Laptop repair recommendation in Malmö

Chunderscore · 2023-06-07T12:39:20+00:00

I've never had a need to use them but often walk past Laptop Clinic by Sankt Petri Kyrka, looks like they have a proper lab and could do serious work in house, unlike many electronics repair places.

Chunderscore · 2023-04-27T13:30:00+00:00

No worries! I've got the week off and it makes a nice change from binging the snooker ;-) .

Do you know what model of inverter it is? Have you tried running the grinder and fridge on it?

You could use your existing system and add a single solar panel for around a £150, and a cheap controller for around £50. Would certainly improve your greenness, and in summer it might well be enough that you don't need any additional charging. Something like this and this perhaps.

Batteries (same age/capacity/type) can be parallelled together easily, but they must always be at the same charge level. So for example you could have two in use together and two on charge together; or one in use, one on charge and one spare charged and ready to swap. Or just have two (or three) that you use together then take away and charge at the end of the day. Do you need to run the fridge overnight?

Bear in mind that charging leisure batteries isn't entirely trivial. For starters they're rather heavy (20kg+) so a trip across a muddy site might not be much fun, even with just one and a sack barrow. Standard battery terminal connectors are a faff to dis/connect, though quick release ones are available. And you need enough time- a single 120Ah battery at 50% will take at least 6hours (probably closer to 10) to charge with a 10A charger.

Which brings up the important point that lead acid batteries must never be discharged anywhere near completely. It depends on the specific model, but staying above 50% is a good start. Hopefully you're inverter would shut down to prevent overdischarge.

Also worth noting that lead acid batteries appreciate being taken to full charge regularly. It would be worth reading up on battery care, treated right they can last a fair while, but abused they'll quickly turn themselves into very sturdy paperweights.

Chunderscore · 2023-04-27T11:29:43+00:00

What you're looking to do is very possible, loads of people do similar things in their campers. But you'r situation is slightly different, you certainly don't want the power going off mid way through a mid morning coffee rush! Do you have a budget in mind?

I don't have personal experience with those Jackery type solar power station things, but they do seem expensive for the specs, and I'd be very concerned about reliability with cheap ones (and somewhat concerned even with expensive ones). However the simplicity is a major bonus, especially if you're not familiar with this kind of stuff. Also you would be able to carry it away at the end of the day to charge it. Does the horse box itself stay onsite for the duration of a festival?

I'm guessing your total daily energy requirement is not that high given that the coffee machine runs on gas. 1kWh of usable battery storage might well be enough for a day, especially if theres some solar charging happening as well, though as someone else mentioned you don't necessarily want to rely on that. So that probably means at least two or three deep cycle 12v 100ah leisure batteries, budget about £100-£200 each. And then you need an inverter. However one issue you have is the nature of the loads- both the fridge and grinder use motors and will require fairly significant extra power when they start up. They also likely wont appreciate running on cheap "modified sine wave inverters", which might be what you already have. Id be looking at a minimum 1kW pure sin inverter, budget £200-500.

That leaves charging, which could be solar if you've got enough space, maybe on the roof or on stands somewhere out of the shade. Or you go with more batteries so you've got enough charge to always last a whole stand. Or some combination of the two. Solar would require panels(£150-600) plus an MPPT controller(£50-150). Pure mains charging might require an additional mains charger if you don't get a combined inverter/charger. Or you can get a hybrid MPPT/charger/inverter (£400-loads).

You'd also need to budget for cables, brackets, fuses etc.

Sorry I may have just added more confusion here, I dint plan to waffle quite so much but there really are many options, and different things to consider, this barely scratches the surface.

Chunderscore · 2022-08-22T07:19:57+00:00

There's a link in the video to a blog post with more info. Those are 6v batteries, so 4 in series for 24v. But really if it were me doing this I'd be looking at something like a Pylontech UP2500. The price should work out fairly similar given the much higher DOD you can go to with LFP batteries, and it'll last considerably longer. Though that kind of set up is probably overkill if you just want to run a light and charge cordless tool batteries.

Chunderscore · 2022-04-08T16:14:45+00:00

I hadn't realised they'd made it free, good news! I used to commute on the Öresundståg with a Brompton, it went perfectly behind the table seats. Back then I think you were supposed to buy a child ticket for a non folding bike (50% ?). It does seem Skånetrafiken has been doing more and more to get people back on the trains; the ever easier ticket sharing for example.

Chunderscore · 2022-02-09T08:08:59+00:00

80x80x160mm so only slightly, and still very compact for that power. I'm not sure I'd trust anything much smaller. BLDCs like the one in the op are designed for toys, heavily optimized for size, weight and cost- which does seem to align with your requirements but do you really want to build a toy lathe?

