![circuit analysis - What is the purpose of the D4 diode between base and emitter of PNP transistor? - Electrical Engineering Stack Exchange circuit analysis - What is the purpose of the D4 diode between base and emitter of PNP transistor? - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/AK2Vn.png)
circuit analysis - What is the purpose of the D4 diode between base and emitter of PNP transistor? - Electrical Engineering Stack Exchange
![BSIDE ESR02 PRO Transistor Tester SMD Components Checker Mega328 NPN/PNP Diode Resistor Inductor Capacitance ESR Meter with Tweezers - Walmart.com BSIDE ESR02 PRO Transistor Tester SMD Components Checker Mega328 NPN/PNP Diode Resistor Inductor Capacitance ESR Meter with Tweezers - Walmart.com](https://i5.walmartimages.com/asr/82e14d1f-02c7-493b-a1b0-5ece8db05118.3ed6ec31ff132e1820382d154f6bc017.jpeg?odnHeight=612&odnWidth=612&odnBg=FFFFFF)
BSIDE ESR02 PRO Transistor Tester SMD Components Checker Mega328 NPN/PNP Diode Resistor Inductor Capacitance ESR Meter with Tweezers - Walmart.com
![Bside Mosfet Transistor Capacitor Tester Inductance NPN PNP Diode Resistor LCR Meter MOS SCR ESR Checker Triode SMD Components Detector - - Amazon.com Bside Mosfet Transistor Capacitor Tester Inductance NPN PNP Diode Resistor LCR Meter MOS SCR ESR Checker Triode SMD Components Detector - - Amazon.com](https://m.media-amazon.com/images/I/71pxpnunt4L.jpg)
Bside Mosfet Transistor Capacitor Tester Inductance NPN PNP Diode Resistor LCR Meter MOS SCR ESR Checker Triode SMD Components Detector - - Amazon.com
![power supply - Confused about battery voltage warning circuit with PNP transistor and Zener diode - Electrical Engineering Stack Exchange power supply - Confused about battery voltage warning circuit with PNP transistor and Zener diode - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/ljrMT.png)
power supply - Confused about battery voltage warning circuit with PNP transistor and Zener diode - Electrical Engineering Stack Exchange
![bjt - Using a schottky diode to improve PNP transistor turn off time - Electrical Engineering Stack Exchange bjt - Using a schottky diode to improve PNP transistor turn off time - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/DFX0P.png)
bjt - Using a schottky diode to improve PNP transistor turn off time - Electrical Engineering Stack Exchange
![PNP Transistor Function & Mechanism | What is a PNP Transistor? - Video & Lesson Transcript | Study.com PNP Transistor Function & Mechanism | What is a PNP Transistor? - Video & Lesson Transcript | Study.com](https://study.com/cimages/multimages/16/npn_pnp.png)