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Search: Posts Made By: dougmc
Forum: Electronics, Lighting, & Gadgets 07-04-15, 11:09 PM
Replies: 785
Views: 213,580
Posted By dougmc
That light is shipped with a 2s battery -- so it...

That light is shipped with a 2s battery -- so it maxes out at 8.4 volts. In general, those lights will work fine on a 3s battery (though this is not 100% certain), so 12.6 volts, and a car system...
Forum: Electronics, Lighting, & Gadgets 05-31-15, 01:28 AM
Replies: 61
Views: 20,193
Posted By dougmc
It also makes the business end of the light not...

It also makes the business end of the light not *just fall off* like the Planet Bike Super Flash will do it you don't secure it with tape, rubber band or zip tie.
Forum: Commuting 05-12-15, 10:39 PM
Replies: 55
Views: 9,430
Posted By dougmc
No. Lux will just tell you how bright one spot...

No. Lux will just tell you how bright one spot is, typically the very brightest spot, in the middle of the bright spot made by the light.

But that depends on how far the surface is from the light...
Forum: Commuting 05-12-15, 12:51 PM
Replies: 55
Views: 9,430
Posted By dougmc
They're related, but they measure different...

They're related, but they measure different things.

Lumens measures total light (adjusted for how sensitive the human eye is to each wavelength of light, but we can generally ignore that part.)
...
Forum: Electronics, Lighting, & Gadgets 03-07-15, 08:34 PM
Replies: 29
Views: 1,762
Posted By dougmc
I didn't say or even imply that it did. I also...

I didn't say or even imply that it did. I also invoked the largely tongue-in-cheek suggestion that number of blades in a razor blade might follow a similar progression, to further suggest that it...
Forum: Electronics, Lighting, & Gadgets 03-04-15, 10:35 PM
Replies: 29
Views: 1,762
Posted By dougmc
The whole thing is one big heat sink, and it's...

The whole thing is one big heat sink, and it's likely used with a 15+ mph or so breeze blowing on it (i.e. you're riding.) It probably wouldn't get excessively hot unless you stopped for a few...
Forum: Electronics, Lighting, & Gadgets 03-04-15, 08:26 PM
Replies: 29
Views: 1,762
Posted By dougmc
8.4 volts is certainly right for a fully charged...

8.4 volts is certainly right for a fully charged 2s battery.

As for plugging in an ammeter ... that would require that somebody actually buy this monstrosity. But 1 amp on high is probably too...
Forum: Electronics, Lighting, & Gadgets 03-04-15, 07:37 PM
Replies: 29
Views: 1,762
Posted By dougmc
Let's look at this another way ... One amp...

Let's look at this another way ...

One amp at 8.4 volts is 8.4 watts. 3000 lumens/8.4 watts = 357 lumens/watt, which is significantly higher than the theoretical limit for a white LED...
Forum: Electronics, Lighting, & Gadgets 02-26-15, 06:48 PM
Replies: 29
Views: 1,762
Posted By dougmc
This light/USB charger is the worst example of...

This light/USB charger is the worst example of lumen inflation I've ever seen (http://www.frys.com/product/8299556) -- they claim 2300 lumens, but the reality is perhaps 10 to 15 lumens.

That...
Forum: Electronics, Lighting, & Gadgets 02-26-15, 10:59 AM
Replies: 29
Views: 1,762
Posted By dougmc
3000 lumens tends to mean around 30 watts, and...

3000 lumens tends to mean around 30 watts, and six 3000 mAh 18650 cells could produce 30 watts for about 2.25 hours. To get four hours out of it, they'd have to reduce the lumens somewhat or be...
Forum: Electronics, Lighting, & Gadgets 02-26-15, 10:21 AM
Replies: 29
Views: 1,762
Posted By dougmc
Moore's laws for lights?

First we had Moore's laws for CPUs, where number of transistors increased exponentially, then it was hypothesized that it might also apply to razor blades (http://www.economist.com/node/5624861) ......
Forum: Advocacy & Safety 12-19-14, 08:00 AM
Replies: 59
Views: 2,216
Posted By dougmc
The Planet Bike Blaze 2w? It's on the high end...

The Planet Bike Blaze 2w? It's on the high end of "be seen" lights and the low end of "help me see" lights.

