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The MOSFET in Power Electronics

Wed, 07/01/2026 - 7:37am by deadmin

Power Electronics
The MOSFET in Power Electronics

delabs Notes - In a Circuit Module, if all Power and Signal Polarities are reversed. All NPN to PNP, All N-Channel to P-Channel and Vice Versa. All Diodes and Caps too turned around. This Topsy Turvy or Mirror Design ought to work in Theory. It has worked for some circuits in practice too in my experience. ? 

Some believe that N-Channel is more Robust than the P Type. In Bipolar Transistor NPN is more trusted for the final output stages. The NPN Transistor and N-Channel turn-on by a Positive control bias. It may be inappropriate to say this mosfet is NPN or PNP. 

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BD139 and BD140 Complementary Transistors

Wed, 09/10/2024 - 3:20am by deadmin

Resources

This pair is my favorite when driving small solenoids or motors. SOT-32 and 12 Watts on Heatsink. This means any small solenoid, relay or DC motor can be controlled with this. I would use it upto 24V DC and max of 1A for applications of full on and full off. The pair is complementary NPN and PNP and well matched, this makes it suitable for the push-pull final stages of mini amps or small motor drivers.

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1N4148 High Speed Diodes

Tue, 01/10/2024 - 9:53am by deadmin

Resources

The 1N4148 is a standard silicon switching signal diode. Nominal values are Switching Speed 4 ns. Reverse Voltage 100V, Forward Current 200mA, 25nA leakage current. Room Temperature Specs. Package DO-35, DO-204AH. 500mW Power Dissipation. IN914 equivalent..

Datasheets of 1N4148 High Speed Diode.

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BC557 PNP Transistor General Purpose

Thu, 15/06/2023 - 6:29am by deadmin

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BC556, BC557 and BC558 PNP Amplifier Transistors are not only popular today but very ancient, it is used as a General Purpose device and a popular LED control in small products.

This Silicon device along with some others replaced Germanium Devices in Preamplifiers and Portable Transistor Radios  and Portable Tape Recorders. A Complement is the BC547B NPN General Purpose Transistor. Now for Specs 45V, 100mA, 200 beta approx.

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