UPS PCB: The Ultimate FAQ Guide

If you are looking for any information about UPS PCB, the information if right here.

Whether you want to learn about the design, features, specification or any other aspect about UPS PCB – this is the right guide for you.

Keep reading.

What Is UPS PCB?

A UPS PCB is a circuit board that is designed to assist in provision of emergency power to a device in the event of power outage.

When the mains power or input power source fails, it provides the load with the required AC voltage inverted from storage batteries.



What Is  Mini UPS PCB?

This is a miniature version of the UPS PCB and provides uninterrupted power supply used to power 5V,9V and 12V devices.

An example of such devices is Raspberry Pi and they operate within a 1A to 2A range.

For power input, they usually contain a micro USB connector with a USB-A used for the power output.

A 5-pin header is used to offer the 5/9/12V output together with the signaling inputs and outputs.

The Mini UPS PCB can be turned off, on or be made to operate in a programmable mode by use of a three position switch.



A connected computer can be used to switch it off when operating under the programmable mode.

What Are The Different Types Of UPS PCB?

Intrusions in the electrical power supply appear in various forms such as voltage spikes, voltage dips and power surges.

Various types of UPS PCB designs can effectively counter all these. They are:

Standby UPS PCB

This type of PCB is also called the offline UPS PCB and is normally used on personal computers.

The line voltage is responsible for charging the backup battery that is served to a transfer switch through an inverter.

standby UPS PCB

Standby UPS PCB

When the main supply goes off, the standby power is brought online by the transfer switch. The inverter is normally dormant until a power failure occurs and that’s why it is called a Standby UPS PCB.

Line Interactive UPS PCB

This is the most commonly applied UPS PCB design whereby the mains power is supplied to the inverter via a transfer switch.

The inverter then feeds it to the load.

This design has an active inverter that operates in reverse when the main supply is on converting AC to DC power.

This potential is what is used to continuously charge the backup battery.

In the event of a blackout, the inverter operates in the normal direction after transfer switch opens.

Line interactive UPS PCB

line interactive UPS PCB

This enables DC power to be taken from the battery and supplied to the load after converting it to AC.

Double Conversion Online UPS PCB

This UPS PCB is the most preferred configuration for devices that have a rating beyond 10kVA.

It resembles the standby UPS PCB but with a difference in the operation of the inverter.

The primary main supply path is the inverter output while in the standby UPS PCB it is secondary path.

double convesation UPS PCB

Double conversation UPS PCB

The rectifier AC-DC Converter) is fed from the main supply and back to the inverter that converts AC to DC power thus charging the battery.

What Are The Different Types OF Inerters Found In A UPS PCB?

There are majorly three types of inverters that can be used as components of UPS PCBs. They are:

Sine Wave Inverter

Sine wave is the type of wave that can be found from the local power service provider or normally from a generator.

Any rotating AC machine normally has a generated natural product in form of a sine wave.

The main benefit of a sine wave inverter is that all electronics available in the market are sine wave compliant.

sine wave inverter

sine wave inverter

This inverter ensures that the UPS PCB performs to its maximum capacity and specifications.

Modified Sine Wave Inverter

The waveform of a modified sine wave inverter resembles the waveform of a square wave, but with an additional step or two.

Most UPS PCBs work very well with a modified sine wave inverter although there is a reduction of either power or efficiency.

A PCB USB with a reduced efficiency due to the modified sine wave inverter will consume more power (20% above normal).

modified sine wave inverter

modified sine wave inverter

This occurs because a moderate portion of a modified sine wave is of higher frequencies.

Square Wave Inverters

Square wave inverters are rarely used but they are the cheapest in terms of cost among all the inverters.

They can efficiently run simple UPS PCBs without any problem but not complex ones.

How is a UPS PCB Used In Power Source Management?

The UPS PCB has certain capabilities when it comes to the power source management. They include:

Automatic Start-Up/Shutdown Of Devices

By using a power management software together with the UPS PCB, devices connected to them can be properly shut down.

This is very helpful especially in the event of a power blackout.

Moreover, the devices that were shut automatically can be started up automatically again when power is restored.

This also assist in preserving data and pre-set parameters on the device in use.

Scheduled Operations

The UPS PCB can be scheduled to have its output turned on and off automatically once a day to conserve energy.

When it is off, all the devices connected to it will shut down automatically

What are the components of a UPS PCB?

Besides the battery that stores the charge but not on-board, the UPS PCB contains other components. The UPS PCB draws its power supply to the AC output from the batteries in the event of a power blackout.

The components of the UPS PCB include:

i. Rectifier: the rectifier is responsible for converting the AC voltage to the DC voltage.

It also recharges the storage batteries of the UPS PCB while sustaining the units float voltage.

