A through hole resistor is a common electronic component used in circuits as a passive component to limit current or voltage. They are usually composed of a slender ceramic or plastic tube filled with a resistor made of conductive materials such as carbon or metal alloys. Both ends are soldered with metal leads, which can pass through holes on the circuit board and be fixed to the circuit board by welding.

Structural features:

Resistor: This is the core part of the resistor, which determines the resistance value of the resistor. It is usually made of materials such as carbon film, metal film, metal oxide film, or wire winding.

Lead wire: usually made of copper or tin plated copper material, used to connect resistors to the conductive path of a circuit board.

Shell: protects the resistor from external environmental influences and also has the function of heat dissipation. The shell material can be ceramic, plastic, or other insulation materials.

Color Ring: Many plug-in resistors have a series of color rings on their casing, which are used to represent the resistance value and accuracy of the resistor.

working principle:

When current passes through a resistor, the material of the resistor body has a certain blocking effect on the current, resulting in voltage drop and power loss. The greater the resistance value of a resistor, the stronger its resistance to current.

Usage scenario:

Plug in resistors are commonly used in early electronic devices and some applications that require high-power processing due to their ease of manual welding and maintenance. However, with the development of surface mount technology (SMT), many modern electronic products tend to use surface mount resistors (SMD resistors) that are smaller in size and more efficient in automated assembly.

Selection and application precautions:

Resistance value: Select the appropriate resistance value according to the circuit design requirements.

Power: Select the appropriate power level resistor based on the maximum power demand in the circuit.

Accuracy: Select the appropriate accuracy level based on the circuit's requirements for accuracy.

Temperature coefficient: Consider the stability of resistance at different temperatures and choose an appropriate temperature coefficient.

Package size: Choose the appropriate package size based on the circuit board space and installation method. The packaging of plug-in resistors usually takes the following forms:

1. Axial Led Resistor:

DO-35: This is a common axial package with a diameter of approximately 3.5mm and a length of approximately 12.7mm, suitable for medium power applications.

DO-41: slightly larger than DO-35, with a diameter of approximately 4.1mm and a length of approximately 14.6mm, suitable for higher power applications.

DO-201: With a diameter of approximately 2.0mm and a length of approximately 11.5mm, it is suitable for low-power applications.

2. Radial Led Resistor:

RAD-0201: With a diameter of approximately 1.0mm and a length of approximately 2.5mm, it is suitable for very small space requirements.

RAD-0301: With a diameter of approximately 1.5mm and a length of approximately 3.0mm, it is suitable for medium size space requirements.

RAD-0402: With a diameter of approximately 2.0mm and a length of approximately 4.0mm, it is suitable for larger space requirements.

3. Special packaging:

Metal film packaging: Using metal film as a resistance material, it has a lower temperature coefficient and higher frequency characteristics.

Thick film packaging: Using thick film printing technology, the cost is relatively low, but the accuracy and stability are relatively low.

Ceramic packaging: Using ceramic materials as substrates, suitable for harsh environments such as high temperature and high humidity.

Glass packaging: Using glass materials as substrates, it has extremely high stability and reliability.

When choosing the packaging of plug-in resistors, factors such as the installation method of the resistor, the layout of the circuit board, the working environment, and cost need to be considered. Axial packaging is suitable for mounting through holes, while radial packaging is suitable for surface mounting. Special packaging is selected based on specific application requirements. Ensure that the hole size on the circuit board matches the resistor pins to ensure good soldering quality.