What is the difference between a small electronic radiator and a large electronic radiator?

Time:2023/12/6 15:56:22

Any device has a certain loss when working, and most of the loss becomes heat. Low-power devices have small losses and do not require heat sinks. And high-power devices loss, if you do not take thermal measures, the core temperature can reach or exceed the allowable junction temperature, the device will be damaged. Therefore, it must be added to the heat sink, the most commonly used is the power device mounted on the radiator, the use of heat sinks will be scattered to the surrounding space, if necessary, coupled with a cooling fan to a certain wind speed to strengthen the cooling heat. In some large-scale equipment power devices are also used in the flow of cold water cooling plate, it has a better heat dissipation effect. Heat dissipation calculation is in certain working conditions, through the calculation to determine the appropriate heat dissipation measures and heat sinks. The power device is mounted on the heat sink. Its main heat flow direction is from the tube core to the bottom of the device, and the heat is dissipated to the surrounding space by the heat sink.
Small electronic heat sinks (or heat sinks) are made from aluminium alloy sheet by stamping process and surface treatment, while large electronic heat sinks are made from aluminium alloy extruded to form profiles, and then made by machining and surface treatment. They are available in various shapes and sizes for different devices to be mounted and for different power consumption. Radiators are generally standard parts, but also provide profiles, cut to length by the user according to the requirements of non-standard radiators. The surface treatment of the heat sink has electrophoretic painting or black oxygen polarisation treatment, which aims to improve the heat dissipation efficiency and insulation performance. It can be increased by 1015% under natural cooling and 3% under ventilation cooling, and the electrophoretic painting can withstand voltage 500800V.
Electronic heat sink manufacturers for different models of heat sinks to give the value of thermal resistance or to give the relevant curves, and to give the different thermal resistance under different heat dissipation conditions.
Calculation: A power operational amplifier PA02 is used as a low frequency amplifier. The device is an 8-pin TO-3 metal case package. Device operating conditions are as follows: operating voltage VS for 18V; load impedance RL for 4, operating frequency DC conditions can be up to 5kHz, the ambient temperature is set to 40 ℃, using natural cooling. Check the PA02 device data can be seen: quiescent current IQ typical value of 27mA, the maximum value of 40mA; device RJC (from the core to the shell) typical value of 2.4 ℃ / W, the maximum value of 2.6 ℃ / W.