Matchbox LED Oscilloscope
author: autotelic
2 layer board of 1.40 x 1.90 inches (35.6 x 48.3 mm)
Uploaded:
April 05, 2019
Shared:
April 05, 2019
Total Price:
$13.30
This is one of my favorite Forrest M. Mims, III designs from when I was a kid. The venerable LM3914 (meant for digital LED meter applications) and 2 other CMOS ICs drive a TIL305 5x7 LED dot matrix display to make a very simple toy oscilloscope. Even with the low resolution, one can clearly see waveforms like sine, triangle, and square waves. The sweep oscillator is 2 NAND gates wired in a loop with an RC network in the middle. Max frequency with the 100K pot and 0.1uF oscillator is around 1KHz.
This is one of my favorite Forrest M. Mims, III designs from when I was a kid. The venerable LM3914 (meant for digital LED meter applications) and 2 other CMOS ICs drive a TIL305 5x7 LED dot matrix display to make a very simple toy oscilloscope. Even with the low resolution, one can clearly see waveforms like sine, triangle, and square waves. The sweep oscillator is 2 NAND gates wired in a loop with an RC network in the middle. Max frequency with the 100K pot and 0.1uF oscillator is around 1KHz.
