Refer to MIL-PRF-19500/407 Silicon Semiconductor Device, NPN Power Transistor, Types covered: 2N3055, JAN, JANTX, and JANTXV. The highest curve to the right represents the maximum operating temperature of the 2N3055 and should not be used in the design.
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Use any of the three lower curves in the graph above, or select a line parallel to one of the curves.
![how to connect the 2n3055 transistor how to connect the 2n3055 transistor](https://2.bp.blogspot.com/-SXokspXa_MU/WAX7cCyX3II/AAAAAAAAA98/9hbo2jQaJuE3cgYBsFHk3Cc3_xzgStKIwCLcB/s1600/2N3055%2BMJ2955%2Btransistor%2Bamplifier%2Bfinal%2Bstage.jpg)
Temperature derating is a standard practice for engineers during circuit design. Sockets are available for a TO-3 package, but should only be used during design and testing. In any case for longest life use either of the gray curves. Fans may be used to induce forced air cooling which will greatly enhance operation over higher temperatures. Note that the curves indicate Case Temperature and applies to free-air. The two styles of heat sinks for a 2N3055 include Rectangular Shape, or Diamond Shape. Refer below for a graphic of one style of heat sink. Extrusion heat-sinks are by far the most common for power amplifiers, and allow the formation of elaborate two-dimensional shapes capable of dissipating large heat loads. Because the collector is connected to the case the device may be directly attached to a heat sink to allow higher temperature operation. Use the curve to determine the amount of power derating based on case temperature. Some vendors may provide a much stricter derating, as this MIL Spec indicates 34.2mW/C for temperatures over 25C. No power reduction is required for temperatures below 25C. 2N3055 Transistor Operational Power Derating CurveÄerate the power dissipation for the 2N3055 by 0.657 W/ 0C for any operating temperature above 25 0C. 2N3055 Applications General-purpose switching, power amplifiers and audio amplifier. Package, TO-3 metal diamond shape package.
![how to connect the 2n3055 transistor how to connect the 2n3055 transistor](https://i.pinimg.com/originals/d8/78/8e/d8788ed96df13d1e2a282a790679e52f.jpg)
2N3055 Temperature-Power Derating Curve and linearly equation.