Will this circuit work when i hook up a battery

wayneh

Joined Sep 9, 2010
17,498
Is if your intention to hook your LED to a 9V battery using a 150 ohm resistor to limit the current?

I'm not sure about the switch pinout and is the orange thing just a wire? Other than those questions, it looks like it will work.
 

Thread Starter

polotwr

Joined Oct 26, 2016
12
Yes it is a 5.5-7.5 forward voltage LED
the resistor is 150ohm 1/8W
and a 9v battery

I redid it a little bit after realizing the LED was backward (new pic attached). but still not sure why it is not working
No light is being emitted

Sorry about the schematic looking like a child drew it, i drew one up in 30 seconds to attach as it may help
 

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dl324

Joined Mar 30, 2015
16,922
The resistor looks like 1/8W to me. It won't take that much current.

Edit: Are you sure about the forward voltage? White LEDs typically have the highest forward voltage and that's around 3.5V. My comment was assuming a forward voltage of around 2V.
 
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Thread Starter

polotwr

Joined Oct 26, 2016
12
I apologize it is 4.6V-6V forward voltage
and it is a 1/8W resistor

I attached the data from the manufacturer
it is a UV LED
 

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BR-549

Joined Sep 22, 2013
4,928
Try looking at a uv led with a smart phone or tablet camera. I read somewhere, where some cameras can see IR as a light and some can show UV as a light thru the camera.

It does work for IR....I've tried that. Testing tv remotes. Haven't tried UV.......but some say it works there too.
 

hp1729

Joined Nov 23, 2015
2,304
I need to hook up a 9v battery to power. will this work? never done this before. and i have no prior experience
From a 9 V battery? Not enough current, maybe.
(edited to add ... )
20 mA should work. Did you damage the LED when you hooked it up backwards?
 
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Thread Starter

polotwr

Joined Oct 26, 2016
12
so with a 9v battery
a 150ohm 1/8W resistor
this should work for the LED that needs 4.6-6V forward voltage and 20mA current?

if the components are correct then all I need is a way to test the function since I guess i won't be able to see any light

how would i verify the light being functional. is there a testing method or just a multimeter
 
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Thread Starter

polotwr

Joined Oct 26, 2016
12
even though it doesn't emit visible light?
the LED is not emitting any light whatsoever. if it was working I understand that UV light is invisible, but would it also emit visible light as well
 

Thread Starter

polotwr

Joined Oct 26, 2016
12
very good, so to put it simply.
Even if my light is working I will not be able to see any light coming from it when it is on unless I use one of those other methods?
I appreciate it, do you think the voltage and current are in line for what I am trying to accomplish.
9v battery to 150Ω 1/8W resistor to LED
LED calls for 20mA and has 4.6-6V Forward voltage typical and 7V max

I attached the currenta nd vltage data for my LED
as well as my schematic, please help me out with what im doing wrong
 

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wayneh

Joined Sep 9, 2010
17,498
I've never heard of a UV LED that doesn't emit visible light. I'm not saying there isn't such a thing, just that I'm unaware.

You really need to use something fluorescent to test it. Fluorescent dyes absorb UV wavelengths and re-emit light at a visible wavelength. Anything you have that glows in the dark will usually react strongly to UV light.

You should also be aware that UV light can damage - essentially, sunburn - your eyes without you knowing it until it becomes painful hours later. I wouldn't be too afraid of a single LED, but be careful.
 

Thread Starter

polotwr

Joined Oct 26, 2016
12
Yes, My contact at the manufacturer said that it will emit visible light as well

with that being the case, is my resitor to small? is the current from the 9v not enough? Im losing my mind as to why it is not firing up
 

djsfantasi

Joined Apr 11, 2010
9,163
Yes, My contact at the manufacturer said that it will emit visible light as well

with that being the case, is my resitor to small? is the current from the 9v not enough? Im losing my mind as to why it is not firing up
Have you checked the battery voltage? Your schematic should work, but you need a 1/4 W resistor. It may be a problem with the resistor. Can you take it out of the circuit and test that it is 150Ω?
 
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