Need help with infrared flashlight, please take a look

[protocol217]

i have been reading a bit about multimeter and i did this: i set my meter to this:
**broken link removed** and i put the com test lead to orange wire of the diode and VΩmA test lead to blue wire and i get reading on the screen 556
and when i switch the wires then i get no reading. i looked the diode with a ir sensitive camera in the dark room while doing the reading but there was no light coming out.
what should i do now?

 

[dr pepper]

Ok then.
Your meter has a position on the ohms ranges, 2000/(diode symbol), this is the position you want the range switch in for your diode test.
Put the black lead in the com, and the red in the V/(ohm)/mA socket.
Do your test, try the leads both ways on the device, one way the meter will show a 1 on the left hand side of the display or Ol to indicate an open, and the other way you will get a voltage reading, around 1.5 to 3v at a guess.
Put the range switch in the 200 ohm position to see if theres any infra red comming from the device, try the leads both ways.
Its very unlikely the meter will do any harm connected accross the device in the wrong polarity.
At a guess I'd say the tab side of the can is -

 

[dr pepper]

Just seen your last post, disregard the above, except for the same test on the 200 ohm range, on this range your meter will apply a little more current through the device and your more likely to 'see' something.
Try the same thing with a visible red led if you have one, to make sure your meter is lighting the device.
556 implies 0.556 volts which certainly implies the device is a detector not an emitter.

 

[protocol217]

i tried with green led diode and it lite up, so you are saying that this is an ir detector and it cannot be used like infrared flashlight, if so can you suggest me some good powerful ir diode to buy, i want to put it in the case i have.
and do you know for what was this device used for?

 

[dr pepper]

I cant be certain, its not reliable to type something by proxy but it does look that way yes, maybe it was used as part of a speed trap, or even just a system that could be positioned remotely and report that a vehicle has passed.

I got some of these recently, very cheap, you could probably fit these into your infra red system housing for a pro look:

**broken link removed**

I'd go for these anyways to be honest, they are probably a lot higher output than your 70's looking device, stuff as many as you can in the case on a bit of veroboard.

 

[protocol217]

I can fit like seven of them, what voltage is needed for 7 of them and do i need some resistors or something else for this or can i just connect them directly to a battery?
And what voltage battery do i need?
And how to connect them in parallel or in series?
and in my country a cant by 10 mm ir led, because there are nobody selling them, a can by a 5mm 850nm ir led, i think that is the same only 5 mm instead of 10 mm am i right.

 

[rumpfy]

I will clean up the sketch of the circuit digram and post it

 

[dr pepper]

Some sellers on ebay sell worldwide, and many include resistors.
Once we know the diode a resistor value can be calculated, I'd be inclined to have a resistor for each led, your battery voltage can be 4.5v upwards, depends what you have in mind, a 6v lead acid would give you long run hours, but if you ran the thing off the hotshoe you could get away with something a lot smaller.

 

[rumpfy]

Pls see the atached circuit diagram.

 

[protocol217]

I saw the diagram you drown, i am a beginner in electronics so i understand very little from this. but thank you for your efforts.
Do you suggest something new that i should try?

 

[rumpfy]

I'm going to suggest that I cant help much more. I dont have any feeling for the specifics of the device you have. Dr pepper seems to be a full bottle on this stuff and his posts #23 and 25 suggest he will be able to help you better than I. I'll continue watching the thread.

 

[protocol217]

OK, i will by some ir diodes and put them in this housing, i will post the results when i do that.

 

[rumpfy]

I read the web page of ICOP.
Seems they make IR type photographic stuff for surveillance. It could be that when the user wants to take an IR photo, the IR LED is then turned on and maybe this is done by grounding the grenn connection.
I have some questions for you to answer for yourself.

If the IR 'lamp' is working, are you able to detect light output from it? I have a IR detector I use for testing TV type remote controls. It's a thing I made up from bits in my shed. Can you get hold of say, the IR receiver used in TV's/VCR's/DVD's etc. Connect this up, and use the output to drive your multimeter. Then you will be able to test IR leds easily.

The circuit diagram references the various connection lugs. #705 and #706 is the connect points for the IR LED. The reason I say this is because in your photos in post 1, the black and orange wires seem to go to these points. can you check this?
#704 is the + supply connection, and I reckon #703 is the - supply connection; but I have no idea what #701 is used for. The suggestion is that #701 'should be' the connection to the IR LED anode.

My confusion is that I 'think' I got the connection of the IR LED correct, but did I?

Looking at the value of R715, I thought the resistance value was 270 ohm. The colours I got were red - purple - brown. Can you check this. I've lost the photos I had and they are now gone from this thread.

You should make an attempt to get the multimeter going so you can read current and voltage simultaneously.

