Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Why isn't this circuit working?

Status
Not open for further replies.

Benji966

New Member
Hello I am a very, very, very non-electronic person, so I thought I could do a simple task of making a LED circuit, but I guess I was wrong. I am running this off of a 13.8V source, theres 4 blue LEDS (3.2V ea), and I have a 1/8 watt 56 ohm resistor. By all accounts this should light up I suppose but it didn't, the LEDs all were working and I can assume the resistor was as well, but when I hooked it up, nada. I assume the problem lies with my soldering since I am no expert in that area. Any ideas on how to fix this would be great! Thanks!

Pics of my circuit:

**broken link removed**
**broken link removed**
 
By the looks of the second picture, absolutely everything is soldered together. That's got to be the biggest solder short I've ever seen.
 
hi benji.
Post the circuit diagram and a photo of the soldered side of the pcb.
 
Benji966 said:
Hello I am a very, very, very non-electronic person, so I thought I could do a simple task of making a LED circuit, but I guess I was wrong. I am running this off of a 13.8V source, theres 4 blue LEDS (3.2V ea), and I have a 1/8 watt 56 ohm resistor. By all accounts this should light up I suppose but it didn't, the LEDs all were working and I can assume the resistor was as well, but when I hooked it up, nada. I assume the problem lies with my soldering since I am no expert in that area. Any ideas on how to fix this would be great! Thanks!

I would assume you are running them in series at 20mA?

so the four LED's = 256mW!

and the resistor = 20mW!

So i would assume it would work!

make sure that the LED's are in series correctly, meaning that the +(anode) and - (cathode) are not touching together!
 

Attachments

  • LED.PNG
    LED.PNG
    1.6 KB · Views: 196
Last edited:
Yes, it looks like you've soldered all the connections together,
to make one join.

Other than that, the lamps are all the same way round,
and all the parts are in series,
its just that they need to be connected individually,
with a solder join for each junction.

Its not far off correct, just a bit of practice.

Oh, and dont have the copper conductor running along them in a line,
try to have a seperate bit of copper for each join.

Best of luck with it,
John :)
 
Ok so I resoldered everything, the blue lines are the solder, the L+ L- are the LED's. + and - are the source and ground. Still doesnt work. Did I do it wrong again?
**broken link removed**
 
Benji966 said:
Ok so I resoldered everything, the blue lines are the solder, the L+ L- are the LED's. + and - are the source and ground. Still doesnt work. Did I do it wrong again?
**broken link removed**
It is not easy to tell exactly what you meant by that picture, but it looks like you have two of the LEDs wired backwards.

Reverse the two LEDs, whose connections I've circled in yellow.
 

Attachments

  • ledtr3x.jpg
    ledtr3x.jpg
    143.6 KB · Views: 183
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top