Відео

Depending on your electricity contract, even negative prices are possible. There are people who get paid to use power during days with lots of sun or wind. But yes of course on average energy prices have generally increased, mainly because of natural gas and oil prices going up.

Even pop stars need a hobby, this channel's mine

Well of course the power grid is kept perfectly stable nonetheless (or it would fail), but introducing extra load during the day makes this easier to do for grid operators. Oh and yes it is an oversimplification, normally I like to make 20+ min videos going into the details and nuances, but unfortunately these shorts are limited to one minute haha.

@@AKIOTV Absolutely, not trying to being negative or criticize you. Your full videos are great. Love the series on SRM and you explain it

It depends on the range required/the size of the objects etc what's best. Normally the lowest frequency they operate at is about 10kHz, which you could technically hear, but it's a very sharp, annoying high pitched whine, so usually, even at lower (audible) frequencies, the tone the operator hears is not the carrier signal itself but indeed something derived from it.

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@@AKIOTV thanks for very quick reply sir.

Name?

@@AKIOTV Yeah, just wondering if you knew about the name or type of the rotor. Because there are thousands of different of type, sizes and spaces between. :) Would love too copy your work and test it out before i would go for anything bigger system.

@@MrLasox The tracker is DIY (made a full video on the build), the motor it uses is a NEMA23 spec stepper motor.

as far as I know, these fish can produce a voltage across different parts of their body. Say their head is positive and their tail negative, the current will run from the head, through the water to the tail. If you are also in that water, some of it goes through you. The closer you get to the fish, the more of that current flows through you. The same would happen if you dropped a sufficiently high voltage battery in a tub and went near it.

You could make it fully analog, but that eliminates a lot of flexibility in the design. Pretty much all grid-tie inverters on the market also use microcontrollers to do the job. The PLL can be implemented in the firmware of the controller. In fact, the method I use could be seen as a basic variant of PLL. I do like the idea though, there's a certain elegance to a fully analog design so I might just try it in the future.

@@AKIOTV It's the elegance you mentioned that gets me. I'm a programmer by trade, so seeing something solved in code almost always leaves a "so what?" Impression in my mind, but a circuit crafted to achieve the same job is mondo cool. One might even describe it as "rad".

This is possible, and in some cases it's done, but I don't intend to use this as a backup power system. I have another non grid-tie inverter (which is significantly more powerful) that can power my stuff during an outage.

Ah yes, I blew up one of these things too. The reason I blew up mine is that the BTS7960 chips that it uses have the low side switch on by default. So if both half bridge devices are enabled, and both PWM signals are low, the low sides are turned on, creating a short circuit through the ground rail. This happens all the time during PWM and is no problem then, but if it happens for a longer time you're done. My mistake was that I programmed the arduino to go into standby mode upon detecting a problem, but then I forgot to add some code to disable the EN signals to the bridge, leaving the bridge with both low sides on with the AC side hooked up. My thing seems to have no problem with the DC power being off, as long as the inverter is in standby mode and the H-bridge switches all disabled. Would it be possible that your microcontroller enabled the bridge (for instance because it was also powered from a laptop or something) without the DC connected? That could create essentially the same condition I had. I put the scope across the shunt resistor on the low voltage side on the transformer to see the current. Forgot to include it in the video, but it looks reasonably smooth, although less smooth than the voltage. I think I'm going to put a picture of it in the folder that has the schematics and stuff. BTW About the battery charging, if it's a simple lead acid battery you might be able to cheat your way into doing this by just using the diodes as a rectifier. You'd just hook up the H bridge to a tap on the transformer that has a slightly higher voltage than the battery and it'll charge passively with the bridge turned off. You could use a simple relay to select the right tap on the transformer, connecting a lower voltage one for sending power onto the grid, and selecting the higher voltage one for automatically charging the battery. It's pretty rough and you'll have no control over charging speed etc. but it'll work, my old school lead acid battery charger is also nothing more than a transformer and a rectifier. (which is in that thing actually a *single diode* haha)

