4 ms·

I REALLY doubt the "Good stopping effect". That's the same as the flashlights with "intruder stopping" strobe. They claim 16J. Well, a typical - Germany Legal

I REALLY doubt the "Good stopping effect". That's the same as the flashlights with "intruder stopping" strobe. They claim 16J. Well, a typical - Germany Legal - Airsoft gun has 7.5J, so we're talking about toy-level of energy. Now, looking at some 9mm ammo, you have around 500-570J depending on type - Ball vs. Hollow Point. Yeah, it's very clear to me, what I want to use if I have to defend myself.

semi-extrinsic 5y ago
Comparing impact energy between a flat and a pointed object is meaningless. A five-year-old in a pillow fight will put substantially more than 16J into your body.
- glenstein 5y ago
  I agree, and I feel like this is a critical point being overlooked. A pillow and a point of a stick can apply the same amount of force, with completely different effects.
robbedpeter 5y ago
A 50-100k lumen flashlight would be a better defense, cost less, and possibly be more fun (for night fishing, too!)
- Blammar 5y ago
  LED flashlights don't go up to 100k lumens to my knowledge. If you need extreme intensity, you'll have to use a solid state laser. A 10w handheld laser would be an effective defense, but you should wear bandstop glasses at the laser frequency. A beam spreader would also make it easier to aim and still nearly as effective.
  - jaggederest 5y ago
    This little fella here: https://www.imalentlight.com/imalent-ms18-led-flashlight-cree-xhp70-2-led-max100000-lumens-intelligent-charging-for-outdoor-search-light.html https://www.imalentlight.com/imalent-ms18-led-flashlight-cre...
    - robbedpeter 5y ago
      Strobing it at an intruder would possibly take them down. Epileptic criminals would be screwed. https://en.m.wikipedia.org/wiki/LED_incapacitator https://en.m.wikipedia.org/wiki/LED_incapacitator $600 isn't too bad, could do wonders for noisy neighbors, too!
    - Blammar 5y ago
      That's marketing hype. From the CREE datasheet at https://cree-led.com/media/documents/ds-XHP702.pdf https://cree-led.com/media/documents/ds-XHP702.pdf, each LED runs between 1500 to 2000 lumens. That flashlight has 18 LEDs, so 36k lumens at the most. Also, for the rated brightness, each LED has to be run at 12VDC 2.4 amps or ~30 watts. The thing has 8 21700 cells at ~3.7v each 4Ah. So the cells are probably wired in a 2x4 configuration giving 7.5v and a total of 32Ah. Current draw for the LEDs is higher at lower voltage, so it's 12/7.5*2.4A = ~3.8A per LED or ~70 amps total draw. So yeah the numbers show it's feasible to run the 18 cells at full current for about 25 minutes and get the 36k lumens. The heat dissipation will be about half a kilowatt, so quite likely the flashlight will get too hot to hold fairly quickly, even with its heat-pipe cooling. I'm not an EE, I'm just channeling my long ago physics class on circuitry, so I could be egregiously wrong in places.
      - jaggederest 5y ago
        They usually run them through power regulation circuitry (a boost converter or the digital equivalent) and overdrive the LEDs, maybe into the 24v+ range. The "turbo" mode usually only runs for a few seconds at most, and is where they derive the high lumen numbers from. With this kind of flashlight you have to use unprotected lithium ion cells because they far exceed what the protection circuitry will let you do. Also related to their tendency to go kaboom if set up wrong.
  - sgt 5y ago
    Somehow I feel it's more humane to kill an intruder than to blind him.
    - Blammar 5y ago
      Both are terrible things to do. However, doing the second may be more of a deterrence in the long run. On the gripping hand, holding a laser potentially makes you more of a target than if you use a flash-suppressing sniper rifle. It's best not to be in the situation in the first place.

semi-extrinsic 5y ago

Comparing impact energy between a flat and a pointed object is meaningless. A five-year-old in a pillow fight will put substantially more than 16J into your body.

glenstein 5y ago
I agree, and I feel like this is a critical point being overlooked. A pillow and a point of a stick can apply the same amount of force, with completely different effects.

robbedpeter 5y ago

A 50-100k lumen flashlight would be a better defense, cost less, and possibly be more fun (for night fishing, too!)

Blammar 5y ago
LED flashlights don't go up to 100k lumens to my knowledge. If you need extreme intensity, you'll have to use a solid state laser. A 10w handheld laser would be an effective defense, but you should wear bandstop glasses at the laser frequency. A beam spreader would also make it easier to aim and still nearly as effective.
- jaggederest 5y ago
  This little fella here: https://www.imalentlight.com/imalent-ms18-led-flashlight-cree-xhp70-2-led-max100000-lumens-intelligent-charging-for-outdoor-search-light.html https://www.imalentlight.com/imalent-ms18-led-flashlight-cre...
  - robbedpeter 5y ago
    Strobing it at an intruder would possibly take them down. Epileptic criminals would be screwed. https://en.m.wikipedia.org/wiki/LED_incapacitator https://en.m.wikipedia.org/wiki/LED_incapacitator $600 isn't too bad, could do wonders for noisy neighbors, too!
  - Blammar 5y ago
    That's marketing hype. From the CREE datasheet at https://cree-led.com/media/documents/ds-XHP702.pdf https://cree-led.com/media/documents/ds-XHP702.pdf, each LED runs between 1500 to 2000 lumens. That flashlight has 18 LEDs, so 36k lumens at the most. Also, for the rated brightness, each LED has to be run at 12VDC 2.4 amps or ~30 watts. The thing has 8 21700 cells at ~3.7v each 4Ah. So the cells are probably wired in a 2x4 configuration giving 7.5v and a total of 32Ah. Current draw for the LEDs is higher at lower voltage, so it's 12/7.5*2.4A = ~3.8A per LED or ~70 amps total draw. So yeah the numbers show it's feasible to run the 18 cells at full current for about 25 minutes and get the 36k lumens. The heat dissipation will be about half a kilowatt, so quite likely the flashlight will get too hot to hold fairly quickly, even with its heat-pipe cooling. I'm not an EE, I'm just channeling my long ago physics class on circuitry, so I could be egregiously wrong in places.
    - jaggederest 5y ago
      They usually run them through power regulation circuitry (a boost converter or the digital equivalent) and overdrive the LEDs, maybe into the 24v+ range. The "turbo" mode usually only runs for a few seconds at most, and is where they derive the high lumen numbers from. With this kind of flashlight you have to use unprotected lithium ion cells because they far exceed what the protection circuitry will let you do. Also related to their tendency to go kaboom if set up wrong.
- sgt 5y ago
  Somehow I feel it's more humane to kill an intruder than to blind him.
  - Blammar 5y ago
    Both are terrible things to do. However, doing the second may be more of a deterrence in the long run. On the gripping hand, holding a laser potentially makes you more of a target than if you use a flash-suppressing sniper rifle. It's best not to be in the situation in the first place.