Looks like the guy came up with a cool product. Wonder if he ever found a buyer?

I went back and looked at the vid comments. Apparently, not.

No, doesn't look like it. I posted a comment a few weeks ago but he hasn't responded.

 

I think it's a good application for a microcontroller, and will give it some thought.

 

I think it's a good application for a microcontroller, and will give it some thought.

If you come up with any ideas I'd really appreciate it if you would post them or PM me. Sounds like what you are thinking (with a microcontroller) may be a little more advanced than what I was planing but still would like to hear your ideas if you pursue it.

Sounds like there are 1" LDR's out there so I'm going to give that a try if I can find one. If that ends up being to small I'll try some of the ideas suggested here. I think I'm going start with just controling a solinoid and some LED's using the LDR a mosfet and then a relay.

 

Much easier to use a solar panel.

 

Much easier to use a solar panel.

Thanks for the reply Danny. Could you please explain in a little more detail how a solar panel could work in my project? I need to activate a relay almost instantly after a laser hits the solar panel.

I appreciate your help!

Bri

 

You could try using a thick disk of clear acrylic plastic, sand the hell out of it on both sides, this is your target light diffuser.
Mount a photo-transistor behind it , about 1 radius away from the disc, inside a light shielding can.

You are not going to get much of a signal out of this, it's going to need an amplifier with high-pass characteristics to create a pulse on the leading edge of the light hit- not terribly difficult, but much more complicated than an LDR.

Beware - lot's of other light sources contain high frequency pulses, LED lights, CFL's etc.
The best concept would use a modulated light source and a band-pass filter to limit sensitivity to only the desired light source.
The simple LDR system also has poor immunity to ambient light conditions.

Another idea is to use a 38 Khz IR remote control receiver, these still have some sensitivity to visible wavelengths, you would need to modulate your laser at 38 Khz.

 

If you come up with any ideas I'd really appreciate it if you would post them or PM me. Sounds like what you are thinking (with a microcontroller) may be a little more advanced than what I was planing but still would like to hear your ideas if you pursue it.

Sounds like there are 1" LDR's out there so I'm going to give that a try if I can find one. If that ends up being to small I'll try some of the ideas suggested here. I think I'm going start with just controling a solinoid and some LED's using the LDR a mosfet and then a relay.

Have a look at this. http://www.allaboutcircuits.com/projects/laser-detection-system-using-a-picaxe/

 

Have a look at this. http://www.allaboutcircuits.com/projects/laser-detection-system-using-a-picaxe/

Cool! Thanks for writing the article! Very detailed, all the way down to the part numbers... You did a excellent job explaining everything. Sometimes when I read an article such as this the author looses me half way through. However, even with my very limited electronics experience I think I can build one of these! (Well, with the exception of the PICAXE microcontroller programing.... Unless I can just copy and paste lol. I read your first article on the PICAXE microcontrolers and saw it was designed so a child could program them. But unfortunately I'm feeling like my dad did when I tried to explain how to program his VCR years ago ). One of the things in your article that really helps me out a lot (and I learn from this) is to be able to see the actual physical circuit along with the schematic.

I do have a couple questions if you have the time.

1.) What is the purpose of the capacitor?

2.) How many amps can this PICAXE micro controller handle?

3.) Are the C.1,C.2, C.3 etc. like dry contacts on a relay? I'm guessing no, but thinking it's something similar

Thanks so much for your help!

 

1.) What is the purpose of the capacitor?

2.) How many amps can this PICAXE micro controller handle?

3.) Are the C.1,C.2, C.3 etc. like dry contacts on a relay? I'm guessing no, but thinking it's something similar

Thanks so much for your help!

Capacitor C1 is for suppression of noise that might be on the power lead to the PICAXE; it's good practice to put a .1uF cap across the power leads of all integrated circuits.

Each I/O of the PICAXE can handle about 20mA directly; to control larger currents, it is necessary to add an additional component or two such as a power MOSFET.

Each of the I/Os are capable of outputting a logic high or low on command; these signals are used either directly (within the constraints mentioned above) or indirectly (as also mentioned above.) So, they are not dry contacts but they may be used in much the same way.

 

Capacitor C1 is for suppression of noise that might be on the power lead to the PICAXE; it's good practice to put a .1uF cap across the power leads of all integrated circuits.

Each I/O of the PICAXE can handle about 20mA directly; to control larger currents, it is necessary to add an additional component or two such as a power MOSFET.

Each of the I/Os are capable of outputting a logic high or low on command; these signals are used either directly (within the constraints mentioned above) or indirectly (as also mentioned above.) So, they are not dry contacts but they may be used in much the same way.

Thanks so much!