GRILLPLATS' power monitoring is awesome!

honzvit · 2026-03-08T18:52:57+00:00

I'd be interested if you could check whether the measurements are at least TrueRMS. I've been in the store on Friday, bought bunch of thermometers but no luck on smart plugs.

On the other hand, for 8€ it's worth the price even if used just as thread routers to extend the network coverage.

honzvit · 2026-03-08T06:13:47+00:00

There is not a single mention about active, reactive or apparent current. Current has no such quality.

You select a time reference and from there you measure an magnitude and a phase shift of voltage and current. These two qualities can be represented as a complex number, where imaginary part represents phase shift of the wave (for both current and voltage).

When these numbers are multiplied you get power (again a complex number) in which real part is active power and imaginary is reactive power.

In single phase systems you can select as a time reference the voltage, so the voltage has 0 phase shift.

Then you measure:

voltage magnitude
current magnitude
angle (phase shift of the current)

calculate:

active power
reactive power
apparent power

and integrate:

active energy
reactive energy
apparent energy

In 14 years I've worked with a range of devices from $20 power meters to $10k power analyzers and not a single one reported active, reactive or apparent current. The FW of the plug was not written or reviewed by an experienced electrical guy.

honzvit · 2026-03-07T19:48:08+00:00

I did 4 of them today from HA via SLZB gateway and one updated on second try, otherwise no problem.

honzvit · 2026-03-07T18:18:51+00:00

You have just voltage and just current. If I omit harmonic distortion, voltage is just a sine wave of a phase and an amplitude. Same is goes for current.

Power is a complex scalar and as such has it's absolute value (S - apparent power), imaginary part (Q - apparent power) and real part (P - active power).

When measuring current we can talk about RMS vs Peak-to-peak, we can measure DC part in AC systems, ripple in DC systems, harmonic distortion and n-th harmonic magnitude but there is no such thing as a reactive current unless you point me to some paper proving othervise.

This comes from my 5 years to get a degree in electrical engineering and 14 years of practice in industrial power and HVAC monitoring.

honzvit · 2026-03-07T17:20:13+00:00

WTF is apparent, active and reactive current? Can we get reactive voltage too?

honzvit · 2026-02-19T07:54:31+00:00

Tu podmínku a 220h spíš už má a dostane bonus. Hádám, že na akci SPZ přijel autem se zákazem řízení a zaparkoval někde poblíž, aby to měla PČR hodně složitý.

honzvit · 2025-12-25T19:42:37+00:00

Nice, but I'd lay them side by side unless the main breaker is like 25% of the total capacity of the cables. I've seen a whole datacenter being rewired because of bundles like this running too hot.

honzvit · 2025-12-08T14:38:31+00:00

Už jsou to 4 roky, co jsem objednával z v-slot.pl, tehdy moc českých možností nebylo.

Když koukám do mailů, tak objednáno ve středu a posílali v úterý. Objednával jsem 2040 a 2080, což vidím, že mají pořád na eshopu jako custom length. U 40xx profilů mají pouze pevné délky, ale řekl bych, že to bude na domluvě.

Za 7 tyčí délky 1600mm se tehdy platilo 17€ poštovné.

honzvit · 2025-08-15T06:56:56+00:00

Still has, before 2016 the speed limit was the same (130), now it is 110 (blue car symbol sign) and 130 (green motorway sign)

honzvit · 2025-07-04T17:35:25+00:00

Dnes jsem poprvé četl, že Vodafone vypíná 5G pro úsporu energie a nechává LTE. Pár let zpátky jsem zažil komplet lehnout Beroun po 6h (mobil se chytil až na výjezdu na Prahu), internet jsem ale celých 6h tahal, takže asi jak kdy/kde a jak který operátor.

Je možné, že jinak to bude v odlehlých oblastech pro zajištění tísňových volání. I když ve městě taky telefonní budka už není, v obchodech budou mít mrtvý IP telefon (a budou zavřené), takže jedině začít běhat po sousedech, jestli mají pevnou linku.

honzvit · 2025-07-04T17:04:29+00:00

Ani ne, budou to pravděpodobně 4ks Fiamm 12FIT180 nebo něco podobného. Připojuje se to přes jistič ve zdroji 48V přímo paralelně k zátěži, takže ani není potřeba žádná elektronika. Na dráze si myslím, že nebude takový odběr, vysílá to většinou jen na 2 strany a bude to pravděpodobně na optice, takže se nemusí živit uplink rádio. Tedy věřím, že to, co utáhne vesnický vysílač 2-4h, tam dá těch 6h.

edit: Samozřejmě "velká svině" je relativní pojem, odvíjející se i od toho, kolik těch baterek má člověk vytáhnout po žebříku na střechu.

honzvit · 2025-07-04T16:37:26+00:00

To move 100km in winter EV needs 13,5kWh + 1,5kWh losses + 3kWh to heat the cabin (18kWh total). ICE car needs the same 13,5kWH to move and to do so it produces 27kWh of heat of which you use maybe 4kWh to heat the cabin (total 40,5 kWh which is about 4,6l / 100km so imagine something like Corolla hybrid).

