Capacitor
A capacitor stores electric charge. In circuits it is used for smoothing, filtering, timing, coupling, and short-term energy storage.
Part images
What it is
A capacitor stores electric charge. In circuits it is used for smoothing, filtering, timing, coupling, and short-term energy storage.
How students use it
Students will see capacitors across power rails to smooth noise, near modules to steady power, and in timing or sensor circuits.
Pins and power
Ceramic capacitors are usually non-polarized. Electrolytic capacitors are polarized and must face the correct direction.
Passive part. Choose capacitance, voltage rating, and polarity/type for the circuit.
SunFounder notes the kit uses ceramic and electrolytic capacitors. Ceramic labels such as 103 and 104 encode picofarad values: 103 means 10 x 10^3 pF and 104 means 10 x 10^4 pF.
Voltage and safety
Use a voltage rating higher than the voltage in the circuit. Never reverse a polarized electrolytic capacitor.
Small kit capacitors are low-energy parts, but reversed electrolytic capacitors can heat, leak, or fail.
Datasheet notes
Generic capacitors are selected by capacitance, voltage rating, tolerance, dielectric/type, polarity, and package.
Common mistakes
Reading 104 as 104 pF instead of 100 nF, reversing electrolytic polarity, using too low a voltage rating, and expecting a capacitor to fix a wiring mistake.