Soldering 101
From Fixme.ch
Intro to through-hole soldering
We will solder a blinking, customizable name tag. We will also discuss and explain the design and the theory of operation.
Circuit
- A discrete astable BJT multivibrator feeding into a 74HC595 shift register, which drives the LEDs directly.
- The shift register can serve up to 8 segments.
- The LED matrix can partitioned arbitrarily column-wise: multiple columns can be grouped onto a single counter output.
- each shift register output has one series current limiting resistor
- multiple display modes:
- blink (CLK goes into enable)
- fill slowly, clear slowly (last output inverted feeds back)
- fill slowly, clear at once (last output inverted goes to reset)
- rotate (last output feeds back)
- multivibrator speed can be adjusted with a pot
- on/off switch?
Components
- LED, $0.04650 @ 1000: http://search.digikey.com/us/en/products/WP710A10SRD%2FD/754-1593-ND/2769819
- 74HC595N,112, $0.378 @ 100: http://search.digikey.com/us/en/products/74HC595N,112/568-1484-5-ND/763088
- CR2032 holder, $0.4968 @ 100: http://search.digikey.com/us/en/products/3003/3003K-ND/227448
- PCB 5cm x 10cm, $1.498 @ 50: http://www.seeedstudio.com/depot/fusion-pcb-service-p-835.html
