Huh, that’s weird. Double checking the part markings would’ve been my next suggestion, but the picture shows they’re correct. Maybe try a 1kOhm load resistor across Vout and GND, though in theory you should be able to see the output voltage without it.
The “typical application circuits” on page 2 in the datasheet ww1.microchip.com/…/MCP1700-Data-Sheet-20001826F.… shows both input and output being decoupled with a 1µF cap, have you tried that? I haven’t worked with the MCP1700, but I have had other LDOs fry themselves because the decoupling malfunctioned.
I’m not saying that your LDOs are fried. What I am saying is that some LDOs don’t take too kindly on not having the company of some nice caps.
What just caught my eye is that the datasheet specifies ceramic non-polar caps. That seems a bit weird. Just drawing a non-polar would have made sense, but specifying that it is a ceramic is strange. Using a ceramic makes sense, I mean there are 5 times the ceramic 1uF caps on digikey than there are electrolytics, but it should be technologically agnostic… I’d probably try to get some 1uF ceramics for testing.
Very weird looking tearing, but if you are playing 24, 25, or 50 FPS content on a TV or monitor that is locked to 60HZ it is going to tear, some handle it better than others.
I suspect your output is set to 60hz or something and you are watching content that isn’t at either 30 or 60 and your playback software isnt doing autoswitching (kodi, plex etc do this, but not web browsers or apps like netflix)
So it’s not a hardware fault, its just the reality of watching media on a computer with an external display, so it’s a software configuration problem.
Also, considering the severity of it, are your video drivers up to date? that amount of tearing is close to what you’d see when running standard vesa drivers like when you have no video driver installed at all.
Edit: I want to add that this problem occurred from one day to the next. I’m using Jellyfin as playback, but this effect even occurs when moving windows over the screen
Solved: Ok, it seems to have been a software problem. That had to do with the sync. I have installed ubuntu on the laptop for now and everything works again. Some update seems to have shot something. I am now using a
Here’s something I’ve been using in my own esp8266 projects for a while, LiFePo4 18650 cells. Their working voltage range, 2.6 - 3.6, 3.2v typical, makes them perfect for esp chips, and you remove the quiescent drain (though really low for mcp1700). Downsides of LFP being, lower capacity in the same size (energy density), pouch cells are generally not available and LiIon is a far more mature tech, with easy (and cheap tp/tc 4056) charging solutions.
don’t really accomplish anything. The first line is bit shifting to the right 8, and then you just bitwise and it resulting in the same thing. For example, starting with input_bin:
So, every time you go through a cycle of the for loop, you’ll just start with the same values in upper_byte, and lower_byte. To sequentially output each shifted value, you’ll instead want something like:
Note: Lemmy has a bug where it doesn’t format some symbols correctly, so the left angle bracket gets formatted as <. The same issue exists for the right angle bracket, the ampersand, and I would presume others.
Hmmmm do you want to write to both shift register at the same time? I say this because you’re looping 16 times, but seem to be sending the high and low bytes out 16 times over rather than one bit each time, although you are shifting the input.
You want to put the batteries in parallel, so you’ll have double the capacity. Installing them in a series would increase voltage and most likely damage something (mixing 12V systems with 24V battery pack doesn’t really work). Increasing capacity with another battery can cause strain on charger components, so make sure they’re beefy enough or at least have proper protection against overcurrent.
People are correct that you should use the same capacity batteries, preferably the same make/model and age. Mixing batteries can cause problems where one battery drains faster and other(s) start to charge the lower level one so you’ll have less useful amp-hours and that degrades batteries faster.
Switching batteries with a relay or a switch is possible, but you need quite big and good quality relays/contactors for that as current can be pretty high which can cause arcing and even weld contacts together eventually. With proper parts it’s a safe way of doing it, but personally I’d just get two batteries in parallel since there’s fewer components to malfunction and adding complexity with arduino+contactor doesn’t save that much money, specially if you place any value for your time (which of course isn’t necessary, tinkering itself is often worth the time spent).
