isn't that kinda wasteful? Wouldn't it be more efficient to make it detect once an animal touches the fence and then release the energy?
Try getting zapped when they build up a shitload of static charge and the output is 700K. It's like whip going off. Of note, it's good to see that there are companies still operating here in Australia that haven't been brought out by shitty multinationals &/or shipped production overseas killing off jobs and the local micro-economies etc.
As someone who has worked in agriculture for half of my adult life I can say with the pain of experience that yes, they bloody well bite, but yeah, not the end of the world. Worth setting up on a short line of wire and giving it a crack (pun intended) to experience the true joy of the unit. Highly recommended for childrens parties.
Children's parties? I was going to use my $2 Chinese 500,000V module but if you say this works better I will have to give it a try. Thanks for sharing your expertise.
@@MrShaunwesty Ah, always wondered what model and the J's, thanks. It still bloody hurts. I've seen people get tangled in the wires and just get continually zapped, they look like they are having convulsive fits. It's kinda funny :->
@@EEVblog On a Tough Mudder I started running through the wires and the next thing I knew I was inches from the ground doing a faceplant into the mud. There was no memory of getting shocked or most of the fall. I have an awesome picture of me getting up covered in mud. Because I don't learn I keep doing these events - never had the memory loss again but I do run a little lower through the wires so there is less distance to fall.
If you can get access to electronics trash from a business or say a hospital, you can find some interesting stuff. Aaaaaand some stuff you wouldn't want to touch with a million mile long cattle prod.
Yes they do, but that just determines if the code is running correctly. It does not confirm the speed the code is running. When the safety of an Energiser is determined by the speed of the pulse (greater than one second between pulses), the internal wdog is not enough. Two chips with separate timing systems helps to solve this problem.
I remember this video and I've been furnished with a broken energizer, I'd love to calculate it's output power into a fixed load. Whats the formula?. I believe the pulse shape I'm looking at is a exponentially decaying pulse. Vishay have a calculator but not the formular. Anyone help or Dave maybe do a video?
I thought about your comment, the thought train I can see is that a plasma ark would act as a single resistor circuit; I can see how that would drop the supply voltage slightly, but not how it would cause a trough in the voltage from a transformer being shorted. Mind helping me see what you are thinking of?
@@BloodAsp My thought was an arc would be extremely low "resistance", making any current flow through it instead of the resistor divider. No current in the divider -> no measured voltage. But there was no arc so I don't know what's going on.
I touched an electric fence on my great aunt's farm when I was maybe 5 years old. It hurt like hell and you better believe I didn't do it again... until I became a dumb teenager. I discovered an electric fence while I was golfing with my friends on an adjacent property, and of course being teenagers, we dared eachother to touch it until I was dumb enough to put my golf club on it. Felt nothing, probably cuz I was gripping the rubber. But when I finally gripped it with the metal, I got a good sized jolt from it.
