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What resistor value do I need?
We’ll use the following formula to determine the resistor value: Resistor = (Battery Voltage – LED voltage) / desired LED current. For a typical white LED that requires 10mA, powered by 12V the values are: (12-3.4)/. 010=860 ohms. To use several LEDs in parallel, sum the current values.
Why do we use resistor values?
The standardization of resistor values serves several important purposes. When manufacturers produce resistors with different resistance values, these end up approximately equally spaced on a logarithmic scale. This helps the supplier to limit the number of different values that have to be produced or kept in stock.
Do you add resistors in parallel?
Answers: As more and more resistors are added in parallel to a circuit, the equivalent resistance of the circuit decreases and the total current of the circuit increases. Adding more resistors in parallel is equivalent to providing more branches through which charge can flow.
How do you find the resistor value of a resistor?
To determine values other than the base, multiply the base value by 1, 10, 100, 1k, or 10k. Standard resistor values are calculated using the simple formula given below. Round the results to the proper number of significant figures (three for 1% and 2%, two for 5% and 10%).
How to calculate the tolerance of a resistor?
This calculator will help you identify the value, tolerance and temperature coefficient of a color coded resistor by simply selecting the bands colors. It will also calculate the minimum and maximum values based on the tolerance ratio. This calculator supports resistors with 3, 4, 5, and 6 bands. How to use?
What does the color code on a resistor mean?
The resistor color code shown in the table below involves various colors that represent significant figures, multiplier, tolerance, reliability, and temperature coefficient. Which of these the color refers to is dependent on the position of the color band on the resistor.
How are the bands on a resistor read?
Reading Color Codes Resistors cases usually have three to six bands that indicate their resistance, tolerance and sometimes their temperature coefficient of resistance (TCR). The bands are read from left to right. The reading direction is not always clear.