Wait, if they're already blasting it full on, why are they using PWM at all? I was going to use a TLC5940...
There's part of your answer - they use PWM controllers because they can be controlled via a serial interface and they don't require a resistor per segment. The actual PWM part is a bonus. You've seen the 'throbby' turn signals, right?
A cap would work, but they're notoriously unreliable in high heat/extreme conditions, they're expensive, bulky, and it would have to be a fairly large cap to provide a slow enough rise time at typical LED currents. The other downside is that the cap would likely also result in an equally long fall time. Depending on the circuit (assuming no constant-current source) the inrush currents could be fairly high (a discharged cap is like a short circuit until it charges).
A better solution would be to modify the existing PWM code (as the parent poster mentions) to ramp the brightness up instead of blasting it full-on. This is done in switching supplies to provide what's called 'soft start'. Here's an example using a Microchip embedded processor.
Maybe it's just my old eyes, but I find the wicked-fast 'rise time' of LEDs in traffic lights and auto stoplights startling. To me it's actually a distraction to be startled every time someone hits their brakes. I'll probably get used to it as they become more prevalent.
What about the HAM radio guys who put their callsigns on their plates? Oh noes, they have a hobby and used a plate instead of a less readable bumper sticker. What a sense of entitlement they must have.
At least in Virginia you must have an amateur radio license (duh) and amateur radio equipment installed in your car to qualify for a ham plate. The rationale is that if a police officer needs comms, they can rely on anyone with a ham plate. After all, the first purpose of amateur radio existing (as codified in Title 47, Part 97.1a):
"Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications. "
Are you familiar with the works of H.R. Giger? I just got a mental image of a a cow with a steampunk-esque tank on its back, contentedly munching on grass.
I think the majority of the problems were due to a bad batch. I ordered 5 last November and 3 were DOA (USB/network issues). The 3 Newark sent as replacements were good; good enough to play 1080p video streamed over the LAN with raspbmc and not reboot yet (months and counting).
I made the Darth Vader comment - it's from the air leaving the little exit hole on the mask. Trying to talk with the CPAP on makes you sound more like Zuul (at 00:13), not Vader.
Re: the fan ramp-up sound - I think what you might be hearing is the fan returning to normal speed after slowing when you exhale. All of the CPAPs I've used with that option have a setting to turn that off. I prefer no initial pressure ramp-up and no pressure release when I exhale (it makes the mask stay in place better).
If the noise still bothers you, you can try putting the machine on the floor or under the bed. You can also use those foam in-ear earplugs.
According to NOAA, we should be nearing the peak of a solar cycle. Sadly, it's been a terrible 'peak' for radio propagation. I've only got so many 11 year cycles left to live - come on, Sun, give me a break!
I scanned that article and found no reference to why 13.56 MHz is a 'magic frequency' with regard to methane. With a wavelength of 22.1+ meters, it wouldn't have any sort of resonance with methane. In fact, the article goes on to talk about bond lengths and distances on the 10^-10m range, which is more like laser frequencies. My bet is that 13.56 MHz was chosen because it is a very popular ISM frequency for which there is plenty of COTS hardware.
Any decent prospective partner would understand. It's better to sound a little like Darth Vader than snore like a freight train.
Funny story - a female friend, my wife and I spent 3 weeks in Scotland, and this was the first time I'd taken my CPAP on a trip. We spent the night in Edinburgh on Prince's Street (the Old Waverly, I think it was). I was relegated to the outer bedroom, and the ladies got the one with the two beds.
I was shocked out of my mind the next morning when I opened my eyes to see some guy in the room with me looking like he had the creature from Alien on his face. I hadn't realized when I went to bed that there was a full-length mirror on the wall next to the bed. Naturally that was me in my CPAP mask.
If he has sleep apnea, it can lead to a marked increase in his risk for heart attacks. With severe sleep apnea, your body senses your blood O2 saturation dropping and wakes you up in a panic thinking you're dying (seriously). That sort of 'night of 1000 deaths' leads to high cortisol levels and all sorts of other nasty things. I assume you probably already have, but urge him to at least have a sleep study done - that may show him that a simple CPAP machine can return his sleep patterns to normal. It quite literally saved my life.
The average (median) American eats 1.03 kg per day...
That's per per meal, right? ~sarcasm (Also a healthy dose of guilt - I'm one of those that would burn for years if you stuck a wick in me).
1.03 kg/day with a 70/30 split for calories from carbs+protein vs fat comes to 4944 calories/day. There must be a heck of a lot of fiber in their numbers.
(164.8 g of fat * 9 cal/g = 1483.2 cal from fat. 865.2 g protein or carbs * 4 cal/g = 3460.8 cal from protein or carbs).
Slashdot Mirror
The President is required BY LAW to present a budget to Congress "On or after the first Monday in January but not later than the first Monday in February of each year..."
He has failed to submit a budget on time four out of the last five years.
From the same article, above: "The Constitution, the supreme law of the land, states clearly, “he shall take Care that the Laws be faithfully executed.”
He clearly is not abiding by either of those requirements.
What makes you so sure that we didn't shoot it down?
Because these guys have observed and photographed it.
Surely you mean 1999?
Uh, no, it's not banned. The only thing it can't contain are the lungs (or lights), since they are extremely perishable.
Lungs are a no-no
Haggis vendor 1
Haggis vendor 2
Haggis vendor we use for our Burn's Night
Canned haggis (it's not bad, but it ain't traditional)
Lungless, low-fat haggis (ick!)
They must be engaged with a enemy with which we are at war as declared by Congress .
So that would be no one since WWII?
...they can recognize hundreds of molecules, and subtitles of radio spectra...
What are the radio spectra subtitles saying? Are they in Japanese?
