Linear vs Switching Power Supply


There are two main designs for the DC power supplies: Linear DC Power Supplies and Switching DC Power Supplies. The traditional linear power supplies are typically heavy, durable, and have low noise across low and high frequencies. For this reason they are mostly suitable for lower power applications where the weight does not pose a problem, and applications that require very low ripple and noise. The switching power supplies are much lighter, more energy efficient, durable, and have limited high frequency noise (although the noise can be filtered out by good design). For this reason, the switching power supplies are not suitable for high frequency audio applications but are great for high power applications, and pretty much any kind of applications in scientific and industrial settings. Other than that, these two types are pretty much interchangeable for various applications, and they cost about the same to make. Switching power supplies are used more broadly nowadays than linear power supplies, we have seen some online seller making claims that the switching power supplies are not suitable for plating or ionization, but it is misleading and not true.


Linear DC Power Supplies.


Linear DC power supplies were the mainstay of power conversion until the late 1970’s. With the advancement of switching power supply technology, linear power supplies are less popular today but still find themselves indispensable in applications that require very low ripple and noise. A linear power supply uses a big transformer to drop voltage from AC line to much lower AC voltage, and then uses a series of rectifier circuitry and filtering process to produce a very clean DC voltage.  That low DC voltage is then regulated into the desired voltage level by a dropping the difference in voltage across transistor or IC (the shunt regulator). Typical applications of linear DC power supplies include but not limited to:

  • studio mixer/audio amplifier

  • low noise amplifiers

  • signal processing

  • data acquisition - including sensors, multiplexers, A/D converters, and sample & hold circuits.

  • automatic test equipment

  • laboratory test equipment

  • control circuits

  • anywhere that excellent regulation and/or low ripple is required


For three decades, Mastech has made variable regulated linear power supplies with exceptionally low ripple and noise, at a fractional cost of established brands. Our success has attracted a number of copycats with look-alike products. Over the last three years, we have adopted new designs that bring reliability and fault tolerance of a linear DC power supply to the next level. After three years of testing, we are happy to confirm that the new Volteq line of linear DC power supplies has met all of our expectations in terms of voltage and current regulation, noise, and reliability, and is the linear DC power supply of choice for most of our customers.


Need help finding the right product? Check out the products below or our Selection Guide.


Switching DC Power Supplies


Switching DC power supplies were first introduced in the late 1970's, today they are the most popular form of DC power supplies in the market due to their exceptional power efficiency and great overall performance. A Switching DC power supply (also known as switch mode power supply) regulates the output voltage through a process called pulse width modulation (PWM). The PWM process generates some high frequency noise, but enables the switching power supplies to be built with very high power efficiency and small form factor. With a good design, a switching power supply can have excellent load and line regulation. Typical applications for switching DC power supplies include:


  • general purpose use including R&D, manufacturing and testing
  • high power / high current applications
  • communications systems, mobile stations, network equipments, etc.
  • electroplating, anodizing, electroforming, electrophoresis, etc.
  • Battery charging and equalization for Lithium Ion batteries, marine and vehicle batteries
  • electrolysis, waste treatment, hydrogen generator, fuel cell applications, etc. 
  • DC motors, slot cars, aviation and marine applications, etc.


For three decades, Mastech has built the regulated variable switching power supplies with the least noise and ripple in the industry. Our switching power supplies are widely used in R&D and lab environment because of their exceptional noise performance. The design choice to minimize the noise does come with some drawback: slower response and more sensitive to reverse EMF from the load. As a result, the Mastech switching power supplies are not suitable for battery charging, anodizing, LED applications, electroplating (use as plating rectifiers) and anodizing, electrolysis, electroforming, hydrogen generation and any electrochemical applications.


Recognizing the shortcomings, we have launched in 2012 a new line of switching power supplies under Volteq brand to address the growing customer needs in battery charging, LED applications, DC motors, electroplating and anodizing, electrolysis & hydrogen generation, slot cars, automotive, aviation and marine applications. The Volteq switching power supplies, with built-in over-voltage and reverse-voltage protection, are tough as rock, and yet still provide excellent noise and ripple performance by employing the state of art technology.


Need help finding the right product? Check out the products below or our Selection Guide.



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