Capacitor Code to Value Calculator

Capacitor Code (3 Digits):

Tolerance (Optional):

Voltage (\( V \)) (Optional):

Capacitance:

µF

1. What is Capacitor Code to Value Calculator?

Definition: This calculator converts a 3-digit capacitor code into its capacitance value, determines the tolerance range if provided, and calculates the stored charge if a voltage is specified.

Purpose: It is used in electronics to decode capacitor markings, helping users select the appropriate capacitor for their circuits and understand its charge storage capacity.

2. How Does the Calculator Work?

The calculator uses the following rules and formulas:

Capacitance from Code:

\( \text{Capacitance (pF)} = (\text{First two digits}) \times 10^{\text{Third digit}} \)

Charge Calculation:

\( Q = C \times V \)

Where:

\( C \): Capacitance (F)
\( V \): Voltage across the capacitor (V)
\( Q \): Charge stored (C)

Tolerance Range: If a tolerance letter is provided (e.g., K for ±10%), the range is calculated as:

Lower limit: \( C \times (1 - \text{tolerance percentage}) \)
Upper limit: \( C \times (1 + \text{tolerance percentage}) \)

For asymmetric tolerances like Z (+80%, -20%), the range is adjusted accordingly.

Steps:

Enter the 3-digit capacitor code.
Optionally select a tolerance letter (J, K, M, Z).
Optionally enter the voltage across the capacitor with its unit (V, mV, kV).
The calculator computes the capacitance in pF, converts it to nF, µF, mF, and F, and displays all values.
If tolerance is provided, it calculates the capacitance range.
If voltage is provided, it calculates the stored charge using \( Q = C \times V \).
Results are displayed with 4 decimal places.

3. Importance of Capacitor Code to Value Calculation

Calculating the capacitance from the code is crucial for:

Circuit Design: Ensuring the correct capacitor is used in a circuit based on its capacitance and tolerance.
Component Selection: Understanding the range of possible capacitance values to account for manufacturing variations.
Charge Storage: Determining how much charge a capacitor can store at a given voltage, which is essential for power supply and timing circuits.

4. Using the Calculator

Example: A capacitor has the code "104K" and is connected to a 10 V source:

Capacitor Code: 104
First two digits: 10
Third digit (multiplier): 4
Capacitance: \( 10 \times 10^4 = 100,000 \, \text{pF} = 100 \, \text{nF} = 0.1 \, \text{µF} \)
Tolerance (K): ±10%
Range: \( 90,000 \, \text{pF} \) to \( 110,000 \, \text{pF} \) (90 nF to 110 nF)
Voltage: 10 V
Charge (\( Q \)): \( C \times V = (0.1 \times 10^{-6} \, \text{F}) \times 10 \, \text{V} = 1 \times 10^{-6} \, \text{C} = 1 \, \text{µC} \)
Result: Capacitance = 100,000 pF (100 nF, 0.1 µF), Range = 90,000 pF to 110,000 pF, Charge = 1 µC

5. Frequently Asked Questions (FAQ)

Q: What does the 3-digit capacitor code mean?
A: The first two digits represent the capacitance in pF, and the third digit is a multiplier (power of 10). For example, "104" means \( 10 \times 10^4 = 100,000 \, \text{pF} \).

Q: How does tolerance affect the capacitance value?
A: The tolerance indicates the range of possible capacitance values due to manufacturing variations. For example, a 100 nF capacitor with a K (±10%) tolerance can range from 90 nF to 110 nF.

Q: Why calculate the charge stored in a capacitor?
A: Knowing the charge helps in designing circuits where capacitors store energy, such as in timing circuits, filters, or power supplies, ensuring they meet the required energy storage needs.