The issue is that I cant place two of the same batteries. The extra one has to go under the passenger chair so it will be a completely different battery. I’m not completely sure that we won’t be running into issues then when linked in parallel.
I agree that the relay option it’s added complexity and finding the right relay is a bit of a challenge haha. Also there probably will be a short drop in voltage or I have to switch them shortly after each other. So both relays are closed at the same time for a little bit. I don’t know if that would fix the arcing? It will be linked in parallel for a little bit then I guess.
Get a switching relay or one normally closed and another normally open one. That way there’s no paraller connection at all. Connecting two batteries together with different voltage levels causes a huge current spike, think jump starting a car and how thick those cables are. Arcing will happen on the relay contacts no matter how you switch it if there’s load connected.
And since you’re not talking about a trailer, is one of the batteries for the car itself? Since if you’re planning to use the secondary battery as a car battery too you need very heavy wiring to give starter enough amps to run plus running that over a relay is a whole another beast to manage since starter motor can pull hundreds of amps momentarily.
Is an extra utility battery. So that shouldn’t give any issues for starting. That’s a separate battery. I’ll try to find one of those relays. I know I can search myself but if you have any suggestions they are always welcome:)
So you’ll have total of 3 batteries at the car? One for engine, existing utility battery and now you’re planning to install another utility battery, right? That should work. I don’t know how much current you’re pulling from the battery, so it’s difficult to recommend anything. Common bosh switching relay is something you can find from pretty much every car part store for ~5€, but I think they’re rated only up to 40A and I wouldn’t push them to the limit. Check your inverter datasheet how much current it can draw and preferably get a relay which can do double the maximum rating for longevity and stability.
That is correct. 1 battery for the engine and 2 for utility. I guess it has to be quite a beefy one. The interter is rated for max 166 amps. So that’s quite a bit. Which also makes it a bit hard to find a suitable relay.
12V 200A relays are pretty easy to find (I wouldn’t get one from alibaba tho), but that much current requires quite beefy wiring as well. Personally I’d review options to place auxiliary batteries in parallel since that would simplify wiring and the whole system a bit, but as I don’t know how your camper is built it can be tricky or you need to sacrifice storage space somewhere.
And as you’re placing a battery at the same space where people stay be careful with hydrogen. Charging lead acid battery produces hydrogen and in the worst case scenario, specially if you have a gas stove be dangerous if not lethal.
The device is supposedly a 6½ digit DMM yet I currently don’t even trust the first few digits when comparing it to a 3½ digit handheld Brymen DMM. Being reasonably sure that it’s at least more accurate than the Brymen would be nice, so 3½ digits.
I’ve got another desktop DMM, a 5½ digit GW Instek GDM-8255A, on the way, so I could conceivably just use that one as my local “standard” to calibrate against.
The problem however is that the Philips requires a large amount of references to calibrate against (just calibrating DC voltage requires 0V, 3V, 30V and 300V references). Building all references to recalibrate the whole thing would be rather involved, so I was trying to find an easier way.
Easy, you import this puppy www.ebay.com/itm/305042665748 and set up your own business offering calibration services to recoup the cost. Then you can apply for the calibration engineer position at Minerva.
Jokes aside, have you contacted a calibration lab? I don’t know what it’s going to cost, but I can’t think of another way, if you’re not going to built the sources yourself. There’s one in the Netherlands www.minerva-calibration.com/calibration-service/
It would seem from a quick google that I’m not alone in my conclusion. But at least I have found an article explaining the build of the sources you need wolfalex.bplaced.net/…/calibrator.htm
Their pricing for calibrating a device starts at around €400, which is rather more than I paid for this thing and way more expensive than building my own calibrator. So I guess I’ll have to do that…
(…) I have found an article explaining the build of the sources you need
Thank you! Not having to invent everything from scratch is going to make this a lot easier.
400? I guess that’s in the ballpark I expected it to be.
I haven’t studied the BOM for the DIY solution, but something tells me that you’ll only be able to keep the cost lower than 400, if you value your time at close to zero.
