Fresnel lens?

A

AK

Guest
I am trying to maximize the amount of light that a red laser produces when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double the area.

I salvaged this from a laser printer and was wondering if that clear thing is a fresnel lens?

[img:32d30d7ed1]http://i64.tinypic.com/29w0bwi.jpg[/img:32d30d7ed1]


Am also trying to figure what that clear led is.?

There is a drawing on the circuit board that looks like this.

LD1
A |-->|C

Thanks.
 
On 6/8/19 12:48 AM, AK wrote:
I am trying to maximize the amount of light that a red laser produces
when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double
the area.

I salvaged this from a laser printer and was wondering if that clear
thing is a fresnel lens?

[img:f3e87054c2]http://i64.tinypic.com/29w0bwi.jpg[/img:f3e87054c2]

No, it's just an ordinary lens made from moulded plastic.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On 2019-06-08, AK <scientist77017@gmail.com> wrote:
I am trying to maximize the amount of light that a red laser produces when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double the area.

I salvaged this from a laser printer and was wondering if that clear thing is a fresnel lens?

[img:66afad9ef1]http://i64.tinypic.com/29w0bwi.jpg[/img:66afad9ef1]

certainly looks like a lens, if it has a ring structure it could be
fresnel, but such a small lens wouldn't need to use material saving
strategies like fresnel.

Am also trying to figure what that clear led is.?

There is a drawing on the circuit board that looks like this.

LD1
A |-->|C

Some sort of diode, probably an LED (possibly infrared), might be a photodiode

What is written next to other LEDs?


use multimeter diode test to check the voltage threshold.




--
When I tried casting out nines I made a hash of it.
 
On Saturday, June 8, 2019 at 2:31:18 PM UTC-5, Jasen Betts wrote:
On 2019-06-08, AK <scientist77017@gmail.com> wrote:
I am trying to maximize the amount of light that a red laser produces when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double the area.

I salvaged this from a laser printer and was wondering if that clear thing is a fresnel lens?

[img:61ee136d4c]http://i64.tinypic.com/29w0bwi.jpg[/img:61ee136d4c]

certainly looks like a lens, if it has a ring structure it could be
fresnel, but such a small lens wouldn't need to use material saving
strategies like fresnel.

Am also trying to figure what that clear led is.?

There is a drawing on the circuit board that looks like this.

LD1
A |-->|C


Some sort of diode, probably an LED (possibly infrared), might be a photodiode

What is written next to other LEDs?


use multimeter diode test to check the voltage threshold.



Thanks.


--
When I tried casting out nines I made a hash of it.

thanks Jasen.

1.43 v is the approx forward voltage drop.

Andy
 
On 6/8/2019 7:44 PM, AK wrote:
On Saturday, June 8, 2019 at 2:31:18 PM UTC-5, Jasen Betts wrote:
On 2019-06-08, AK <scientist77017@gmail.com> wrote:
I am trying to maximize the amount of light that a red laser produces when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double the area.

I salvaged this from a laser printer and was wondering if that clear thing is a fresnel lens?

[img:5043ca6da3]http://i64.tinypic.com/29w0bwi.jpg[/img:5043ca6da3]

certainly looks like a lens, if it has a ring structure it could be
fresnel, but such a small lens wouldn't need to use material saving
strategies like fresnel.

Am also trying to figure what that clear led is.?

There is a drawing on the circuit board that looks like this.

LD1
A |-->|C


Some sort of diode, probably an LED (possibly infrared), might be a photodiode

What is written next to other LEDs?


use multimeter diode test to check the voltage threshold.



Thanks.


--
When I tried casting out nines I made a hash of it.

thanks Jasen.

1.43 v is the approx forward voltage drop.

Andy
Did it light up? Try looking at it with your cellphone camera, it can
see light that your eyes can't.
Mikek
 
On Saturday, June 8, 2019 at 8:17:29 PM UTC-5, amdx wrote:
On 6/8/2019 7:44 PM, AK wrote:
On Saturday, June 8, 2019 at 2:31:18 PM UTC-5, Jasen Betts wrote:
On 2019-06-08, AK <scientist77017@gmail.com> wrote:
I am trying to maximize the amount of light that a red laser produces when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double the area.

