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Andrew Kesterson
2026-06-04 18:56:38 -04:00
parent 263aa54a09
commit 25aa9be199
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05-photoresistors/README.md
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@@ -44,7 +44,7 @@ Okay, hear me out. Consider this circuit, wired up on a breadboard:
+5V --> 10k Resistor --> Wire --> GND
```
Our intuitio here says that, on a 5v current, a 10k resistor should give us an output of about 2.5v, right? Right, let's go with that.
Our intuition here might say that, on a 5v current, a 10k resistor should give us an output of about 2.5v, right? Right, it's not a perfect assumption, but let's go with that.
* Put your voltmeter red probe on the +5V rail side of the resistor, and the black probe on GND. You will see 5v.
* Put your voltmeter red probe on the downstream side of the resistor, away from the +5V rail. Put your black probe on GND. What do you think you will see? 2.5v? No. You will see 0v.
@@ -78,5 +78,5 @@ The voltage reading of any given voltage divider is going to be equal to the inp
$$ Vout = 5 * \frac{10k}{10k + 10k} $$
... Or `Vout = 2.5v`. For fun, stick different value resistors in the R1 and R2 place. Probe it, and see how the value at the tap changes.
... Or `Vout = 2.5v`. For fun, stick different value resistors in the R1 and R2 place. Probe it, and see how the value at the tap changes. And THAT is why potentiometers act like a voltage divider - because by turning the dial, you can change the sweep of the wiper, which changes the size of the resistive material on both sides of the wiper, which changes the resistance value of the material on both sides of the wiper, changing the resistance values of the two sides of the potentiometer!