It swiftly handles any overload in the circuit while buffering any kind of surge. It can handle a very wide range of fluctuations in the input voltage.

ii. Inverter: the inverter is an electronic device that can change DC voltage from the Lead Acid battery to a DC voltage that is stepped up.

The output generated from the inverter can be compared the voltage from the mains supply.

The AC-DC-AC conversion process and filtering ensures electrical noise, surges and spikes are smoothened out.

This leads to a final output of a pure sine waveform.

iii. Bypass: directly outputs the AC power

iv. Switch: circuit that switches between inverter output and bypass output


What Is The Importance Of A UPS PCB?

Modern operations do not allow for electronic assets and equipment to be left vulnerable to power shortage issues.

The UPS PCB ensures this in very many ways including:

Prevent Loss Of Time And Money:

Power outages that last even as much as a second can lead to unavailability of equipment and devices.

This will lead to costly downtimes and heavy losses with other related disturbances.

A UPS PCB ensures continuous supply of power which is uninterrupted.

This will safeguard data and ensure streamlined operations with normal downtimes devoid of disturbances.

Regulates Unstable Utility power

Power supplied from utility companies is always not clean.

This means that the power can have very wide variations which can cause significant damages to equipment and devices.

Most countries by law have absolute specifications for voltage variation ranges according to their standards.

This means that if a utility service is to provide 240V phase, they can deliver a range of between 220 to 250V.

The filters in a UPS PCB assist in regularizing such unstable power thus producing clean stable power.

Reduces Risk of Component Failure

Modern systems of storage, networks and various servers are composed of miniaturized component that are very delicate.

They are bound to falter or fail under certain power supply conditions like surges and variations.

The UPS PCB counters this by ensuring continuous supply of stable power.

Supplement Generators And Surge Suppressors

During power outages, a generator can keep devices and systems operational but they have a long startup time.

Generators also do not offer any kind of protection against power surges and related electrical disturbances.

Surge suppressors greatly assist with spikes in supply power but cannot assist in other issues such as loss of power.

Brownout and Undervoltage are also other disturbances that the surge suppressor cannot assist in preventing.

Constant Availability of Power

Before, devices in the Information Technology field played a heavy supporting role in that industry.

In modern times, information technology devices and equipment are fundamental to how all companies operate and compete.

When such systems are down, all the vital business process come to a halt and operations stopped.

The UPS PCB ensures constant supply of power to such devices thus preventing such catastrophes.

Power Cost Management

In recent years, the cost of power and cooling devices has really skyrocketed out of control.

People managing data centers have the responsibility of attaining high availability while in the process ensuring a reduction in the cost of power.

Modern technology has availed extremely efficient UPS PCBs that can greatly assist in attaining such goals.

These products were not available in the industry and were not even an option a few years back.

What Are The Accessories Required After Assembling A UPS PCB?

After assembly, the UPS PCB requires other accessories to carry out its functions effectively. Some of the considered accessories include:

UPS PCB Energy Storage

Many solutions for power protection derive their standby emergency power from batteries. They can be either sealed VRLA batteries (Valve Regulated Lead Acid) or VLA Batteries (Vented Lead Acid) also known as Flooded batteries.

Sealed batteries tend to be a less pricey but with a shorter lifespan as they wear out quickly. VLA batteries need specific professional installation and regular specialized maintenance.

Deciding on the type of battery to use majorly relies on cost and durability of the chosen batteries.

Lead Acid batteries are heavy and bulky in as much as they are the best suited for the data center severities.

Disposing them is also a major challenge because of the toxic chemicals they contain.


During a power blackout, the UPS PCB is only capable of sustaining the devices for a few minutes before shutdown.

Companies find it difficult to stay without powered IT devices even for an hour in modern times.

A generator has to be incorporated in the architecture of power protection in case power failure persists beyond expected time.

UPS PCBs can only provide very brief emergency power but generators can keep systems running for up to several days.

Power Distribution Units

A quality power infrastructure needs to have this essential component that distributes the power to load devices downstream.

The PDUs in use are rack-mount which allocates power to devices and individual servers.

Floor-mount PDUs provide primary power to the server racks.

Optional devices like individual breakers and surge suppressors can be used together with PDUs to observe the use of energy.

What Are The Methods Of Mitigating EMI in UPS PCB?

Signaling in electronic devices is affected, through radiation or induction, by Electromagnetic Interference (EMI) energy. The common techniques employed to mitigate EMI in a UPS PCB include;

Ground Plane

UPS PCB Circuits need a floating ground to work therefore the ground plane is the best form of protection against EMI.

The ground plane in an AC-DC converter PCB provides a 0-volt line of reference to the ground terminal of the power supply for the circuits return path.

