ultrasonic sensors though with lasers if you get shot in the eye your inclined to shut it, with invisible light you never know when its blinding you, guess it depends on the distance apart and the intensity of the light ...
though honestly I don't see why you couldn't do it with just normal light, even NFL players are not running faster than most light sensors
I don't use lasers myself, but the more I read about the potential for severe permanent optical damage the more I'm inclined to say that you want to keep things like this well away from children - and grownups too, I suspect.
Quote from: PeterH on Jan 22, 2012, 07:25 pmI don't use lasers myself, but the more I read about the potential for severe permanent optical damage the more I'm inclined to say that you want to keep things like this well away from children - and grownups too, I suspect.FFS. A typical laser pointer isn't going to cause permanent eye damage. If you're going to insist that it can then please provide a citation.
FFS. A laser pointer is obviously potentially dangerous . If you're going to insist that it cannot be dangerous under any circumstances then please provide evidence.
Possible more potentially damaging -- although not to the eye -- is that a regular pointer laser can overwhelm the eye with light, typically called flash blindness. If a person is walking a rocky path, operating machinery, a vehicle or aircraft, this temporary loss of vision could cause injury or disaster.
Both of your citations refer to high power lasers.
@atrodadWell. Not bad. gnd and from a ~ pin 10 is OK. External battery for the lase is OK. Can you tell me what type and number of the transistor you are using ? at the base ? I see a resistor and connect to the collector ? . Did you connect : 1. base limiting resistor.2. current limiting resistor. I know, sometime, it is hard to follow a schematic going to a breadboard.Here a picture of a typical transistor connection. Sorry for a bit "out of focus"In the picture, I use color code for my connection. Red is positive. Green is gnd / commun. I use a fiber optic transmitter. ( a IR led ) The limiting resistor is 68 ohms. The base transistor is 4.7 K. And the transistor is NPN - 2N3904 - EBC type. My circuit is connect to a FDTI USB board.