1. Basic principles for resistor selection
In the early stages of circuit design, selecting appropriate resistors is the basis for ensuring circuit performance and reliability. The following three principles are critical in guiding the resistor selection process:
Certification and standards: Give priority to manufacturers that have been audited and certified by authoritative certification bodies and whose production lines can produce resistors that meet high-level standards. This principle guarantees the basic quality and performance standards of resistors and provides a solid foundation for the stable operation of electronic products.
Comprehensive performance considerations: Among the many manufacturers, emphasis should be placed on those resistors that offer the advantages of performance, quality, efficiency, cost-effectiveness and superior service. These manufacturers can often provide more comprehensive technical support and after-sales services, thereby effectively reducing overall operating costs and improving product competitiveness.
Direct procurement: Based on the model catalog, ordering resistors directly from manufacturers that meet the above requirements can ensure that the purchased resistors meet the design requirements and reduce the quality risks that may be introduced by intermediate links.
2. Key considerations when selecting resistors
1. Voltage and current limits:
Resistor selection must consider its voltage and current limitations. Resistors may undergo breakdown after exceeding a certain voltage, which may cause their resistance to increase irreversibly or completely fail. The occurrence of breakdown depends on many factors, including the distance and shape between lead wires, and the voltage withstand performance of the insulating material between slots. For this reason, the voltage applied to the resistor should be strictly controlled during design to avoid exceeding its safe operating range. In addition, the resistor's rated power dissipation and nominal resistance jointly determine its rated current. Designers need to use this parameter to ensure that the resistor operates within a safe current range to avoid performance degradation or failure due to overheating.
2. Load power and temperature control:
The resistor converts electrical energy into heat energy when working. This process will not only cause the temperature of the resistor itself to rise, but may also affect the working environment of surrounding components. Changes in resistor performance are partly reversible, as described by the temperature coefficient, and partly irreversible, as due to aging phenomena. Therefore, the stability and reliability of a resistor largely depend on its thermal stability under long-term operating conditions. The load power of the resistor must be considered during design to ensure that it operates stably within the allowable heating temperature range, thereby ensuring the long-term stability and reliability of the circuit.
Through the above analysis, we know that the selection of resistors not only needs to consider their basic electrical performance, but also needs to comprehensively consider many factors such as the manufacturer's certification standards, product quality and service. When designing electronic circuits, proper selection and application of resistors is key to ensuring the performance and reliability of electronic equipment.