With all that negativity out of the way, I’d definitely want to build it myself too. Although my anxiety level is exponentially correlated to the working DC voltage and at 300VDC I’m definitely well in the thick rubbergloves territory. Be careful with the build!
my anxiety level is exponentially correlated to the working DC voltage and at 300VDC I’m definitely well in the thick rubbergloves territory.
Having been walloped by 230VAC, which is far more dangerous, I’m not too worried.
Looking at the schematic you linked above, the amperage is going to be low, which is reassuring. As a safety measure, I’m looking into running the thing off of a battery, so that if the worst comes to pass it simply won’t have the power to be dangerous (1A at 12V translates to a mere 40mA at 300V).
I’d be far more worried about using lead solder TBH (love my Sn100Ni+).
Having been walloped by 230VAC, which is far more dangerous, I’m not too worried.
Well hello there Mr Edison, I didn’t realize the calendar read the 1880s again, please refrain from elephant ownership 😀 First off if you’ve got 300V I don’t care what form it’s in, I ain’t sticking my fingers anywhere near it! Secondly at least AC alternates, giving your muscles a break and possibly a chance to let go of the wire, DC isn’t that forgiving. The reason 230V AC is so dangerous is because it’s usually referenced to ground, meaning that if you touch a single wire, you’ll be drawing a current from that point and to your feet.
But that is all theoretical, because while 300V is stored, and the current may become quite high, it’s only backed by 100nF. Still, I’d want it discharged before poking about though.
The battery is a good precaution. Some of my co-students in university made an EKG apparatus. Our lecturer demanded that anything connected to the electrodes was to be powered by a single battery.
I’d be far more worried about using lead solder TBH (love my Sn100Ni+).
I may be a boomer in this regard, and I’m sorry for the rant I’m about to go on (that last part of the sentence was tagged on after writing the following). I prefer my Sn60Pb40 of which I got several kg from when it was outlawed, maybe throw in a little Ag in there for the 0.3mm SMD solder. TBH my love of lead solder may stem from the fact that I have more, in various diameters, than I’ll ever use.
The first couple of lead free solder brands I got just didn’t flow right. It didn’t help that the solder stations it was to be used with at work, by students, was old school Weller stations that just delivers a constant 24V AC to the iron, and the tips set the temp. All the tips we had were at a temp comfortable for lead solder.
Secondly at least AC alternates, giving your muscles a break and possibly a chance to let go of the wire, DC isn’t that forgiving.
Interesting. Your comment made me read up on all of this. Note that, since Vrms = 1 ÷ √2 × Vpeak, 230VAC has a Vpeak of 325V, so in that respect, it should be pretty much equivalent to 300VDC. I figured that the ability for AC to induce heart fibrillations was the most dangerous factor in all of this, but I hadn’t figured in that DC induces tetanus and can also temporarily stop the heart.
It’s not the volts that kill you though, it’s the amps (the volts just make it easier). I found a table listing the effects of various amperages. It does present DC as generally more safe when compared against 60Hz AC, but I’m not sure how that generalises to the 50Hz AC we have here. I do conclude however that I should be limiting the output current to something something generally safe, like 20mA (which should be fine for a voltage reference). I’m thinking a PTC at the input and being conservative wrt capacitor sizing should do it.
Some of my co-students in university made an EKG apparatus. Our lecturer demanded that anything connected to the electrodes was to be powered by a single battery.
TBH, when it comes to an EKG apparatus I’d also be worried about common mode across the chest, or the power supply having a disastrous failure mode.
I prefer my Sn60Pb40 (…) The first couple of lead free solder brands I got just didn’t flow right.
Yeah, those were horrid. Even the supposedly excellent SAC305 gave me dull joints (tough it flowed adequately). Still, I can only recommend Sn100Ni+ (supposedly closely related to SN100C): flows well and gives me the shiny joints I crave. Having a good soldering iron (I’m using a Pinecil) helps with solderability.
I do however still have some rosin core Sn60Pb40 for reworking vintage electronics. And I do agree that it’s just better when it comes to wetting ability. The peace of mind when working with lead-free solder really is worth it though, especially with pets or small children.
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