What Are The Importance Of Switch Mode Power Supply?

Connectwell is a well-known Switched-mode power supply manufacturer in India. All the Electronics devices in the control panel are power by a DC power supply and the utility supply is an AC supply. To convert the AC onto DC a switched-mode power supply is used.

Traditionally Linear mode power supplies were used for converting AC mains to DC power. The linear mode power supply contained the linear transformers to step down the voltage. This generates heat and results in power loss.

The switched-mode power supply does not use the linear transforms instead uses the high frequency to switch the power and then step down the voltage.


Following are the advantages of the SMPS-

  1. Size: Due to the use of high-frequency transformers the size of the SMPS is small. All kinds of active and passive components are used which reintegrated circuits.
  2. Cost: Due to the lightweight and less in size the cost of the SMPS is less.
  3. High efficiency: The switching action means the series regulator element is either on or off and therefore little energy is dissipated as heat and very high-efficiency levels can be achieved.
  4. Low heat Dissipation: Due to the high frequency switching it does not have any heat losses.
  5. Compact: As a result of the high efficiency and low levels of heat dissipation, the switch-mode power supplies can be made more compact.
  1. Costs: one of the points that make switch-mode power supplies very attractive is the cost. The higher efficiency and the switching nature of the design mean that the heat that needs to be reduced is lower than that of linear supplies and this reduces costs. Long with this, the switching nature of the supply means that many of the components are lower cost.
  2. Flexible technology: Switch mode power supply technology can be used to provide high-efficiency voltage conversions in voltage step-up or "Boost" applications or step down "Buck" applications
  3. Weight: Traditional Linear power supplies were designed with transformers, As transformers are heavy and bulky the power supplies were heavy. In addition to this, a larger Heatsink is required due to large heat dissipation. Whereas the SMPS is designed with high-frequency transformers which are less bulky and compact, and the regulator is designed with a smaller heatsink due to the less heat dissipated.
  4. Wide Input Voltage range: Compared to the linear power supply it does not design the transformer on the voltage instead the transformer is designed on the frequency of use. The input voltage won’t affect the transformer performance. Due to which the SMPS can be used with a wide input voltage range.
  5. Better power factor: Step down transformer causes the loss and this loss converts into heat, due to which the linear power supply has less power factor. Instead in SMPS switching is employed due to which very there is no apparent power causes the best power factor.
  • Most Important Things Need To Be Considered Before Selecting The Switch Mode Power Supply 

Select a model of Power Supply according to your application. Following are some of the points which need to be checked before selecting the SMPS.

  1. Output Supply: Check for the required DC voltage for your system and accordingly selects the SMPS with respective output voltage. Calculate the required current by adding the current requirement of each instrument it is powering up. Select the SMPS with 1.2 X required current rating.
  2. Input Supply: Every industry or every country has a different power supply system check with the datasheet of the SMPS whether the selected SMPS can be used with regional power supply.
  3. Mounting methods: The industry offers a wide range of power supplies with various mounting arrangements. Check with your system before selecting the right mounting arrangement. 
  4. Approvals and Safety standards: ISO or IEC has prepared the standards for manufacturing and quality testing the SMPS; check whether the selected SMPS has proper approval.
  5. Temperature Ratings: Many times the failure of the electronics instrument is caused due to the temperature issue. Check the control panel ambient temperature before selecting the SMPS.
  6. Size and weight: SMPS are offered in different sizes and weights according to the different manufacturers and mounting arrangements. Check whether the selected SMPS fits in your available system.
  7. Warranty period: Check for the guarantee and warranty clause of the power supply before selecting the SMPS.
  8. Service and support: Check for service and support for the SMPS, as this shall reduce your downtime after the failure of the power supply.
  9. Additional Features: Following are some of the additional features that need to be checked-
  10. Different operating methods

            I] Parallel operation

            II] Series operation

Check the selected SMPS can support parallel and series connections whenever required.

  1. Overvoltage protection: prevents excessive voltage from being applied to the load when output voltage increases due to SMPS failure.
  2. Overload protection: Prevents failure of the SMPS due to the extra current being drawn due to more load connected.
  3. Alarm Output: The Relay contact is provided on the SMPS to get the SMPS condition.

Life Expectancy/MTBF Value: More the MTBF value better is the life of the SMPS, so select the SMPS wisely.


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