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My Ibanez WD7 wah half-died (see: i damaged it). The "special" IC that created the effect (NJM2777) got damaged due to overvoltage. After trying a couple of circuits, this one is the one that won! V2164 (Quad-VCA) used with single supply, and TL072 for virtual ground and control voltage inversion. PCB milled at work's CNC (yes, i'm privileged😁) Quick 3d print to hold it in the casing (using existing screw ofc) and back in action! So happy i could rescue my 15year old beloved beast with ~€7 in parts (and saved ~150 for a new wah!) submitted by /u/the_lou_kou_ [link] [comments]

Today’s typical home is wired for at least 100-amp service, and many are wired for twice that number. This makes sense given the multiplicity of modern appliances and electronics in a home. The demand is obviously higher if you have an electric stove/range, or an electric vehicle using a basic in-house Level 1 charger.

The need for power—and more of it—became clear when a neighbor who was having a modest addition put on the house asked me for some advice. The situation was this: the contractor told him that for various reasons, their 100+ A service would be cut to 50 A for a month or two during the construction. The reasons for this cutback were not clear, but it had something to do with cable capacity.

The question I was asked was simple enough: could they—a couple plus two children approaching teen years—manage on just 50 A and, if not, what steps could the take to minimize disruption? (Actually, the word my neighbor used was “survive” rather than “manage” but I feel that’s overly dramatic.)

The semi-quantitative assessment

My answer was also simple, as I gave the prudent engineering response “it depends” followed by “I’ll think about it and get back to you.” Then I set out to develop a firmer answer by doing some semi-quantitative assessment.

My first impulse was to check the web and, sure enough, there were plenty of apps for assessing house power needs. However, these required a detailed inventory of the loads which was more than I was ready to do. Then I thought I would create an Excel spreadsheet but soon realized that sort of analysis could easily become more precise than the problem merited. After all, my neighbor wanted a simple answer:

1. It’s no problem,
2. it’s definitely a problem, or
3. it’s a manageable “maybe” problem.

Instead, I took out my “back of the envelope” pad and decided to do some rough assessments, Figure 1.

Figure 1 This “back of the envelope” pad serves as a visible reminder that rough and imprecise input numbers should get appropriate analysis and not impute undeserved precision to the results. Source: Bill Schweber

I didn’t actually use this custom-made pad, but instead I kept it in front of me as a constant reminder that I should stick to estimates that were rough enough that they could be added up “in my head” on that pad. The reason for this simplicity is there are a lot of fuzzy numbers in the assessment.

For example, without knowing the make and model of various higher-current appliances such as the electric stove/range, any number I did use would likely have a ±10 to ±20% error band. Further, while the individual errors might cancel each other out to some extent they could also accumulate, resulting in a fairly large error band. In other words, random errors can aggregate either way.

The danger when using a spreadsheet is that soon you fall into a mental false-accuracy trap, since its available precision of more digits soon leads to the sense that there is corresponding accuracy as well, which is clearly not the case here (yes, I could restrict the cells to a few digits, but that’s another thing to do). It’s been my experience that it is very easy make the leap from rough estimate to a firm “you can bet on it” number, even if there is no basis for doing so; I’ve seen that happen in preliminary design review meetings many times when the project manager asks for some numbers.

Complicating the assessment, some of the larger loads such as the stove/range or microwave oven are under the direct control of the house occupants, while others such as heating system, refrigerator, and separate freezer control their own on/off cycles.

Numbers guide but don’t prove

I asked some questions about what was in the house, made a list, and went online to get a sense of how much current each uses. These rough estimates are for current consumption from a 120 VAC line; for those with 230 VAC lines, the current numbers should be cut in half, so that 50-A maximum would be 25 A:

1) Big loads you can’t control (these intermittent, asynchronous loads cycle on and off with unknown duty cycle; they may add up all at once, or hardly at all)

• Refrigerator/freezer: 6 A (will be higher for a few seconds, as the compressor kicks in)
• Separate outside freezer: 3 to 5 A, depending on outside temperature (same note as above)
• Oil-fired heating system: 5 A, temperature-dependent (same note as above)
• Electric water heater: 5 to 8 A

Total: around 20 A

2) Small loads (some you can control, some not; not an issue unless you are close to maximum limit

• Large TV: 1 to 2 A
• smaller screens: 0.5 A
• Various chargers: 0.5 A or less
• House lights: 0.5 A each
• House network boxes: 1 A

