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Fresnel lens?

Started by AK June 8, 2019
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]http://i64.tinypic.com/29w0bwi.jpg[/IMG]


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]http://i64.tinypic.com/29w0bwi.jpg[/IMG]
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]http://i64.tinypic.com/29w0bwi.jpg[/IMG]
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.
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]http://i64.tinypic.com/29w0bwi.jpg[/IMG] > > 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]http://i64.tinypic.com/29w0bwi.jpg[/IMG] >> >> 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]http://i64.tinypic.com/29w0bwi.jpg[/IMG] > >> > >> 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]http://i64.tinypic.com/29w0bwi.jpg[/IMG] > > >> > > >> 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]http://i64.tinypic.com/29w0bwi.jpg[/IMG] >> >> 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.