Master the Basics: Understanding Capacitors in Parallel
When multiple capacitors are placed in parallel, their total capacitance is simply the sum of their individual capacitances. This makes it easy to create new capacitance values using the capacitors available in your parts kit.
Why Capacitance Adds in Parallel
Each capacitor consists of two conductive plates separated by a dielectric. When capacitors are connected in parallel:
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The top plates are at the same voltage as each other.
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The bottom plates are also at the same voltage.
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This effectively increases the total plate area, allowing more charge storage and increasing capacitance.
Example: To create a 12µF capacitor, you can combine:
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One 10µF capacitor
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Two 1µF capacitors
Since capacitances add in parallel, the total capacitance will be:
C_total = C₁ + C₂ + C₃ = 10µF + 1µF + 1µF = 12µF
Voltage Rating in Parallel Capacitors
While capacitance adds, voltage rating does not. The maximum voltage a parallel capacitor network can handle is limited by the lowest-rated capacitor in the group.
Example: If you combine:
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A 10µF capacitor rated at 25V
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Two 1µF capacitors rated at 50V
The overall voltage rating remains 25V because exceeding this would damage the 10µF capacitor.
Tolerance in Parallel Capacitors
Capacitors have a tolerance rating, indicating how much their actual capacitance may vary from the stated value. When capacitors with the same tolerance are combined in parallel, the overall capacitance will also have that same tolerance.
Example: If all capacitors have a ±5% tolerance, the total capacitance will also have a ±5% tolerance.
Takeways
Combining capacitors in parallel is a simple and effective way to achieve desired capacitance values while maintaining the same voltage across all components. However, always ensure that the voltage rating of the capacitors is suitable for your circuit. Understanding these principles will help you make better decisions when designing and optimizing your electronic projects!