 

[protocol217]

1. no i dont have an IR detector, i have a ir sensitive camera so that i can see if the diode is gloving infrared or not.
2. that is correct
3. there is no R715 the highest number is R714

i give up on this circuit and this diode or what ever it is.
i intent to bye a couple of these: https://uk.farnell.com/vishay-semiconductor/vsly5850/ir-emitter-850nm-5mm-pcb/dp/2300921
can you tell me if this is a good choice for night-vision binoculars generation 1, and i also intend to use it for my camera.
here is the pdf of the diode that i intend to buy: https://www.vishay.com/docs/83160/vsly5850.pdf
or if this is not a good choice please pick a ir led diode FROM THAT WEBSITE.

 

[protocol217]

Forget my previous post, i will order this one https://uk.farnell.com/osram/sfh4235/ir-emitter-850nm/dp/1827025
its powerful and it is good for ir flashlights.

Now, i ask how should i get it to glow, do i need a resistor or can i just connect it on 3 volts of dc, if i need a resistor which one ?
a simple diagram of how to connect this ir diode to the 3 v battery would be nice, that is all i need now, thanks.

 

[rumpfy]

If there is no R715, then what is the component at the side of the PCB which is hidden in the photo by the wires? Does it have colour bands?
From your comments it appears you are unable to check the LED you have?

First thing you need to do is to download the data sheet.
I got the data sheet from 'Element14', as they are known in OZ.
The LED is specified for pulse operation as well as DC.
For DC, the maximum forward current is 1 amp at a forward voltage of about typically 2.8 volt with amaximum of 3.4 volt.
It is specified for pulse operation and the actual permissible values of peak current and duty cycle are given in the Osram data sheet.
These things are priced at $11 AUD, and to use one you need to be careful not to destroy it with too much forward current.
I think now, after reading the data sheet, that the ICOP circuit board you have is a pulse generator for driving such an LED.
By using a pulsed driver arrangement, you will be able to get much higher values of IR light compared to operating the LED in the DC mode. So I believe you should attempt to get the icop circuit going. You can test this circuit board by using a couple of green leds in series as a load rather than the IR LED.
Can you get the transistor type numbers of the transistors on your icop board.

 

[dr pepper]

I read the datasheet too, it doesnt really specify a continous rating, ie not pulsed.
For a power rating of 3w though at a vf of 3v, a 3v supply isnt really high enough for a simple resistor type current limit, 4 'd' cells would give 4.8v if they are rechargeables, and to get 3w a resistor of 1.5 ohms would be needed, at 4.8v.
Be aware though this led might not be intended for continous operating, email osram technical and see what they say, I suspect you'll have to run it a bit lower wattage, a 3.3 ohm resitor would run the led at half power.
Also this led will need a heatsink,maybe a piece of ally in good thermal contact with the housing.
Safety: You may have noticed that a 3w white led is rather bright and can leave yellow dots in your vision, this led is the same but you cant see it which is worse, treat the led the same as you would a visible white one, point the led away from you all the time its powered, dont stare into it to see if you can see it lit, you wont but your retina's will, put a red visble led on the finished item to show its operating.

 

[protocol217]

here are some better pictures of ICOP board:
T704 - Ei BCY 57
T703 - Ei BCY 57
T702 - Ei BCY 71
T701 - Ei BCY 71

also i found this picture on internet maybe my devise was something similar to this:

 

[protocol217]

about the osram sfh 4235 led i read about led drivers:
https://power-topics.blogspot.com/2011/08/what-type-of-led-driver-or-power-supply.html
can i buy a driver that has output 3v and 1 A like this one: https://uk.farnell.com/on-semiconductor/cat4101tv-t75/driver-led-25vin-1a-5to263/dp/2102570

it is 1A but it is 3.5 v that can be lowered to 3 v with a resistor and wont effect the amperage am i right ? or that is not the solution, if not recommend me what should i buy to get that led glowing.
and thanks for the safety warning.

 

[protocol217]

Or can this one work: https://www.digikey.com/product-detail/en/RCD-24-1.00/PL/A/945-1639-5-ND/2766432
here is the datasheets: https://www.recom-power.com/pdf/Lightline/RCD-24PL.pdf

this version: RCD-24-1.00/PL/A has:
Current - Output (Max) - 1A
Voltage - Output 2 ~ 32 V

below the board it has 6 connections, 2 for the led ( pin 5 and pin 6 ) and it has for input voltage ( pin 1 and pin 4 ) ( 6 volts minimum )

the only thing i don't get is how to regulate the output voltage, it says Voltage - Output 2 ~ 32 V but i need 3 volts for my ir led.

so can this power supply ( driver ) work for my led ( OSRAM - SFH4235 ) ?