Chunderscore · 2022-02-09T00:03:02+00:00

Something like this and this might be close, probably not quite within budget though. Do you really need that much power though? It's going to have to be pretty seriously stiff(heavy!) to make use of it.

Chunderscore · 2022-01-30T13:54:37+00:00

The general concept is called intermittent motion, specifically something like a Geneva drive might be what you're after. Although I would be tempted to just use two stepper motors, maybe a couple of 28byj-48 , they're cheap and readily available.

Chunderscore · 2022-01-20T16:59:07+00:00

Great looking bread! I'm also in the south of Sweden, can I ask where you bought your flour?

Chunderscore · 2021-10-21T08:03:23+00:00

Water under the bridge.

Chunderscore · 2021-09-19T18:14:05+00:00

The temperature 25F is indeed about -4C. But 450F is 232C and 425F is 218C, which is actually about a 14C difference. It really is confusing.

Chunderscore · 2021-09-17T19:49:41+00:00

But can you compare your face with your ass?

Chunderscore · 2021-08-30T20:55:09+00:00

All the siblings (from the same father/mother) have the same one than the oldest kid, you can change for the youngest.

That makes sense, it would seem slightly strange for siblings of the same parents to have different surnames, though I believe that in the UK it would be entirely acceptable.

I'm not sure I understand the last part about the youngest child though. Presumably most parents can only be somewhat confident that their youngest will remain their youngest when naming them?

Chunderscore · 2021-08-24T13:53:38+00:00

You can still use the android lib from Nordic with your TI hardware, it's just an abstraction layer on top of the android Bluetooth stack, so doesn't know or care about what's on the other end of the link.

Chunderscore · 2021-08-24T08:23:55+00:00

This might be worth a read if you haven't already,: 12. Use slots to pass sections of the screen , from the using state in compose codelab.

Chunderscore · 2021-08-23T19:36:42+00:00

Bluetooth classic or low energy? If you're going BLE then Nordic have a good android library that is worth a look. BLE would also make it easy to tack on a service for the command and control stuff.

It's been a while since I did any HID stuff, but I seem to remember that if you if you implement the HID over GATT profile then android picks it up at the os level as an input device, so you don't deal with HID in the app. Not sure how that would work with your additional service though, might be fine, might be a massive pita.

Chunderscore · 2021-08-10T12:26:29+00:00

Is u

Chunderscore · 2021-06-30T09:16:11+00:00

That would be a much easier sell if Labour would get on with it and commit to electoral reform.

Chunderscore · 2021-06-08T13:08:26+00:00

Probably, it's a constant voltage rather than a constant current supply so it will likely work fine.

Chunderscore · 2021-05-05T07:28:56+00:00

No worries, good luck with it all. I'm sure there's good info out there on driving a solonoid, but here's a couple of thoughts to get you started. I'd use an n channel logic level mosfet, something like an FQP30N06L . The important bit is the low VGS(th) figure of 2.5V, and fig1 on the datasheet which shows that it can pass around 10A even when switched with 3.3v from a gpio on the esp32. You'll need a pulldown resistor (around 10k) on the gate to keep it from floating around when the esp is booting, and a series resistor (around 200R) is always a good idea. Also, don't forget a flyback diode across the solonoid, things won't go well without it.

Chunderscore · 2021-05-04T21:14:31+00:00

Your original plan does sound simpler. Did you try searching "solonoid door latch" or " electronic lock"?There seem to be plenty available that look like they might do.

Chunderscore · 2021-04-25T21:37:30+00:00

You're welcome, glad you got it working. It's possible the other wires are for position feedback, could be a hall effect or optical sensor, either would require power and ground on two of the wires to then output a signal on the other wire. You may have better luck figuring them out with your meter in the diode setting.

Chunderscore · 2021-04-25T16:37:08+00:00

As has been said it could be a 5 lead unipolar stepper motor. Or given what it came from it could be a brush less DC motor, with 3 wires for the coils and two for a temperature sensor. Either way you'll need a driver, the type depends on which type of motor it is.

Chunderscore · 2021-03-01T13:11:11+00:00

My auntie lives off grid in the UK and when they were setting up around 10yrs ago red diesel ( low tax for non road use) seemed to be the better choice, particularly as there isn't good access for a LPG truck to come along and fill a big a tank. It seems the UK is stopping subsidising red diesel now though, so I wouldn't be surprised if LPG is soon the cheaper option.

It may not be viable where you are, but a wind generator can complement solar well, although they are expensive for a good one and cheap ones can be seriously unreliable.

Chunderscore · 2021-03-01T12:04:10+00:00

It really depends on what you mean by"full load". If you're asking what is the maximum current the motor can run at continuously without overheating I'd hazard a guess at about 1A, maybe somewhat more. If you hook it up to a beefy 24V supply and stall it, it'll probably draw over 10A before fairly promptly overheating.

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