I don' t know why you don't trust them, but the quality on this specific light is good...
Forum: Advocacy & Safety 12-11-14, 05:20 PM
Replies: 64
Views: 3,721
Posted By dougmc
But you told us that you didn't stop. Right? Or...

But you told us that you didn't stop. Right? Or are you going to tell the judge something other than what you told us? (Well, the original poster said he didn't stop, not you.)

And as Coal...
Forum: Advocacy & Safety 12-11-14, 01:17 PM
Replies: 64
Views: 3,721
Posted By dougmc
While it's true that most people do rolling stops...

While it's true that most people do rolling stops when there's not traffic to yield to ... the law requires a complete stop.

So when you show up to contest the ticket, you can either go "Well,...
Forum: Advocacy & Safety 12-11-14, 12:56 PM
Replies: 59
Views: 2,216
Posted By dougmc
That must be specific to whatever lights you've...

That must be specific to whatever lights you've got -- in general, flashing modes use the battery up considerably slower than steady on modes, for example this light lasts 5 hours on high, 12 hours...
Forum: Advocacy & Safety 11-19-14, 04:37 PM
Replies: 51
Views: 2,575
Posted By dougmc
Bail is not required when somebody is sued --...

Bail is not required when somebody is sued -- that's a civil case.

Bail is only for criminal cases, and in general only for the more serious ones -- moving violations may be a criminal matter in...
Forum: Electronics, Lighting, & Gadgets 11-13-14, 02:52 PM
Replies: 22
Views: 1,542
Posted By dougmc
The small difference is largely due to how power...

The small difference is largely due to how power needed to overcome air resistance is proportional to speed cubed, and at speed most power goes into overcoming air resistance. Because of that,...
Forum: Electronics, Lighting, & Gadgets 10-31-14, 09:33 AM
Replies: 785
Views: 213,580
Posted By dougmc
After seeing the $15 one, I ordered another. It...

After seeing the $15 one, I ordered another. It arrived yesterday ... which had it arriving in two weeks.

Things I've ordered from China in the last year or so are getting here more quickly...
Forum: Advocacy & Safety 10-25-14, 02:06 PM
Replies: 132
Views: 5,898
Posted By dougmc
If you just lose your alternator, sure. If you...

If you just lose your alternator, sure. If you lose your water pump (which you normally do when your car only has one belt) ... most cars will overheat (which tends to mean expensive damage if you...
Forum: Electronics, Lighting, & Gadgets 10-16-14, 11:21 AM
Replies: 785
Views: 213,580
Posted By dougmc
Well, except that the title was "Black Solarstorm...

Well, except that the title was "Black Solarstorm 5000LM 2X CREE XML U2 LED Front Bicycle Bike Headlight Headlamp | eBay...
Forum: Advocacy & Safety 10-15-14, 11:40 PM
Replies: 132
Views: 5,898
Posted By dougmc
There is an electric motor connected to steering...

There is an electric motor connected to steering system, and so is your steering wheel. If you lose power, you can still steer, though with considerable effort.

However, if the circuit/computer...
Forum: Advocacy & Safety 10-14-14, 04:01 PM
Replies: 132
Views: 5,898
Posted By dougmc
Don't you already? Your car already has...

Don't you already? Your car already has microprocessors and such that if they failed in the wrong way could end your life. The "runaway throttle" problems that some cars have had have been computer...
Forum: Advocacy & Safety 10-14-14, 03:12 PM
Replies: 132
Views: 5,898
Posted By dougmc
I do realize that you're attempting to engage in...

I do realize that you're attempting to engage in some clever word play here, but just to be clear, I was using the term "imagine" in the second way here --


Now, it is indeed a forward looking...
Forum: Advocacy & Safety 10-14-14, 11:31 AM
Replies: 132
Views: 5,898
Posted By dougmc
I imagine that ultimately the self-driving cars...

I imagine that ultimately the self-driving cars will *still* handle that better than a human -- they'll see the car move a tiny amount before it backs up and anticipate that it might back out...
Forum: Advocacy & Safety 09-26-14, 12:11 PM
Replies: 10
Views: 1,160
Posted By dougmc
Cops usually won't argue with you on *any one*,...

Cops usually won't argue with you on *any one*, not just this one.

That said, sometimes they'll respond favorably to being shown the exact wording of the law -- but I'd expect most of them to get...
Showing results 1 to 25 of 500

 
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