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Week 4

Assignment

  • Create an electronic circuit that performs an action (at least blinking). Do not use a breadboard for connections.
  • Possible Variants:
    • Assemble (or even mill) a PCB for a simple blinking circuit.
    • Build a blinker using discrete components on a universal PCB or as a freeform circuit.
    • Create a blinker using an Arduino (we will cover this more next week; you can take inspiration from the Arduino Projects Book). Ensure the Arduino is placed in sockets so it can be removed.

The project

I have decided to use templated LED chaser with timer 555. This looked like a challenge for me (and it was) since I have very little experience with soldering.

Circuit diagram

Circuit diagram

Solder

Solder

Solder choice

I overestimated my abilities and thought I could do it easily at home, but it turned out to be a poor choice.

Starting with the hardest issue

I had little to no experience with soldering and I started with the main chip. Scan Offset

Then I got better with all the resistors and the second chip looked much better.

Finished with soldering

The final result turned out to be pretty ok at the first glance.

Final circuite

When I ran the first test of the LED chaser I supplied 12 V source and only one LED was turned on.

One light on

I still do not understand the behaviour. The current must have gone through the circuit, otherwise the LED light wouldn't have been on. Everytime I unplugged and plugged again the source, the next light turned on and the previous one turned off. When I was wiggling the source I got LED chaser for a brief moment. After a while the chip overheated and burnt.

Final countdown Burnt chip

Tips

  • When you have no or little experience with soldering, do it in the labs. And use smaller solder (experienced user would've done even with the bigger one)
  • Start with easier things (like resistors) and work yourself up to chips.
  • The solder burns finger even on very close proximity without actually touching the solder.