I salvaged this from a laser printer and was wondering if that clear thing is a fresnel lens?

[img:f0cb08ccc6]http://i64.tinypic.com/29w0bwi.jpg[/img:f0cb08ccc6]

certainly looks like a lens, if it has a ring structure it could be
fresnel, but such a small lens wouldn't need to use material saving
strategies like fresnel.

Am also trying to figure what that clear led is.?

There is a drawing on the circuit board that looks like this.

LD1
A |-->|C


Some sort of diode, probably an LED (possibly infrared), might be a photodiode

What is written next to other LEDs?


use multimeter diode test to check the voltage threshold.



Thanks.


--
When I tried casting out nines I made a hash of it.

thanks Jasen.

1.43 v is the approx forward voltage drop.

Andy

Did it light up? Try looking at it with your cellphone camera, it can
see light that your eyes can't.
Mikek

It did not put out any visible light using just the diode test.

Cell phone did not pick up anything.

Andy
 
On Saturday, June 8, 2019 at 8:55:10 PM UTC-5, AK wrote:
On Saturday, June 8, 2019 at 8:17:29 PM UTC-5, amdx wrote:
On 6/8/2019 7:44 PM, AK wrote:
On Saturday, June 8, 2019 at 2:31:18 PM UTC-5, Jasen Betts wrote:
On 2019-06-08, AK <scientist77017@gmail.com> wrote:
I am trying to maximize the amount of light that a red laser produces when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double the area.

I salvaged this from a laser printer and was wondering if that clear thing is a fresnel lens?

[img:5293dabc2f]http://i64.tinypic.com/29w0bwi.jpg[/img:5293dabc2f]

certainly looks like a lens, if it has a ring structure it could be
fresnel, but such a small lens wouldn't need to use material saving
strategies like fresnel.

Am also trying to figure what that clear led is.?

There is a drawing on the circuit board that looks like this.

LD1
A |-->|C


Some sort of diode, probably an LED (possibly infrared), might be a photodiode

What is written next to other LEDs?


use multimeter diode test to check the voltage threshold.



Thanks.


--
When I tried casting out nines I made a hash of it.

thanks Jasen.

1.43 v is the approx forward voltage drop.

Andy

Did it light up? Try looking at it with your cellphone camera, it can
see light that your eyes can't.
Mikek

It did not put out any visible light using just the diode test.

Cell phone did not pick up anything.

Andy

Cell phone video shows a purple blinking light when I use my tv remote.(uses 2 AA batteries.)

The circuit that contains the "IR" led, has some 178 resistors and two 34 ohm resistors in series that go to the IR led.

Is it possible that the 1.74 volts going to it isn't enough voltage to light it?

Andy
 
On 2019-06-09, AK <scientist77017@gmail.com> wrote:
On Saturday, June 8, 2019 at 2:31:18 PM UTC-5, Jasen Betts wrote:
On 2019-06-08, AK <scientist77017@gmail.com> wrote:
I am trying to maximize the amount of light that a red laser produces when it hits a cadmium photo cell.

I went from a photocell with a small area to one with about double the area.

I salvaged this from a laser printer and was wondering if that clear thing is a fresnel lens?

[img:83aeb2c954]http://i64.tinypic.com/29w0bwi.jpg[/img:83aeb2c954]

certainly looks like a lens, if it has a ring structure it could be
fresnel, but such a small lens wouldn't need to use material saving
strategies like fresnel.

Am also trying to figure what that clear led is.?

There is a drawing on the circuit board that looks like this.

LD1
A |-->|C


Some sort of diode, probably an LED (possibly infrared), might be a photodiode

What is written next to other LEDs?


use multimeter diode test to check the voltage threshold.



Thanks.


--
When I tried casting out nines I made a hash of it.

thanks Jasen.

1.43 v is the approx forward voltage drop.

It's a LED, possibly infrared, photodiodes are usually lower voltage,
especially in consumer equipment.

it may still be possible to use it as a photodiode.

--
When I tried casting out nines I made a hash of it.
 

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