Reducing EMI using ground involves common practices like:

  • Using a Multi-layered PCB
  • Splitting ground planes with caution
  • Connect decoupling capacitors or bypass to ground plane to reduce the return path current
  • Connecting split ground planes at single points only to create more loops thus increasing EMI

Trace Layout

Traces are conductive paths containing flowing electrons in an active circuit in any UPS PCB.

Common trace layout best practices include;

Avoid sharp Right-Angle Bends

Capacitance is increased greatly at 45° corner regions thereby altering the characteristic impedance causing reflections.

Skirting right angles can easily mitigate this kind of effect.

Routing Differential As Close As Possible

The coupling factor that conveys the influenced noise through to the common mode is intensified by this practice.

Separating The Signals

Traces with high speeds such as clock signals must be kept separate from signals with low speed.

AC signals should also be separated from DC signals.

Use Via wisely

The importance of Vias in routing is that they enable the use of many layers in a UPS PCB.

Adding inductance and capacitance into a UPS PCB circuit brings about reflections because of the change in characteristic impedance.

How Does A Parallel Process UPS PCB Compare To A Standby UPS PCB?

In the standby UPS PCB, the AC input from the main supply is used as the output and during a blackout, the inverter feeds the load using the batteries for power.

parallel process UPS PCB

Parallel process UPS PCB

There is a momentary breakdown of a few milliseconds in case of power outage.

In the parallel process UPS PCB, input AC power is supplied from the mains and the voltage corrected by the bidirectional inverter that absorbs the noise.

Since it is an online inverter, reliability and efficiency are highly enhanced.

standby UPS PCB

Standby USP PCB

What Are The Factors To Consider While Choosing A UPS PCB?

To ensure the selection of the correct UPS PCB for your project, certain factors have to be put into consideration. They include:


Depending on the energy efficiency required for the device, one can opt for either single, double or multi-conversion UPS PCB.

Based on efficiency, the single-conversion UPS PCB outdoes the double-conversion but with less protection.

This makes them suitable to handle loads that are susceptible to failure.

The standby UPS PCB considered the basis of single conversion UPS PCB, is the best bet for smaller applications like desktops.

The double conversion topology of the UPS PCB has the greatest protection levels but are less efficient.

They are normally preferred for use in the protection of systems that are mission-critical.

Multi-mode UPS PCB topology is the most expensive when it comes to cost compared to single or double conversion.

They are highly preferred by companies seeking to achieve both protection and efficiency in their operations.


The rating of a UPS PCB is the amount of load that the final UPS can support once assembled and is measured in Volt-Ampere (VA).

The following have to be considered when choosing the optimum rating:

  • A list of all devices that the UPS PCB can protect should be made
  • The volts and amps that the devices draw should be determined
  • The volts and amps of each device should be multiplied to get the VA value
  • All the VA values are then summed together
  • The sum is then multiplied by 1.2 to allow room for growth

The UPS PCBs ratings should be equal to or greater than the final number arrived above.

This may change if a precise load data for the devices being protected is available.

Battery Management

The most important part of the UPS PCB system is the system of energy storage, which is basically the battery.

UPS PCBs charge the batteries by continual trickling which impacts the battery negatively.

It tends to degrade the internal chemical composition of the battery thus greatly reducing its service life.

Trickle charging is most suitable for flooded electrolyte batteries in large banks that support high power systems (above 500KVA).

Non-spillable batteries used by the UPS PCB for lower KVA devices use a different charging technique for longevity.

This technique involves the battery being ‘rested’ when the charger periodically turns off.

Remote Monitoring

A UPS PCB once assembled should be compatible with a system that can remotely monitor it. This is the best way of addressing any arising UPS issues and exercising preventive measures before they happen.

They monitor warning signs of future shortcomings such as an overheating battery or a deterioration of performance.

Real-time notifications are continually sent in the event of potential issues.

Scalability And Modularity

Assembling and implementing a strong UPS PCB protection system requires a lot of time and resources.

To reap maximum benefits from such systems, companies estimate a 3-5year timeframe of needs when choosing a UPS PCB for their projects.

If power requirements may significantly be large within that timeframe, then a UPS PCB that handles larger software is preferred.

What Are The Different Types Of Redundant UPS PCB Architectures?

Having UPS PCB redundant groups escalates availability because vital loads remain protected if one or several UPS PCBs fail.

The various types of Redundant UPS PCB Architectures are:

  • Zone: dedicated support is given by one or more UPS PCBs for a definite set of resources for the data center.
  • Serial: Several UPS PCBs are connected in such a way that the rest will compensate for the failure of one.
  • Parallel: redundancy is increased by using many parallel connected UPS PCBs which are independent. Failure of one is covered by the rest.

