This is beautiful, and I like it a lot, but I was slightly disappointed to find that they do not function by increasing the voltage as the day goes on. But then I remembered that that's how pins work. It IS measuring voltage!
This is beautiful, and I like it a lot, but I was slightly disappointed to find that they do not function by increasing the voltage as the day goes on. But then I remembered that that's how pins work. It IS measuring voltage!
Transistors are much more efficient full on or full off. So for the most part for transistor based voltage control they pulse the transistors with a duty cycle equivalent to the voltage needed and integrate it with capacitors, keep the pulse on 25% of the time you have 25% of the voltage sort of thing. Thus the acronym PWM (Pulse Width Modulation)
Note that transistors can be controlled to directly regulate the voltage. This will draw much more power than pulsing them.
It is also kind of neat how voltage is measured. Probably day one stuff in EE school but I thought it was interesting. Meters like the one in the article are sort of obvious. pull a spring with an electromagnet and see how far it gets. but how is voltage read electronically. The answer is capacitors. you time how fast a capacitor charges.