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Laser beam detector

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shahnaz

New Member
hi guys,

i am currently doing a project!kindly requesting for help!!
i need a circuit to detect the laser beam from a laser pointer and then it gives the signal to a digital counter that displays counting in a 7 segment display!
i have the laser pointer circit!
i wan to know how to build the circuit that is going to be around 3meter away from my pointer. Everytime this circuit detects the laser the counter has to count up!

thanks in advance!!
 

Sceadwian

Banned
The laser beam from a typical laser pointer is nothing more than red light, you could use a CDS sensor, or any photo diode or photo transistor sensative to the wavelength of the laser.
 

HarveyH42

Banned
I once used an IR receiver module, and pulsed the laser pointer at ~38kHz. Worked at about 40 feet, but was very tough to get the laser pointed at the receiver module, as it wasn't as bright. At 3 meters, you shouldn't have much trouble lining it up. I used the IR module, because it was for outdoors, and it helps to avoid false triggers. As mentioned above, you could use most any sensors, use a tube to shield out unwanted light sources. There are tons of Laser-tripwire projects on the web, shouldn't be hard to find one that suits you. Mentioned the IR module, as its not something you will find (haven't looked lately though). I used microcontrollers, mostly because I had just started to learn them. A 555 could be used to drive the laser pointer. The IR receiver needs 5 volts (works on a little less), and normally High, if not receiving a signal (in your case, blocked), which works out good for you.

The counter and display, should be easy enough to find on the web, been done for decades. Been using microcontrollers for a few years, and seldom look back...
 

shahnaz

New Member
Oh thks for the information! What are the other problems the receving circuit may face other then the light disturbance?N ya is there any other circuit or IC chip that will give me a output to show the battery power. i am using a 3 1.5v battery for the laser pointer circuit and i want a LED bar to show the power of the battery. I heard there is a chip but couldn't find it!!!

THKS ONCE AGAIN!!!!
 

MikeMl

Well-Known Member
Most Helpful Member
...N ya is there any other circuit or IC chip that will give me a output to show the battery power. i am using a 3 1.5v battery for the laser pointer circuit and i want a LED bar to show the power of the battery. I heard there is a chip but couldn't find it!!!
Sounds to me that this is case where the LED bargraph indicator circuit would draw more power from the battery than the circuit it is monitoring. The bargraph would show how fast the bargraph is killing the batteries :D
 

crutschow

Well-Known Member
Most Helpful Member
If your bargraph only operated when you pushed the pointer button, then its drain might be acceptable, especially if you use high brightness LEDs at a low current level (a couple mA or so). You should be able to use an LM3914 for this.
 
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