Recently, the microcontroller enthusiast has been using Phyphox and ESP32 Bluetooth to redraw the I-V characteristics of a light bulb, continuously changing the experimental parameters in hopes of finding the optimal settings.
In one experiment, the enthusiast set the sampling frequency of the ESP32 to 100Hz and slowly adjusted the voltage across the light bulb from zero to 1.5 volts, obtaining the expected I-V characteristic curve of the light bulb. This curve had a denser data point distribution and stronger regularity compared to previous attempts.
The enthusiast subconsciously reduced the power supply voltage and found that the I-V characteristic curve obtained was inconsistent with the one drawn during the voltage increase process.
It seemed that the enthusiast realized something and quickly conducted multiple control experiments, slowly increasing, rapidly increasing, slowly decreasing, and rapidly decreasing the power supply voltage. It was confirmed that the I-V characteristic curves were indeed different; the speed of voltage increase or decrease affected the resulting curves.
If the power supply voltage increases rapidly, a strange phenomenon occurs where the slope first decreases and then increases, indicating that the resistance of the light bulb increases with voltage initially and then decreases, which is quite peculiar.
What causes this bizarre change in the light bulb’s I-V characteristic curve? How can we explain this strange variation?
This requires further in-depth research!
| Maker Jiaozuo |
Henan Maker Jiaozuo is the WeChat public platform of the Jiaozuo City Maker Education Master Studio, focusing on maker education, sharing maker cases, explaining innovative methods, inspiring creative design, conducting scientific inquiries, organizing social investigations, guiding thesis writing, participating in maker competitions and patent applications, and discovering, nurturing, and achieving a group of students with innovative potential.
Henan Public Number: chuangkejiaozuo
Henan Master Blog: http://blog.sina.com.cn/updays
Long press to recognize, follow, and share
– END –