Wait, if they're already blasting it full on, why are they using PWM at all?
I was going to use a TLC5940...
There's part of your answer - they use PWM controllers because they can be controlled via a serial interface and they don't require a resistor per segment. The actual PWM part is a bonus. You've seen the 'throbby' turn signals, right?
A cap would work, but they're notoriously unreliable in high heat/extreme conditions, they're expensive, bulky, and it would have to be a fairly large cap to provide a slow enough rise time at typical LED currents. The other downside is that the cap would likely also result in an equally long fall time. Depending on the circuit (assuming no constant-current source) the inrush currents could be fairly high (a discharged cap is like a short circuit until it charges).
A better solution would be to modify the existing PWM code (as the parent poster mentions) to ramp the brightness up instead of blasting it full-on. This is done in switching supplies to provide what's called 'soft start'. Here's an example using a Microchip embedded processor.
Not to mention, traffic lights.
Maybe it's just my old eyes, but I find the wicked-fast 'rise time' of LEDs in traffic lights and auto stoplights startling. To me it's actually a distraction to be startled every time someone hits their brakes. I'll probably get used to it as they become more prevalent.
I have a pic somewhere of the Virginia equivalent - the car was parked outside my office.
What about the HAM radio guys who put their callsigns on their plates? Oh noes, they have a hobby and used a plate instead of a less readable bumper sticker. What a sense of entitlement they must have.
At least in Virginia you must have an amateur radio license (duh) and amateur radio equipment installed in your car to qualify for a ham plate. The rationale is that if a police officer needs comms, they can rely on anyone with a ham plate. After all, the first purpose of amateur radio existing (as codified in Title 47, Part 97.1a):
"Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications. "
Are you familiar with the works of H.R. Giger? I just got a mental image of a a cow with a steampunk-esque tank on its back, contentedly munching on grass.
Current World population: 7.063 Billion.
Current population of the US and Mexico: 315,245,000 and 112,336,538, respectively.
Total population of the US and Mexico: 427,581,538
7.063 billion * 6% = 423,780,000
Doesn't that add up?
I think the majority of the problems were due to a bad batch. I ordered 5 last November and 3 were DOA (USB/network issues). The 3 Newark sent as replacements were good; good enough to play 1080p video streamed over the LAN with raspbmc and not reboot yet (months and counting).
According to Wikipedia, the US interest in bioweapons started around 1918.
An interesting coincidence given that the world has just been subjected to the deadliest viral pandemic in history, no?
It killed between 50 and 100 million people - 3% to 6% of the world's population at that time.
If that happened today, it would kill the equivalent of every living soul in the United States and Mexico. Sobering, huh?
Develop a strain of Bacteria that causes chronic flatulence.
THAT is harassment.
... or the solution to our dependence on fossil fuels.
I made the Darth Vader comment - it's from the air leaving the little exit hole on the mask. Trying to talk with the CPAP on makes you sound more like Zuul (at 00:13), not Vader.
Re: the fan ramp-up sound - I think what you might be hearing is the fan returning to normal speed after slowing when you exhale. All of the CPAPs I've used with that option have a setting to turn that off. I prefer no initial pressure ramp-up and no pressure release when I exhale (it makes the mask stay in place better).
If the noise still bothers you, you can try putting the machine on the floor or under the bed. You can also use those foam in-ear earplugs.
Good luck!
I'll agree with most of what you say as long as you don't try to take away my intelligent, tasty bacon.
According to NOAA, we should be nearing the peak of a solar cycle. Sadly, it's been a terrible 'peak' for radio propagation. I've only got so many 11 year cycles left to live - come on, Sun, give me a break!
I scanned that article and found no reference to why 13.56 MHz is a 'magic frequency' with regard to methane. With a wavelength of 22.1+ meters, it wouldn't have any sort of resonance with methane. In fact, the article goes on to talk about bond lengths and distances on the 10^-10m range, which is more like laser frequencies. My bet is that 13.56 MHz was chosen because it is a very popular ISM frequency for which there is plenty of COTS hardware.
It looks to me like a great incentive for parents to try as hard as possible to get their child employed; free money once they're caught!
Any decent prospective partner would understand. It's better to sound a little like Darth Vader than snore like a freight train.
Funny story - a female friend, my wife and I spent 3 weeks in Scotland, and this was the first time I'd taken my CPAP on a trip. We spent the night in Edinburgh on Prince's Street (the Old Waverly, I think it was). I was relegated to the outer bedroom, and the ladies got the one with the two beds.
I was shocked out of my mind the next morning when I opened my eyes to see some guy in the room with me looking like he had the creature from Alien on his face. I hadn't realized when I went to bed that there was a full-length mirror on the wall next to the bed. Naturally that was me in my CPAP mask.
If he has sleep apnea, it can lead to a marked increase in his risk for heart attacks. With severe sleep apnea, your body senses your blood O2 saturation dropping and wakes you up in a panic thinking you're dying (seriously). That sort of 'night of 1000 deaths' leads to high cortisol levels and all sorts of other nasty things. I assume you probably already have, but urge him to at least have a sleep study done - that may show him that a simple CPAP machine can return his sleep patterns to normal. It quite literally saved my life.
Look up Polymerase Chain Reaction - they call it amplification, and it is very legit.
The average (median) American eats 1.03 kg per day...
That's per per meal, right? ~sarcasm (Also a healthy dose of guilt - I'm one of those that would burn for years if you stuck a wick in me).
1.03 kg/day with a 70/30 split for calories from carbs+protein vs fat comes to 4944 calories/day. There must be a heck of a lot of fiber in their numbers.
(164.8 g of fat * 9 cal/g = 1483.2 cal from fat. 865.2 g protein or carbs * 4 cal/g = 3460.8 cal from protein or carbs).