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Are transistors interchangeable?
So yes transistors are interchangeable, if the type (npn/pnp) and required specs match. If the current through a transistor was only 10mA and they have a part that can tolerate 1A, well, that’s a bit much, and you can find a part that is more suited to what the circuit it.
Can I replace a NPN transistor with PNP?
Generally, the PNP transistor can replace NPN transistors in most electronic circuits, the only difference is the polarities of the voltages, and the directions of the current flow. PNP transistors can also be used as switching devices and an example of a PNP transistor switch is shown below.
Are NPN and PNP interchangeable?
Answer: NPN and PNP transistors are interchangeable if you remember one simple rule: A bipolar transistor is essentially two back-to-back diodes with the base being the common connection.
How is the bd139 transistor different from other transistors?
Note: Complete Technical Details can be found at the BD139 transistor datasheet provided at the bottom of this page. BD139 is a NPN transistor hence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground and will be closed (Forward biased) when a signal is provided to base pin
What’s the difference between PNP and NPN transistors?
The difference this time is that we are switching power with a PNP transistor (sourcing current) instead of switching ground with an NPN transistor (sinking current). Sometimes the DC current gain of the bipolar transistor is too low to directly switch the load current or voltage, so multiple switching transistors are used.
What is the saturation region of a PNP transistor?
Therefore the transistor is switched “Fully-ON”. Then we can define the “saturation region” or “ON mode” when using a bipolar transistor as a switch as being, both junctions forward biased, VB > 0.7v and IC = Maximum. For a PNP transistor, the Emitter potential must be positive with respect to the Base.
How is the base voltage of a transistor biased?
To bias a transistor we have to supply current to base pin, this current (IB) should be limited to 1/10th of the collector current and voltage across the base emitter pin should be 5V maximum. When this transistor is fully biased then it can allow a maximum of 1.5A to flow across the collector and emitter.