Switch mode power supplies are used widely because they offer many advantages in terms of size, weight, efficiency, cost and overall performance.
Here, we’ll take a look of where switch mode power supplies (SMPS) work best and why.
Let’s start with the basics. What are they and how do they work? SMPS have become an accepted part of electronics. They are otherwise referred to as switch mode power converters or switchers. There are different elements to the technology.
SMPS generally indicates a term that can be connected to the mains or another external supply and used to generate power.
Switch mode regulator controller. Regulator integrated circuits don’t always contain the series switching element. If the current or voltage levels are high, an external series switching element handles the higher current and voltage levels better.
Switch mode regulator. This refers to the electronic circuit providing the regulation. A switch mode regulator is part of the overall switch mode power supply.
In a SMPS, regulation is undertaken by using a switching regulator. A series switching element turns the current supply to a smoothing capacitor, on and off. The series element is turned on by the capacitor’s voltage. If this is higher than needed, the series switching element turns off – if it’s lower, it turns on.
The Pros and Cons
The advantages of Switch Mode Power Supplies are:
Efficiency. Because the switching action means the series regulator element is either on or off, very little energy is dissipated as heat. This allows for high efficiency levels.
Size. The SMPS can be compact because of its high efficiency and low levels of heat dissipation.
Flexibility. SMPS can be used to provide high efficiency voltage conversions, step-up “boost” applications or step-down “buck” applications.
The disadvantages are the noise. Transient spikes will occur as a result of the switching action. These can migrate to all areas of the circuits powered by the SMPS if they are not properly filtered. The spikes can also cause electro-magnetic interference or RF interference which might affect other items of electrical equipment nearby. This is particularly true if they receive radio signals.
Switch mode regulators can be designed using a single, integrated circuit, but external components are usually required. Components will require space and add to the costs. SMPS also require expert design, so that they perform to the required specification.
Industry Applications
Switch Mode Power Supplies are used widely in computers. They convert the computer’s main or bulk supply down to lower voltages, for example, such as those needed by USBs, the random access memory or the central processing unit.
Power supply systems will rely on switch-mode power conversion for high-efficiency operation. A typical SMPS system might convert ac-dc (rectification), dc-dc or dc-ac (inversion). Such systems are widely used in high voltage/high power industrial applications such as:
- telecom systems
- servers
- base-station equipment.
But for applications where very low noise is required, linear regulator technology is still widely used.
SMPS are good for rail power supplies, for instance, because of their high efficiency and low working temperature. The short circuit protects against over load, over voltage and over temperature.
SMPS also work for street lighting. They will work in dry/damp or wet environments – and they are very reliable. The product featured here is compliant with worldwide safety regulations for lighting and it’s suitable for LED lighting and moving sings regulation.