brianorca @ brianorca @lemmy.world

Posts

0

Comments

357

Joined

2 yr. ago

That's why most boat power systems use LiFePo4 (aka LFP) batteries instead of LiCoO2 like you phone battery. LFP is immune to thermal runaway, and can't burn even if it did overheat.

Boats with electric motors don't need a dedicated generator, as the motor can act as a generator when you put it in neutral. (If properly configured.)

Sailboats can operate at lower power levels, because their displacement hull is efficient at low speeds. (Where a planeing hull needs higher speeds to get more efficient.) When I had solar electric sail boat, I could motor at 2 knots with no wind using only 500w of solar without touching the battery. I usually ran it at 3.5 knots if there was no wind, which gave me lots of range on battery for a full day on the water.

They also have the sail as a primary power source when there's enough wind, so you don't always need the electric motor. Sometimes, if the wind is strong enough, you can use the water turning the propeller to generate electricity to charge the battery. Or if the wind is light, you can use the motor to add more speed than sail alone, using less battery than using electric alone.

They have one other advantage: unit price. But Lithium is rapidly catching up, and is already better if you calculate price per lifetime charge cycle.

There a whole branch of quantum mechanics research that's trying increasingly complicated ways of not looking at the particles while trying to sneak a look.

Blacktip Reef sharks, like some others such as great white and hammerhead, are "obligate ram ventilators" because forward movement is the only way they can push water over their gills. Nurse sharks and some others are able to close their mouth and pump water to the gills while stationary.

In AC, diodes work half the time, every 1/60 second. The "good" LEDs will have circuitry to fully rectify the AC into DC, drop the voltage properly, and smooth the peaks and valleys, so they will be continuously lit. So the cheap LED Christmas lights might have a slight flicker, and the good ones are steady. (Or get fancy with chasing colors, etc.)

All of that happens inside each of the "bulb" enclosures, or sometimes in a box at one end, so it technically doesn't matter which end they are getting electricity from, since the socket at the far end is still just connected in parallel to the plug at the near end. (Otherwise you wouldn't be able to link them together.)

It's just a really bad dangerous idea to reverse them.

It's also checking your other traffic. (Since Cloudflare handles traffic for so many companies.) Are you visiting other sites in a realistic fashion, or are you doing 99% of your traffic trying to do one thing over and over.

Others mention the mouse motion, and monitoring your other traffic to similar sites. When it shows the checkbox, it has already determined you are probably human. If you had suspicious activity, they will give you more advanced tests instead of just a checkbox.

It would still work. But it is VERY dangerous. 1. The far end of the light string will now have exposed metal prongs that are energized at 120v, which can be fatal. 2. If the other end gets plugged into a socket, there is a 50% chance it will be a different circuit on a different phase, which can create a 240v direct short, across a wire that has no properly sized circuit breaker. 3. Using it to plug a generator into your house during a power outage can kill electrical workers trying to fix the outage if you fail to open your circuit breakers.

If someone can't make the own cord, what's the chance they know how vital it is to flip the breaker?

Two things: 1: there's a high chance you do cross live and neutral, or even live and live on different phases. 2: using it to plug in a generator to power your house can kill electrical workers who are trying to restore a power outage. (If you fail to open your circuit breaker.)

It also falls off too easily. My favorite for this use case is black Gorilla tape. Like duct tape but thicker.

No, this is about the fake phishing emails that are released inside the network to test user response. If clicked, they report to IT which users need more training.

My guess is that's how high it needs to be for the sewer to flow in the right direction.

This is because NSA has two roles: eavesdropping on foreign adversaries, and protecting our internal systems from adversaries. Under the first role, they might introduce an exploit known only to themselves. Under the second, they help protect US systems from exploits known to others.

A defibrillator is for a heart that is in fibrillation, which is a jumbled, ineffective vibration, NOT a flat line.

True, but it especially applies to drowning because they are under the water, unable to get air to make any noise.

Spoilers in Connect are not readable when I click them. (White on white) Unless I first select the post so the background in grey.

It's because ducks are actually going someplace, while eagles are soaring over a thermal, trying to stay in one spot to watch for food.