Total: 5 to 10 A

3) Bigger loads that you can control

• Clothes washer: 4 to 6 A
• Clothes dryer: 15 to 20 A
• Air conditioning: 8 to 10 A (but not a factor as this is a winter situation)
• Kitchen range top: 5 to 10 A, depending on model and temperature setting
• Kitchen oven: 8 to 12 A, depending on model and temperature setting
• Toaster Oven: 8 A
• Dishwasher: 9 to 12 A
• Microwave oven: 8 A
• Hair dryer: 10 to 12 A

Total: it depends on what you are using and when, but it adds up very quickly!

Conclusion: The loads you can’t control add up to around 25 A (all of these won’t be on 100% of the time) plus small loads of 5 to 10 A bring the total to 30 to 35 A, so the family will have about 15 to 20 amps of headroom on the loads that can be controlled. That’s doable but also cutting it close; you could have a case when just one additional modest load causes a droop and a brown-out of the supply voltage. That, in turn, brings on other operational problems in both motorized and all-electronic products.

Electrical service to older homes

As a curiosity, I checked out some older houses (1930 vintage) in the area, many of which are still occupied by descendants of the original families. Some of the present occupants said when the houses were built, they were outfitted with 30-A service and used knob-and-tube wiring rather than metal conduit or Romex (NM, or non-metallic sheathed) cable, Figure 2. While they have upgraded to 100+ A overs the years, some still have the knob-and-tube in the attic (not even close to code-approved now).

Figure 2 Early wiring used knob and tube insulation (a) which was replaced by (b) metal conduit (still in wide use) and (c) PVC-coated non-metallic sheathed cable, usually referred to as Romex. Sources: Arc Angel Electric Co., Meteor Electrical, D&F Liquidators

What’s your sense of the home-AC service situation? Have you ever been on a temporary or permanent limited-power budget at home? Have you ever had the corresponding “average load” versus “peak load” power-supply rating dilemma, either for line AC or with the DC supply in a product?

Bill Schweber is an EE who has written three textbooks, hundreds of technical articles, opinion columns, and product features.

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Reference

• Arc Angel Electric, “Understanding Knob and Tube Wiring: A Comprehensive Guide”

The post Can a household manage on just 50 amps? appeared first on EDN.

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After quantum computing, quantum communication is now stealing the headlines. Numana, a Montreal, Québec-based non-profit technology accelerator, has engaged Nokia and Honeywell Aerospace Technologies in its Kirq Quantum Communication Testbed to advance quantum-safe communication networks. While Nokia will contribute its advanced cryptographic network technologies, Honeywell is to share quantum encryption techniques.

Read the full story at EDN’s sister publication, EE Times.

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The post Canadian tech accelerator engages Nokia in quantum telecom testbed appeared first on EDN.

submitted by /u/Linker3000 [link] [comments]

After a while i really wanted to make a pcb (or let a manufacturer produce it for me, like jlcpcb) and going from 1 idea to the next, i settled on making this somewhat universal usable pqfp-100 adapter board. The Z80 cpu was something i already had laying arround for a project, but dint want to spend too much design time if it where a dud. Well, after designing the board, waiting a week or so. Soldering my first ever pqfp(or tqfp alike) it works ☺️ some wires to a generic z80 testboard and its walking the memory space for new instructions (all nop). Now i need to programm a eeprom and get that pio and sio working. The pcb should also work for a RTL8019AS-LF network ic i got for a retro pc build. submitted by /u/codeasm [link] [comments]

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Hello, I decided to make my first remote controlled car design on KiCad, please do provide feedback. I'm using components such as an NRF24 modules, an L289N motor driver, and a stand alone AT328P. The one thing that worries me greatly is I didn't add a connection to the reset pin on the AT328P, I left it floating, and upon further research, it is recommended to have a 10k resistor connected to 5V to the reset pin, otherwise it might reset randomly or not work. Is this true? I already ordered it so I'm afraid I can't do anything anymore if that's the case. Thanks! submitted by /u/Good-Marzipan4251 [link] [comments]

Here's a Microchip ATSAMD21G18A in a WeMos Arduino M0 clone, and here's the 48.007MHz clock brought out on a GPIO for inspection. That's the 32768Hz xtal oscillator multiplied by 1465 in the on-chip PLL. submitted by /u/DiscountDog [link] [comments]

