The Impact of Working Duty on A DC Solenoid Temperature Rise: Understanding the Relationship
Part 1 : what is the Working Duty of a DC solenoid and Its Impact on Temperature
1.1 Working duty refers to the ratio of the on - time to the total cycle time of an electromagnetic device. For example, a solenoid with a 50% working duty means it is on for half of the total time cycle. The working duty cycle directly affects the amount of heat generated by the solenoid.
1.2 Heat Generation and Working Duty
According to the Joule's law , where is the heat generated, is the current, is the resistance and is the time. When the working duty is high, the solenoid is on for a longer time during a cycle, and more heating is generated. This accumulated heat can cause the temperature of the solenoid to rise.
1.3 Effect of Temperature Resistance on Working Duty
As the temperature of the solenoid rises due to heat generation, the resistance of the solenoid coil usually increases. For most conducting materials, such as copper, the resistance - temperature relationship is approximately linear over a certain temperature range. This increase in resistance can lead to a decrease in current according to Ohm's law , where is the voltage.
1.4 Impact on Magnetic Field and Working Duty
The magnetic field strength of a solenoid is related to the current flowing through the coil and the magnetic permeability of the core material. When the resistance increases and the current decreases due to temperature rise, the magnetic field strength also decreases. In some applications, a certain minimum magnetic field strength is required for the solenoid to function properly. Therefore, as the temperature rises and the magnetic field weakens, the working duty may need to be adjusted to ensure that the solenoid can still meet the performance requirements. For example, if the solenoid is used in a solenoid valve control application, a weakened magnetic field may not be able to open or close the DC solenoid valve completely. In this case, either the working duty needs to be reduced to prevent the overheating and further performance degradation, or better temperature - resistant materials need to be applied to maintain the original working duty.
Part 2 : Interdependence and Considerations in Design
2.1 Material Selection Based on Working Duty and Temperature Resistance
When designing a solenoid for a specific application with a given working duty, the temperature resistance of the materials used for the solenoid coil and the core must be considered. For applications with a high working duty (e.g., continuous operation), materials with better temperature resistance, such as high - temperature - resistant insulating materials and core materials with a high Curie temperature, should be selected to prevent overheating and performance degradation.
2.2 Cooling System and Working Duty Adjustment
In addition to material selection, an effective cooling system can also affect the relationship between temperature resistance and working duty. If a good cooling system is in place, such as forced - air cooling or liquid - cooling, the solenoid can operate at a higher working duty without overheating. Conversely, without proper cooling, the working duty may need to be limited to keep the temperature within the acceptable range of the solenoid's temperature resistance.
Part 3 Summery :
As we all know, once the push-pull electromagnet is energized, it will generate force. Under the same power consumption, the force generated by different distances of travel is also different. Under the same travel conditions, such as different power consumption, the force of the solenoid push-pull electromagnet will also be different, because different power consumption corresponds to different power-on rates (that is, duty cycle). There is a rule for reference as follows: 1. The larger the travel, the smaller the force; 2. The higher the power consumption, the smaller the force. Find the best stable working mode: The force/stroke curve that the push-pull electromagnet may generate just meets the force and stroke curve required by the application product equipment.
When the solenoid push-pull electromagnet is used, the safety function must be considered, that is, the test of the force should be the force measured after the temperature rise of the push-pull electromagnet is stable at a certain power-on rate. In some cases, the initial force is about 1.5 times the force after the temperature rise is stable. If the power-on rate of the product is very low (only a few times a day, and the time is very short), the safety factor can be reduced to 1.2 times.
DC push-pull solenoid may cause instability and overheating during operation. Our professional experience engineers will formulate relevant specifications and standards according to the actual application of customers, and make samples for test and application. Different products and different cases require different specifications and the standards. For example, after the temperature rise of individual push-pull solenoid stabilizes after 2 hours of continuous working, the temperature of the push-pull solenoid housing temperature is not allowed exceeding 80 degrees. Dr. Solenoid has always offered high strictly controls quality, and professionally services for our global customers. With more than eighteen years experience in making DC Solenoid and Solenoid valve actuator, our products range covers the bistable rotary solenoid, frame type push-pull solenoid, starter solenoids, electromagnetic clutch, electromagnetic solenoid door lock, suction cup electromagnets, and tubular push-pull solenoids with high-quality and professional customization services for different industries such as printing, high-speed rail, rail transit, electrical automation, finance, electronic equipment, and amusement machines. If you have any needs for related electromagnet products, please contact us.