LED Power Problem

$ausage$

Hi,

I have a set of hoepfully 8 LED's I need to wire up. The guy in Maplins gave me a deep blue resistor but I think it will be too strong. the link for the LED's is _http://www.maplin.co.uk/module.aspx?moduleno=2047 I have dry wired up some and it lights the first one but nor more off a 9V battery.

Where am i going wrong? I want them all to be the same.

Here all day to reply.

Thanks

1Love

witnessmenow

How do you have the circuit set up? Are the LEDS in series or parrallel?

Also does the resistor have bands of colours on it? If so what are the colours?

$ausage$

started paralel but it worked as in in serial so tried serial and same thing such a bad drop off before even the second led with or with our resistor

witnessmenow

are you soldering them or using a bread board to connect them up?

$ausage$

Tried bread board but couldnt get it working tried soldering but same problem then the solder would not stick to pcb so tried just using wire and twisting connections

Dublin_Gunner

$ausage$ wrote: »

Hi,

I have a set of hoepfully 8 LED's I need to wire up. The guy in Maplins gave me a deep blue resistor but I think it will be too strong. the link for the LED's is _http://www.maplin.co.uk/module.aspx?moduleno=2047 I have dry wired up some and it lights the first one but nor more off a 9V battery.

Where am i going wrong? I want them all to be the same.

Here all day to reply.

Thanks

1Love

Sounds like you have the circuit completed across the first LED.

Do you have a schematic of the design you're trying to create?

Here's some good, simple info on wiring
http://wolfstone.halloweenhost.com/Lighting/litlpo_PoweringLEDs.html

and here's a little calculator for powering the circuit, based off number of LEDs, and their typical forward Voltage and current specs
http://led.linear1.org/led.wiz

It will even output a schematic, or wiring diagram for you

But yes, a solderless breadboard is indispensable for creating mock up circuits. I got a very good one for about €20 in Maplins.

$ausage$

how does the bread board work ie which bits are connected under the slots? thats my problem where to put power etc

Dublin_Gunner

In a breadboard, you usually have power rails, above and below the component area.


Power

---

Power

---

Comp||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Comp||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Comp||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Comp||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Power

---

Power

---

Connected like so. The power rails are connected horizontally, and component section vertically. Some breadboards may have disconnected sections, but in general, this is how you would work it.

Generally, you woul use the top power rails for +V, and the lower ones for -V and gnd.

You connect power to the main circuit by using small pieces of wire to bridge from the power rail to the component section.


Its sounds as though you have very little experience with electrical / electronic design, so maybe a little reading would help you in this, and future projects?

This should be marginally better than my attempt at a drawing of a breadboard!
http://en.wikipedia.org/wiki/Breadboard

$ausage$

No i did it for Alevel like but thats a few years now!!! thsi is my one and only project! thank god!

Dublin_Gunner

$ausage$ wrote: »

No i did it for Alevel like but thats a few years now!!! thsi is my one and only project! thank god!

Apologies so, I didn't mean to sound patronising!!

Hope the info I posted helps

$ausage$

oh no you wernt!!!!

yeh it has helped! I am going to try it in the next hour or so. Really want to get this done wreaking my life

GF's who woudl have em! :P

$ausage$

IMAGE_052.jpg
IMAGE_053.jpg

not working

any advice?

Dublin_Gunner

lol


You don't have your jumper leads connected to the power rails. They run horizontally, not vertically. Connect the jumper leads to the same 'row' beside where you have the battery terminals plugged in.

Oh, and ensure you have the LED the correct way around.

$ausage$

changed the rails but still now joy hummmmmm

Dublin_Gunner

1. Have you checked the polarity of the LED?
2. Tested that the LED actually works?
3. Checked with a multimeter that you're actually getting power to the circuit?

Ensure your wires and the legs of any components are actually touching the metal inside the holes on the breadboard.

$ausage$

1 yes
2 yes
3 dont have one

i have built the circit on top of the bread board loose and it works.

must be my jumping does it mattehr wher on the vert you place components?

$ausage$

ahh got the bb working was wrong way round

DublinDilbert

your problem is how you wired up your bread board....

On the main area all the rows are connected, but not the columns, ie:-
1A 1B 1C 1D 1E are all connected
2A 2B 2C 2D 2E are all connected
3A 3B 3C 3D 3E are all connected
...
28A 28B 28C 28D 28E are all connected


Hence 2A is Not connected to 3A


Your power rails are also connected wrong...

If you could get a cheap multimeter and learn how to test for continuity between various components, you'd be sorted...

$ausage$

where is best place to get white leds may be next day del?

backboiler

Looks like all lines (including power rails) run the same direction on that breadboard. Vertical as you took the picture, horizontal if you're reading the numbers and letters. But it looks like you've figured that much out by now.

That looks like a 10-ohm resistor (brown-black-black), which isn't suitable for a 9 V supply to a single 2-odd Vf diode.

See post number 8 and on in the following thread for more information.
http://www.boards.ie/vbulletin/showthread.php?t=2055533270

$ausage$

god dam maplin idiots! plus they game me the wrong green leds im just after finding. GRRRRR

I need 12 leds in parellel what do i need to get can you fill me in? the brighter the better what resistor leds etc. I have a toggle switch just not on board at min

backboiler

1. Explain why you need them in parallel.
2. What's wrong about the LEDs?

$ausage$

I need them not to dimm over the span so parallel correct?

They must have a hight usage as they light up put you would hardly notice, I have two set orange and green all oragne work green dont.

Thanks

backboiler

Not trying to be smart here. It's very hard to understand what you're trying to say. I'll have a guess anyway but next time take an extra minute, fix the spelling mistakes and see if the sentence makes sense before you press "Submit Reply".

The thing is that if you have each LED in parallel the current use goes up and so if you're powering off a battery it'll not last as long. Take an example, if you use that PP3 battery in your pictures to power your 12 LEDs in parallel, each drawing 20 mA for a total of 240 mA. That particular battery's capacity is 550 mAh so you'll be looking at it lasting just over 2 hours. Is that enough for you? You can treble this if you follow the instructions in the link I sent a few posts back. All the calculations are there along with pictures.

As for bright LED suppliers, try ebay. You'll be looking at a week or two delivery time from Hong Kong. I've bought from a place called jeled-hk, typically coming in around €10 for 50 LEDs, plenty bright enough to blind a fella.