How to replace relay transistor output with field-effect transistor and the difference between relay output 2

5. Volume: FET has a compact size, suitable for compact circuit applications, while relays are larger and take up space.

Now, let's take a look at how to use FET instead of relay. Firstly, you need to choose the correct FET. The parameters you need to consider include maximum drain source voltage (VDS), maximum gate voltage (VGS), threshold voltage (Vth), maximum continuous leakage current (ID), total power consumption (PD), and switching speed. You need to choose an FET that can meet your power supply voltage, load current, and switching frequency requirements.transistor

Secondly, you need to design an appropriate driving circuit. This typically includes a BA3123F-E2 resistor voltage divider to limit the gate voltage, a capacitor to filter noise, and a diode to protect the FET from damage caused by reverse voltage.

Finally, you need to connect your FET correctly. The source should be connected to ground, the drain should be connected to the load, and the gate should be connected to the driving circuit.transistor

As for the difference in output, relay output is mechanical in nature, that is, the current is turned on and off through physical contact, while the output of field-effect transistors is electronic in nature, that is, the current is turned on and off by controlling the flow of electrons. This results in FET having faster response time and higher switching frequency than relays.

Overall, although FET cannot directly handle high currents and voltages, it can effectively replace relays and provide better performance in many applications by using appropriate driving and protection circuits.transistor