I used a center tap transformer to step down the 110v to 9v AC, then I made a full bridge rectifier and smoothed it out with an electrolytic capacitor. Then, I used a Zener diode to regulate it to a smooth 5v. From my calculations, it has only a variation of .2%! Now I need a burner phone to test it on. submitted by /u/Programming_Cafe [link] [comments]

Wolfspeed Inc of Durham, NC, USA — which makes silicon carbide (SiC) materials and power semiconductor devices — says that it has received $192.1m in cash tax refunds from the advanced manufacturing tax credit under Section 48D (including $186.5m owed to it for both fiscal 2023 and fiscal 2024 taxes, as well as accrued interest). This comprises part of the approximately $1bn total Section 48D cash tax refunds that the firm expects to receive. As of the end of fiscal second-quarter 2025 (to 29 December 2024), Wolfspeed had accrued a total of $865m in Section 48D tax credits. The firm expects to receive more than $600m in cash tax refunds in fiscal 2026...

I finally decided to replace the tip of my Hakko FX-901 (the iron that runs on AA batteries). I’ve soldered all sorts of stuff with it over the years. submitted by /u/newsINcinci [link] [comments]

As I briefly noted back in mid-November, I ended up replacing my initial failed-experiment lithium battery-based portable power unit, Energizer’s PowerSource Pro Battery Generator:

with two EcoFlow successors, the smaller RIVER 2:

and this writeup’s subject, the DELTA 2, which I bought in claimed factory-refurbished condition (albeit, like the RIVER 2, also seemingly actually brand new) from EcoFlow via eBay in mid-September on sale (20% off list price) for $479 with an included 2-year extended warranty:

Why both? Or said another way, how do they differ? As you can likely already tell from the stock photo of each, the DELTA 2 is the huskier of the two:

	Dimensions	Weight
RIVER 2	9.6 x 8.5 x 5.7 in	7.7 lbs
DELTA 2	15.7 x 8.3 x 11 in (400 x 211 x 281 mm)	27 lbs (12 kg)

That said, EcoFlow puts the DELTA 2’s larger volume to good use with 4x the storage capacity: 1,024 Wh versus 256 Wh with the RIVER 2. The expanded front, rear and sides’ cumulative real estate also affords the DELTA 2 a larger and broader allotment of output power ports:

• Six AC (four two-prong, two three-prong with ground): 120V, 50Hz/60Hz, 1800W (along with 2200W at sub-120V per X-Boost technology, as detailed in my RIVER 2 coverage, and 2700W surge), pure sine wave, not simulated
• Two USB-A DC: 5V, 2.4A, 12W max
• Two USB-A “Fast Charge” DC: 5V @ 2.4A / 9V @ 2A / 12V @ 1.5A, 18W max
• “Cigarette lighter” car DC: 12.6V, 10A, 126W max
• Two DC5521 DC: 12.6V, 3A, 38W max (DC5525 adapter cable also included in kit)
• And two USB-C DC: 5/9/12/15/20V 5A, 100W max (unlike with the RIVER 2, however, these can’t do double-duty as charging input ports)

Unlike the RIVER 2, the DELTA 2’s storage capacity can be further expanded to between 2 kWh and (beyond) 3 kWh by tethering it to a separate DELTA 2, DELTA MAX or DELTA 2 MAX extra battery via its integrated XT150 connector:

That same XT150 connection also enables in-vehicle fast charging at up to 800W using the Alternator Charger, which I also now own ($319.20 on sale) and plan to install in my van soon:

Unfortunately, the very cool (and similar) looking PowerStream residential power unit, which I’m guessing also communicates with the DELTA 2 over XT150, isn’t currently available in the United States due to regulatory restrictions on plug-in grid solutions.

But the XT150-compatible Smart Generator is:

It’s a bit of an enigma, at least to me, given the company’s seeming heavy emphasis on solar and other renewable energy recharging sources. But hey, when the sun’s not shining but your battery’s drained, I suppose this gas-powered generator will do in a pinch instead. And although the product page implies that it only works with higher-capacity DELTA Pro and Max units, this company-published video confirms that it’s mainstream DELTA 2-compatible, too:

Whereas the RIVER 2’s XT60i DC charging input, usable with both solar and “cigarette lighter” car sources via cable adapters, is 110W max (for solar, specifically, 100W for car), the one in the DELTA 2 is beefier, supporting (again, for solar) an 11-60V and up to 15A/500W max input. Last September, I also bought two refurbished 220W second-generation EcoFlow solar panels, on sale at the time for $299 each inclusive of a two-year extended warranty:

which I’ll be cable-extending and in-parallel combining:

Stand by for coverage of them, along with hands-on impressions of the entire setup, to come.

