The role of resistors in circuits

The role of resistorsin circuits

Chip resistors are also business card type fixed resistors, which are one of the metal glass glaze resistors. It is a resistor made by mixing metal powder and glass glaze powder and printing it on the substrate by screen printing. It is resistant to humidity and high temperature, and has a small temperature coefficient. It can greatly save the cost of circuit space and make the design more refined. Let me take you to understand its role in the circuit.

Partial pressure

When the current flows through the resistor, a voltage drop is generated in the circuit. If the voltage drop is shared in the series circuit, the voltage at the other end is smaller. The following are more typical applications.

The fixed value resistor and the variable resistor NTC are connected in series. When the temperature changes, the resistance of the NTC changes and the voltage across R1 changes to calculate the temperature value.

Limiting

Resistor hinders the current. The larger the resistance in the loop, the smaller the current that flows. Generally, resistors are used to limit current to protect components. The following are typical applications. The current flowing through the LED should not be too large, otherwise it is easy to burn the LED, so add a resistor to limit the current.

The five major functions of resistance in electronic circuits

Pull up/down

In the initial state of the circuit, an uncertain level may be encountered. In order to prevent the circuit from malfunctioning due to the uncertain level, a resistor must be used to pull up to the power supply or pull down to the ground to stabilize the initial level. In the initialization stage, in order to prevent the uncertainty of the pin level of the microcontroller from causing a malfunction to the circuit, a pull-up/pull-down resistor is added to enhance the stability of the circuit.

Jumper

To facilitate debugging when debugging a circuit, a resistor is generally used as a jumper to switch between different functions, which is similar to a switch to facilitate circuit debugging.

Filter

In circuits where digital circuits and analog circuits are mixed, if the signal frequency is not high, single-point grounding is generally used, and each grounding point is connected to the power ground through a resistor, which can play a role in filtering and anti-interference.

load

In high-power circuits, power resistors may be used as loads, such as cement resistors. This type of resistor has a small resistance value, but is large in size and good for heat dissipation. It can be used as a load in the circuit.