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What causes transistor to overheat?
The output transistors are getting hot because they are conducting too much current. The trick is to reduce the base bias in order to push the transistors more from class AB to class B amplifier mode.
What happens when a transistor gets hot?
If you try to share current from one resistor, one transistor will get more of the current, causing it to warm up, which drops the Vbe even more, which causes it to get even more current.
How much power does a transistor dissipate?
Small plastic transistor packages like the TO-92 can dissipate a few hundred milliwatts. The metal cans, TO-18 and TO-39, can dissipate more power, several hundred milliwatts. Plastic power transistor packages like the TO-220 and TO-247 dissipate well over 100 watts, approaching the dissipation of the all metal TO-3.
Do transistors heat up?
The transistor will only heat up if being over driven.. Either something is drawing too much current, you are demanding too much power, or it is being over clocked.. Normally it should only be warm, not a burning to touch feeling if you touch the transistor..
Why is my transistor overheating at more collector current?
At more collector current, the majority of the power delivered to your circuit is probably just being dissipated in the transistor. As already mentioned, you need a driver circuit or another transistor. You could also use a gate drive N-channel FET. That would give you even better performance than any bipolar you could find.
When do transistors dissipate power when fully on?
On to output transistors- in an ideal world, transistors do not dissipate power when they are fully on or fully off. To illustrate this we can use the classic example of an ideal switch:
How to calculate the power dissipation in a BJT?
Since a BJT is a three-terminal device, each of which may have a different current and voltage, for the purposes of power calculation it helps to consider the transistor as two parts. Some current enters the base, and leaves the emitter, through some voltage V B E.
Where does heat come from in a transistor?
However for some of these devices heat is a real issue that needs to be addressed– in particular the heat generated by semiconductors. In analog applications of semiconductors, heat will most often be encountered in voltage regulators and output transistors.