@@AKIOTV I think you're right about the way I blew up my H-bridge. I had the enable pins driven high before the battery was connected and the correct pwm signals where applied. Won't make that mistake again. Yes please do put a picture of the current waveform in the zip. My current waveform looked very rough, I was expirimenting with many different inductor values and even wound my own on different core types, problem is finding one that has enough inductance, and doesn't saturate up to about 15A As for the charging part, I have to say I first though of doing it exactly the same way you described, but this would indeed require a perfectly matched transformer winding/tab + the power factor and efficiency would be horrible as a rectifier only draws current at the peaks of the sine wave. Then I found out how victron inverter/chargers work! It's nicely explained in this video: ua-cam.com/video/UPfUn5ki7OM/v-deo.html Basically it's working like a buck converter in inverter mode, and like a boost converter in charging mode. The pwm duty cycle is always following the grid waveform, but is controlled in such a way that it aims just over the grid voltage in inverter mode, and just under in charging mode, causing the current to flow the other way. In this simple simulation you can see how this works with a simplified half bridge version: www.falstad.com/circuit/circuitjs.html?ctz=CQAgjCAMB0l3BWK0BsB2AnADgEwI5gMw6SFZYSGEhIAs1CApgLRhgBQAZiISliDhy0Q9HAKE9qYaEhgduvfoQRjRPFTzHTZ0DgHcRxAeUNihkKOwDmpkWBS3atfhcjsANrZwn8Zk69hICGlCSBJiQgxIBDgUFAQ0SwM1b341Kgc3G18eLGEcpxcknj5xYUVjF3YAJR5IYVSBND8isRi4Gk6AtBR2ACcQHv5GrBQG-2QOAGMaDDEyfLnKqGR4OAwNza3tjBBmFF0cTebCWjQ4c8zAjgrz8f47spW3MGaQUfuQDDAWlcSHIoBJAANQA9u4AC4AQysjHYADcBJA0vYkcMJK4RBYwJigewDCQUQ41LRUW5kkYKiSyfjJA4fmkjAzimpmSlkcUKo0KsoxG4qUzvLYsLj2ABJOqfLkTYL886zX6PRoQbHsAAeXzOAiWbDi2ro4H4AHE+gBLAAmAB0AM5TUEAO3tjCmEMYVutEL6UPt1s4oL6AFtGH11YMwLtThAohGnCJDSAAOqm+3m5NWAD0elNfUYNpz1tNHu9UzhBiGyyV-lD4f4rDEGAQEGYu2EYH4AAVQXpgzbOO4u9be31QQGbQAjKEQ119ACeNohoJtVjN7r0AAtGPabQAKCdT4Nz63w8HQ2E2gBUNvNAFcITOpvf3IwAJQ2gB8S5XNuPkJhucH1rbgAQteUwANY2gGoLmi+1YEAIwgNg4OCJK2HZdj2vr9noAGcMOo7WsuFrzou1p7tOh7rpuO7kQe34nn+F5Xre96Pi+NoADyfsRR4MWeAHAaCoIejaACy0GwQMhJPNJzIBNMdLgEKGTgCguKwFG0DfGAtD4DiaBoMoGC8KsQTWIp9gWCpryZJYGo4mh2LGYa1CthAYr2tO9pQu4eaMAWRb2iWtKycpJlyaGpLCKwYDUHw0VsBYDTCB58LBtONoAMJrlCfSwn0NoAA5mkFpqFU+7Cggh4ArLQkAbOAFgHMIFhmOU7BkO8IAAGIQLIjUWKwIAACIsVlbHsEAA

@@nielsdaemen That is a much more proper way of doing the charging thing. It would be quite elegant if you could implement that with merely a software change. I've added the image to the folder. It's not a perfect waveform, but I'd say it's all right. I suspect the current waveform is more dependent on accurate synchronization than on the filter itself.

@@AKIOTV That current waveform looks quite alright indeed! Another thing that infuences the current waveform is if the grid waveform isn't actually a nice sine wave. Where I live, the grid waveform always has a huge flat top, so when the inverter tries to output a nice sine wave, it will deliver a bug current spike at the peaks because the difference between the inverter output and the grid is larger.

@@nielsdaemen True

A toroidal transformer may help. Not entirely sure, perhaps I'll give it a go. The most ideal solution for mains voltage/current monitoring would be a similar device to the cheap power meter I use now, except one that has some interface to connect to the arduino.

@@AKIOTV Yes, thought and inquired about this a lot - I want to measure power and direction so I can control both charging and the a grid tie inverter to minimise the power drawn frin or sent to the grid. I've been told I need a quadrature detector.I'll see what I can find on aliexpress. I'll post back when I find something suitable.

You mean the thin ones? Those are from some 5-wire cable I had laying around. They're actually quite nice.

the wire *diameter* I used for the current version is 0.8mm. Thinner wire you can fit more turns on each coil, thicker wire will handle more current. Ultimately the maximum field you can generate is the same either way, but a certain number or turns may be better suited to a particular power supply. If your supply can handle high current but is low voltage, use thick wire/few turns, if the supply voltage is high but you can't supply much current, use many turns of thin wire.