First oscillator circuit (555 LED flashing) - Page 1
Forum section: electronics / projects

author: kalel
author_rank: Frequent Contributor
timestamp: June 08, 2017, 09:20:21 am
content: This is my first successful attempt at an oscillator circuit.I've taken a diagram from the internet (this one:http://www.555-timer-circuits.com/images/circuit-flashing-led-schematic.gif) and made only slight adjustments such as a different capacitor value (just what I had), a potentiometer which allows me to change the flashing frequency and duration from "slow and long" to "fast and short" and a dubious no color coding resistor instead of the designated 1k (should be nearly 1k).I also removed the resistor from the LED side, but instead have it on the power supply side (9v battery with resistors which I use to test LEDs).I had wires available, so I decided to go without attaching things to a board. It felt like it might be easier to do the resoldering that way if I get something wrong, which I did (I messed up the LED polarity somehow).It may look nasty (especially after some resoldering), but it works, so I'm happy.A few seconds flashing vid is here:https://streamable.com/ns71x

author: danadak
author_rank: Super Contributor
timestamp: June 08, 2017, 01:13:07 pm
content: Some useful construction techniqueshttps://1drv.ms/w/s!Al2JgiX7_qf0imH6fgNoCpiqDa3jRegards, Dana.

author: kalel
author_rank: Frequent Contributor
timestamp: June 08, 2017, 01:51:14 pm
content: Quote from: danadak on June 08, 2017, 01:13:07 pmArt!Edit: Do you know what was used for the 3rd image in your document? The metal wires need to be solderable and bendable.

author: Moondeck
author_rank: Regular Contributor
timestamp: June 08, 2017, 01:58:09 pm
content: Please, i beg you, get a breadboard

author: BradC
author_rank: Super Contributor
timestamp: June 08, 2017, 05:35:19 pm
content: Quote from: kalel on June 08, 2017, 01:51:14 pmThat looks like standard tinned copper wire.

author: kalel
author_rank: Frequent Contributor
timestamp: June 09, 2017, 06:11:02 am
content: Quote from: BradC on June 08, 2017, 05:35:19 pmThanks, I really like that style. Of course, PCB designs often look most professional as you can have pads exactly where you need them, but wires also work, no matter how bad or good (for talented people) you make them look!Of course, for more advanced projects and experienced people things like wire resistance and capacitive/inductive effects must be considered. To make an LED blink at some non-exact variable frequency, anything goes.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: June 09, 2017, 07:55:31 am
content: I do many projects like this:

author: kalel
author_rank: Frequent Contributor
timestamp: June 09, 2017, 08:05:19 am
content: Quote from: alsetalokin4017 on June 09, 2017, 07:55:31 amLovely! Are all of the wires solid core or?

author: alsetalokin4017
author_rank: Super Contributor
timestamp: June 09, 2017, 09:34:25 am
content: Yes, all solid, scavenged from 2-conductor telephone wire and 10-conductor ethernet wire.

author: kalel
author_rank: Frequent Contributor
timestamp: June 09, 2017, 01:16:09 pm
content: Quote from: alsetalokin4017 on June 09, 2017, 09:34:25 amI was looking at prices of solid copper wires, and they are not extremely cheap to say. 250 grams is about $10 here - not sure about purity but intended for electrical work. I'll check more and maybe find some better deals (or smaller sizes), but those are actually with a coating, which might be helpful to avoid accidental short circuits. The problem is if you need different thickness (and probably you do) you might end up with an expense of 30-50 USD if buying everything in 250 grams. Oh well, I guess this might be something unavoidable for such designs (and perhaps there are other cases in electronics where you might need it too).As funny trivia, I used telephone wires too (for connecting your telephone, 4 double-insulated wires, ready for making the cheapest, worst USB cable ever if you solder some connectors)... Chinese ones with only 3 strands of thin likely aluminum wire coated with copper (or maybe just painted and... who knows). Probably the worst wire to work with, but I tried to make a loop (360-900 degrees or at least 180 degrees whenever possible) to keep the solder joints stronger. I'm not sure if that's necessary, but seems like a decent thing to do whenever you can (I guess there's double advantage, both a stronger joint but also more surface area is connected so there should be less heat on the joint itself). That wasn't always possible because this wire is difficult to work with.