What about AC charging? Although, as previously mentioned, the DELTA 2 has 4x the storage capacity of its RIVER 2 sibling, the charging speeds are surprisingly similar. Whereas the RIVER 2 will charge from 0% to full in 60 minutes, EcoFlow claims that the DELTA 2 will get to 80% in 50 minutes and completely full in 80 minutes. Photos taken during the first-time charging of my unit show that the initial charging rate:

automatically slows down as the full-charge threshold nears (note the input power variance):

and is eventually reached:

Here are those same first two charging segments captured by the wireless-tethered mobile app:

which is capable of simultaneously communicating with both of my EcoFlow devices:

assuming they’re both powered on at the time:

And what of generational enhancements and broader differences? As with the RIVER-to-RIVER 2 sequence I discussed in my recent coverage, EcoFlow also evolved the DELTA 2’s core battery technology from its precursor’s NMC (lithium nickel manganese cobalt), which is only capable of a few hundred recharge cycles before its maximum storage capacity degrades to unusable levels in realistic usage scenarios, to a LiFePO4 (lithium iron phosphate), also known as LFP (lithium ferrophosphate), battery formulation. Whereas the first-generation DELTA was guaranteed for only 500 recharge cycles, with the DELTA 2 it’s 3,000 (in both cases to 80+% of the original battery pack capacity), along with offering a boosted 5-year warranty.

And last September, EcoFlow launched not only the RIVER 3 family but also its first two DELTA 3 devices. The first, the DELTA 3 Plus, is now shipping as I write these words at the end of 2024:

Improvements versus the DELTA 2 predecessor include:

faster switching from wall outlet-sourced to inverter-generated AC (higher power, too) for more robust UPS functional emulation, as with the RIVER 3, along with improved airflow (leading to claimed 30 dB noise levels in normal operation), newer-generation denser 40135 batteries (translating to smaller dimensions and lighter weight, along with a boosted recharge cycle count to 4,000), expansion support up to 5 kWh, and even faster AC charging (sub-1 hour to 100%).

That all said, the DELTA 3 Plus has the same 1-kWh capacity as the non-Plus DELTA 2. What then, of the baseline DELTA 3 also briefly mentioned in last September’s unveiling, and supposedly available in October? Detailed specs are not yet public, at least to the best of my knowledge, as I submit this writeup. Instead (or in addition?), EcoFlow has stealth-launched the DELTA 3 1500:

whose two-color-option styling is reminiscent of the DELTA 2 but with boosted 1.5 kWh capacity and other tweaks. Specs are also scant for this device, but the Reddit crowd was able to dig up a user manual. My guess? EcoFlow is struggling to source enough lithium batteries (brand new DELTA 2 supplemental batteries are also MIA right now, although refurbs occasionally appear on eBay, the company website, etc.) and is dynamically evolving its product line in response.

In closing, after re-reading this piece, I realize that I may have come off as a bit (or more than a bit) of an EcoFlow “fanboy”. To be abundantly clear…I paid for all this gear myself (with no post-publication kickbacks), and the company doesn’t even know I’m doing these writeups. I just think that the products and their underlying technologies are quite cool. Agree or disagree? Let me know your thoughts in the comments!

—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

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The post EcoFlow’s Delta 2: Abundant Stored Energy (and Charging Options) for You appeared first on EDN.

Japan’s Mazda Motor Corp and Kyoto-based ROHM Co Ltd have commenced joint development of automotive components using gallium nitride (GaN) power semiconductors...

With the emergence of smaller models and techniques like distillation, will AI scaling stop, and we won’t need more compute power? Richard Ho, head of hardware at OpenAI, firmly believes that AI scaling will continue, and compute power will grow by orders of magnitude in the near future. During his keynote address at Synopsys Snug, he also talked about OpenAI’s in-house AI accelerator, issues related to AI clusters, and AI-empowered EDA tools.

Read the full story at EDN’s sister publication, EE Times.

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The post Will compute continue scaling in AI clusters? appeared first on EDN.