How Does Parallel Redundant Operation Occur In A UPS PCB?

In this type of operation, two UPS PCB units are connected in parallel in the same system of operation. On a normal operation, only one UPS PCB operates but in isolation with the other.

When they are connected in parallel, power can be supplied continually from one point in case of an error in the other unit.

This system of operation is what is known as the Parallel Redundant Operation system.

This will have an effect of increasing the number of components used in the UPS PCB compared to if one was used in isolation.

parallel redundant

parallel redundant

 However, the system reliability is greatly improved centered on the parallel system theory.

How Does Single Conversion UPS PCB Compare To A Double Conversion UPS PCB?

In a single conversion UPS PCB, the inverter gets current from the battery when the input AC supply exceeds the definite limits.

The AC input supply is then disconnected to avoid backfeed to the main supply from the inverter.

In double conversion UPS PCB, the primary main supply path is the inverter output while in the standby UPS PCB it is secondary path.

single conversation UPS PCB

Single conversation UPS PCB

The rectifier AC-DC Converter) is fed from the main supply and back to the inverter that converts AC to DC power thus charging the battery

double conversation UPS PCB

double conversatin UPS PCB

 What Are The Benefits Of A Multi-Mode UPS PCB?

The Multi-mode UPS PCB combines both the single and double conversion PCB technologies with improved efficiency and reliability.

Some of its benefits are:

  • To save cost and energy, it operates on the line-interactive mode under standard conditions. The voltage is kept within benign tolerances thus resolving common problems found in the mains supply.
  • In the event that the input AC power exceeds the stipulated line-interactive mode tolerances, then double-conversion mode will be automatically activated.

This will completely separate the devices from the main source of AC supply.

  • If the double-conversion tolerance is exceeded by the input AC power, the battery sustains the loads and keeps the system running.

Multi mode UPS PCB

Multi mode UPS PCB

Immediately the generator kicks in, the UPS PCB shifts to the double-conversion mode until the main AC power supply becomes stable.

 What Are The Disadvantages Of A UPS PCB?

The main disadvantages of the UPS PCB are:

  1. The cost of the battery used with UPS PCB is usually high making the whole system expensive
  2. Maintenance is a challenge especially when several UPS PCBs have been installed in a single IT system.
  3. The lead acid batteries are not durable and degrade with time
  4. Power consumption is high since the UPS PCB battery remains charged always

How Does A Line-Interactive UPS PCB Compare To An Online-Interactive UPS PCB?

In a Line-interactive UPS PCB, the inverter is maintained in-line by the UPS PCB.

The path of the batteries DC current is redirected from the usual charging mode and in the event of power loss, it supplies the current.

The on-line UPS PCB a ‘double-conversion’ technique getting an AC input and taking it through the battery strings after rectifying it to DC.

Line interactive UPS PCB

Line interactive UPS PCB

 For the protected devices to be powered again, the DC is inverted back to 120V or 230V AC.

In the line-interactive UPS PCB, its output is normally connected to the power inverter of the battery to AC.

A normal AC power input has the UPS PCB inverter operating in the reverse mode thus charging the battery.

In the online-interactive, battery source backup is charged by the input AC thus providing the power going to the output inverter.

This means that if the input AC fails, the transfer switch cannot be activated automatically.

If the input power of the line-interactive UPS PCB fails, the transfer switch is triggered to open and power flows into the battery from the PCB output.

online interactive UPS PCB

Online interactive UPS PCB

 Improved filtering and reduced switching transients are achieved because the inverter remains fully on and linked to the output.

How Has Flywheel Technology Replaced Valve Regulated Lead Acid Battery As A Source Of Energy Storage For UPS PCB?

Due to the toxic chemical levels of Lead Acid batteries and the tight regulations of disposing them, companies are finding alternatives for it.

The most convenient is the Flywheel which is a mechanical device fabricated around a very big rotating disc.

During normal UPS PCB operations, the disk is spin rapidly by electrical power.

When there is a blackout, the disc continuously spins by itself thus generating a DC power that is used by the UPS PCB as a source of emergency power.

The more the UPS PCB consumes the power from the flywheel, the more it loses momentum gradually. Less and less energy is produced until the Flywheel disc finally comes to a stop altogether.

Compared to Lead Acid batteries, the Flywheels are very light and smaller with easy maintenance and devoid of harmful toxins.

However, they can produce up to just a minute of standby power in as much as most utility power outages statistically last less than a minute.

Flywheel complementing Lead Acid batteries during brief power outages saves floor space with minimal maintenance costs.

The also extend the shelf life of the Lead Acid battery by reducing the frequency of its operation.

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