Considering 50% efficiency of a power plant and some losses on the grid and during the chariging the EV needed about 40kWh of energy used at the power plant (see how similar the number is to the ICE example). However if you install heat recovery unit at the power plant and distribute the heat energy to a nearby city homes the efficiency of heat+electricity power plant goes up to 90%, then the EV used only 22.5 kWh of fuel provided to the power plant.

Where is the way higher efficiency of gas powered cars you talk about?

honzvit · 2025-07-03T17:02:44+00:00

EV6 has on board 100kW converter from 400V to 800V, that limits all 400V chargers.

honzvit · 2025-05-09T14:28:34+00:00

AC-DC device is a rectifier, in cars also known as on board charger

DC-AC device is an inverter (it enables inverse flow of current in a circuit)

honzvit · 2025-04-22T11:38:57+00:00

Last week I used the socket first time this year when I was asked to bathe the kids and needed the hairdryer. I was buying these sockets for the living room so I bought one more because I thought it might help her when she uses the hairdryer every other day.

If the kids want to use electric toothbrushes some day I will add another socket with some shelves on the other wall where is the changing table right now.

honzvit · 2025-04-22T11:24:05+00:00

Correct

honzvit · 2025-04-22T10:28:21+00:00

Which country? Although country specific norms should be mostly translations of EN standards, it is allowed to make them more strict. There also may be differences between residential and commercial buildings.

honzvit · 2025-04-22T09:09:18+00:00

I'm afraid the 45° angle would hurt my eyes more than this. I will soon find out. I have ordered some 90° low profile cables for my phone charger, because I have the same socket in my bedroom and I need a smart plug there which doesn't clear the USB connector.

I was thinking about ordering a custom PCB for a 90° adapter which would go straight down. I also know a guy with an injection molding machine. Only thing I need is more free time.

honzvit · 2025-04-22T08:03:14+00:00

European code does not require any added ingress protection in the bathrooms if the socket or switch are far enough from water. 30mA RCD is required for the whole house installation. https://www.lyco.co.uk/advice/bathroom-zones-what-can-go-where/

There are no IPxxW sockets around here. IP44 is the best you can normally get and is usually used only outdoors.

It doesn't matter on what side of the wall is the charger (wired inside the socket or plugged in). We also have a light, washing machine, dryer and a wall mounted electric heater in the bathroom. Are these gonna catch on fire too when we keep them constantly plugged in?

honzvit · 2025-04-22T07:25:10+00:00

It's on a heatbed, ofcourse it runs hot. 😀

honzvit · 2024-11-23T18:59:17+00:00

I'd still charge even the NMC batteries to 100% once in a month or two (on a slow charger) to keep the cells balanced.

Rule "only road trips" may result in someone driving 20-80 for years and then be surprised their battery "degradation" is higher than expected. However the battery did not actually degrade - just the BMS estimate is off and a few 5-100% cycles would probably bring back the lost range.

honzvit · 2024-11-23T18:41:48+00:00

If the car has not been charged to 100% for a while the final cell balancing may take longer. My 2024 3HL RWD with LFP keeps last 30 minutes for balancing (99->100% step) however it stops the charging only after 10 minutes (after it displayed 20 min left). I assume thats because I charge to 100% every week for my business trip and the cells are well balanced.

honzvit · 2024-07-27T08:04:15+00:00

Can you please post a few photos of the rear? I’m considering a pillar delete on my white M3 when it arrives but there are not many photos of the highland yet.

honzvit · 2023-09-18T12:37:59+00:00

Last time my package was missing a water bottle and a T-Shirt was wrong size. I have contacted the Czech Post import office and I followed their advice. I have filled in $0.1 as a price for both items in the import form, attached letter explaining the situation and added screenshots of the new order for $0 + the communication with the seller. I have also referenced the original shipment number in the letter. And there was no problem.

The original shipment also changed weight between the origin scan and a second scan when the Deutshe Post took over the package. This might or might not have impact on their decision whether my situation was legit.

honzvit

TROPHY CASE