Hi Everyone,

This is my first post, so firstly..

Hello!, My name is James, I'm from Birmingham, England. I'm a qualified domestic electrician but know very very little regarding circuitry type electrics.

I have been trying for about a week now to create a simple astable / square type timer circuit to control an LED.

I am getting no results from a 555 timer, I have tried swapping timers, resisiters, capacitors. I am getting no results.

The only thing I can see that might differ to any of the tutorials is the supply. I am using a 9v DC battery, but no tutorial I have read, as really specified the input.

I'm sorry everyone for being a bit of a noob here, can anybody help? As I'm seriously ready to throw in the towel!!

Thanks again!!
James

 

Can you post some sort of drawing/schematic of what
you have tried?

Tell us exactly (part numbers and/or values) the parts
you have.

Explain in detail, the best you can, of what is happening
or not happening.

I'm sure we can figure this out.

 

Hi Pencil,

http://www.555-timer-circuits.com/up-down-fading-led.html

The first tutorial I tried was the link above, as far as I'm aware all the components are the same, the only difference being that the cap I used was 25v not 16v?

I will get more information of the components I have used.

Thanks again for your reply!

 

Maybe this will help.

 

I have a different set of tutorials that is based off this site. They are actually part of the AAC eBook.

The 555 Projects

What are you specifically trying to do?

This is probably the simplest circuit out there to flash an LED.

555 Hysteretic Oscillator

 

This may be a stupid question but the resistor I am using are blue, and 1/2w could this be what it causing the problem?

Thanks for the tips so far!

 

Just to make sure you weren't given a bad
example I threw that circuit on a solderless
breadboard. I does work as shown. The only
differences I had was I used a 2N4401 transistor
and used a 30K resistor (instead of a 33K), because
that was what I had at arms length.

Here are some suggestions for you to check:

1. Identify pin numbers of the 555 (look for reference notch or dot).
2. Identify pins of transistor (emitter, base, collector).
3. Identify + and - of capacitor correctly.
4. Identify anode (+) and cathode (-) of LED correctly.
5. Check all connections before applying power.

 

This may be a stupid question but the resistor I am using are blue, and 1/2w could this be what it causing the problem?

Not if it is the correct value (33KΩ or 470Ω).

 

I have checked all of the above over and over and still no joy, I have tried switching polarity on all components, I have swapped components, I have starting from scratch about 6 times. I literally have no ideas.

Thanks for your help guys, I think I'm gonna have to throw in the towel, I really don't get it.

Thanks again!

 

Have you tried my circuit? It has a complete drawing of how to wire it.

 

Don't give up.

I'm sure it it something simple.

Tell us what transistor you are using, we can check
pinout of that first, it is not uncommon to misunderstand
the locations of the pins.

 

Post a closeup photo of your breadboard. If it's a wiring problem, someone will spot it.

 

Maybe a dead battery? Try connecting just the battery, LED, and 470 resistor in series. If it lights, then at least those three components are good.