March 15, 2022

Why Use MOSFET Transistors in Your Electronic Control System?

The MOSFET transistor is increasingly present in electronic systems. Explore its role and benefits for specialty vehicle manufacturers.

What is a MOSFET and what does it do?

A Metal Oxyde Semiconductor Field Effect Transistor (MOSFET) is a semiconductor device belonging to the family of transistors. In electronics, its function is to convey the necessary voltage to a load. In a way, they play the same role as a switch (such as a traditional electromechanical relay), but with advantages that often surpass the latter.

The western world has adopted this technology more widely than the rest of the world. However, many manufacturers of specialized vehicles or mobile equipment are still reluctant to abandon the use of conventional relays and migrate to completely electronic and self-protected control systems. The reasons are multiple: lack of understanding of the technology, simplicity of the current system to operate, power required too high or the perception that the technology would be more expensive. However, the opportunity remains and is more justified than ever, in particular for bodybuilders of emergency or public utility vehicles.

What are the advantages of adopting a power distribution controller equipped with MOSFETs?

Small, fast and silent

A power MOSFET is much smaller than a relay and can also be used as a fast switching device. Since it is non-mechanical in nature, it can provide much faster switching compared to relays. In addition, they are silent and do not indicate if they are activated.

Pulse-width modulation capacity

Pulse width modulation (PWM), is a method of reducing the average power delivered by an electrical signal. The average value of the voltage supplied to the load is controlled by turning on and off the switch between the supply and load at a rapid rate. The longer the switch is on versus off periods, the greater the total power supplied to the load. The MOSFET makes it possible to control this output power by varying its activation and deactivation times, something that a simple relay cannot do. PWM is commonly used to control the speed of a DC motor or the brightness of lighting.

Protection against overcurrent and lifespan

Another great advantage is that some transistors are protected in the event of a short circuit. For example, at PRAN Systems Inc., most of our products with transistorized outputs are protected by circuits that occupy this specific function. It is nevertheless possible to integrate the same kind of short-circuit protection on relays, for example by adding a protection device such as a fuse or a circuit breaker. However, when a short circuit occurs, the protective device will open and potentially break, depending on the type of device used. Added to this is also spinning. In addition, the MOSFET can send a message to warn in the event of a problem in the system via a display. Finally, relays have a faster wear.

Price and other benefits

Generally speaking, MOSFETs are cheaper. Over time, we also notice that they become more and more powerful. In addition, for control system integrators there are the added advantages of having a system that is faster to install, configurable most of the time and that requires less wiring. Once the technology is adopted, it offers additional possibilities related to safety, reduces the required space of the electrical system in the vehicle and can even offer more functionality or intelligence.

What future for insulated-gate field-effect transistors?

The growth of power semiconductors will continue in the coming years in almost all industries. The arrival of COVID-19, however, has shifted the demand for MOSFETs and microcontrollers towards the production of consumer electronics, causing headaches for automotive and special equipment manufacturers. Despite this slowdown, all indicators are positive that growth is expected for the next five years. Therefore, unless you have a vehicle requiring very high operating voltages or currents, transistorized controllers remain the solution of the future for bodybuilders and integrators of electrical systems for special vehicles of all kinds.

If you are a special vehicle manufacturer and would like to know if a transition to a completely electronic and self-protected control system would be suitable for your application, write to us today! It will be our pleasure to assist you in your projects and support you in your transition.

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