Power Dissipation: 24 V, 0.5 A, θ=40 °C/W
A 24 V, 0.5 A component dissipates 12 W, causing a 480 °C junction rise at θJA=40 °C/W — a heat sink is mandatory.
How to use this tool
- Enter voltage across component, current through component, resistance and thermal resistance (θ_ja) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your power dissipated and the full breakdown beneath it.
Industrial 24 V linear circuits can dissipate significant power even at modest currents; always verify junction temperatures with a thermal calculation.
Frequently asked questions
- What is thermal resistance (θ_JA)?
- It is the resistance to heat flow from the component junction (hottest point) to the ambient air, in °C/W. A small IC might have θ_JA = 100 °C/W; a power transistor on a heatsink might be 5 °C/W.
- How do I derate a component for safety?
- Most manufacturers recommend derating to 50–70% of the maximum rated power at 25 °C. Check the derating curve in the datasheet for operation at elevated ambient temperatures.