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High-voltage NPN transistor

MPSA42 Working Principle

Learn how MPSA42 works with an illustrated explanation and practical readings.

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MPSA42 at a glance

Follow the labeled connections and functional stages

MPSA42 working principle: illustrated functional stages, basic circuit and connections
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How it works

3 stages · Explore one step at a time

Step 1 / 3

Establish the off state

A 100 kΩ resistor connects base to emitter.

Step 2 / 3

Provide base drive

Apply 5 V through 4.7 kΩ.

Step 3 / 3

Limit the load current

The 470 Ω LED resistor sets current; the transistor does not regulate it.

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