P Channel Mosfet Power Switch Circuit

A 12v dc supply is connected to the gate of the mosfet through a push button switch.

P channel mosfet power switch circuit.

In this case use a p channel mosfet to turn the relay on from the arduino s i o pin. During switching a mosfet s source voltage must remain fixed as any variation will modulate the gate and thus adversely affect performance. This tutorial will explore the use of a p channel and n channel mosfets as a power switch and general transistor theory. Mosfets like bjts can function as electronic switches.

For example if you re trying to turn on a 5 volt relay with an arduino. To turn on the n channel mosfet requires a positive gate source voltage whereas the p channel mosfet requires a negative gate source potential. 2 shows how to use a p channel irf9630 mosfet to switch the positive side of the power supply to the light bulbs acting as a load. Mosfet as a switch.

Mosfet as a switch. An excellent use for p channel is in a circuit where your load s voltage is the same as your logic s voltage levels. We will understand the operation of a mosfet as a switch by considering a simple example circuit. If you are new and unaware about the working of a n channel mosfet check out this article.

2 p channel opto isolated mosfet switching circuit using irf9630 fig. The current necessary for the relay coil is too high for an i o pin but the coil needs 5v to work. This is a simple circuit where a n channel enhancement mode mosfet will turn on or off a light. A circuit for a typical high side switch using a p channel mosfet is shown in fig.

Mosfets are voltage controlled devices. Assume the device is initially off. There are a variety of configurations for driving the two mosfets with many different applications. Then the p channel mosfet is used to switch the positive supply to the motor for forward direction high side switching while the n channel mosfet is used to switch the negative supply to the motor for reverse direction low side switching.

We require only few components. Notice the similarities and differences between figs. This is for use with 5 volt micro controllers such as arduino. This switch will operate on the positive side of a power supply with a negative common.

In this project we will go over how to connect an p channel mosfet to a circuit for it to function as an electronic switch. The circuit implementation is simple. Firsly in fig 4 6 13 the resistor r4 whose purpose is to discharge any remaining potential on the gate at switch off is now connected to the positive supply rail instead of to ground. The input opto coupler and q1 operate the same as fig.

N channel mosfet characteristics and working.