What Is The Difference Between Solid State Power Supply And Normal Transformer Power Supply?

The solid-state power supply, also known as electric power converters, are electrical devices that normally supply electric power to an electrical load. Its main function is to convert electric current from a certain source to the right current, frequency, and voltage to power the load. Conversely, a normal transformer power supply is an AC-to-AC converter with no frequency transformation, and they cannot transform DC.

The power supply can either be in-built in the load appliances being powered or standalone pieces of equipment. Its other functions include; cutting off the current when there is an electrical fault, power conditioning to obstruct voltage surges, or electric noise on the input from getting to the load. They also limit the current drawn via the load to safe levels, storing energy, and power-factor correction. Sometimes they replace transformers to achieve smaller size, cost, and weight. When the replacement happens, they are often referred to as solid-state transformers.

A transformer power supply can actively regulate voltage and current. They are less complex, mostly achieving a higher lifetime and more sturdy as well as higher efficiency. In some cases, they are affordable due to their smaller manufacturing costs. Remember, simple transformer-rectifier compounds are not known as solid-state supplies, although they would be from a technical viewpoint. Some transformers can convert single–phase power to three-phase power and vice versa.

Difference Between Solid State Power Supply And Normal Transformer Power Supply

What Are The 3 Types Of The Power Supply?

They are different forms of power suppliers widely used today: unregulated, series-regulated, Ferro resonant, and switching-regulator types. The main difference includes cost, size, efficiency, maintaining constant voltage output, amount of ripple, and weight. 

Unregulated Power Supply

Unregulated power supply lacks inbuilt voltage regulators and is thus generally designed to produce certain voltage at a certain level output load current. Normally, they are the block wall chargers that convert AC into a smaller amount of DC. This is then used to power electronic household devices and thus the most popular power adapters. 

The DC voltage output depends on the internal voltage decreasing transformer and needs to be matched closely to the load’s currents. Meaning the output voltage reduces as the current output to the load adds up. With this kind of power supply, the voltage output differs regarding the size of the load. Usually, it has a capacitor smoothing and rectifier, though there is no regulation to steady the voltage. It is suitable for applications that don’t need precision even though they might have a safety circuit.


1. Simple circuit

2. Affordable

3. Durable


1. Voltage ranges with current load drawn

2. Perfect only for voltage or fixed output current

Regulated Power Supply

This is the most common power supply that has two essentials: the switching and the linear series. Even though the switching power suppliers are known by many to be the latest technology, they have been there for ages. However, due to new improvements in semiconductor elements, transformers and capacitors have become more reliable, affordable, and simpler than a while back. It’s perfect for an application that needs high efficiency, small size, and average best regulations.

However, the switching power supply is limited because it produces voltage noise and a spike in its output that can radiate RFI/EMI due to switching transients. Unwanted signals like these might interfere seriously with the right signals while masking others. Therefore, safely designed power supplies must include the bypassing, effective shield, and filtering to stop the generation of noise into the delicate circuit.

Linear-regulated power supplies are less efficient and larger than switching types, although it is cheaper. It is normally used by engineers needing a wide range of dynamic, high gain, low noise, and fast response for systems and laboratory power demands. 

Nowadays, there is also a growing number of uses that need smart linear power supplies. Those suppliers normally connect to controllers via the (IEEE-488 bus) to sum, integrate, range, step, and interact with the command loop of recent automatic test equipment systems (ATE).


1. High-quality power supplies with adjustable current or output voltage

2. Noise filtering

3. Consistent voltage and precision tuning


1. Complex

2. Sometimes costly

Ferro Resonant Power Supplies

This is another type of power supply where power regulation occurs in step-down or step-up transformer via core saturation means. When you compare with series regulated and switching power supplies, it’s less costly. However, they are not precisely regulated than the two. However, it generates sufficient and precise voltage for several applications.


1. Cheaper than switching and series-regulated power supplies

2. Produces sufficient and precise voltage for several applications


1. They are not precisely regulated when you compare with switching and series-regulated power supplies.

How Do I Know If My Solid State Relay Is Bad?

Relays are discrete devices normally used to enable low power logic signals to regulate a much higher circuit. It isolates the high power circuit while assisting in defending a lower power circuit by enabling a small electromagnetic coil to prevent logic circuits. There are different ways to test if your relay is bad. You need to check with an ohmmeter over the normally open (N. O) terminal if the control power is off. The relays need to open for you to switch to OL and closed 0.2 internal resistance of the ohmmeter itself if you have to apply the control power.

You can also use a multi-meter in diode-test mode if you need to confirm the findings. To do so, put in a diode test and check over A1(+) and A2(-). The meter will be subjected to apply a small voltage to ensure the semiconductors read and conduct the voltage on the screen. Typically, this checks the NPN transistor starting in the base (p) finally to emitters. For you to know if it’s bad, the meter will read OL or 0.   But when the relay is perfect, it will read 0.7 in the case of silicon transistor that is popular, and 0.5 for a germanium transistor (that is generally rare but available)

Is A Power Supply A Rectifier?

A power supply can act as a rectifier only if the input is alternating currents (AC) with direct current (DC) output. Therefore, it is not always that a power supply is a rectifier.  A rectifier usually converts AC to DC. So rectifier circuit generally takes the AC afterward, converting it into a positive DC output. Most power supplies, such as regular electrical output, generates AC voltage while several handheld tools and other devices use DC.  The rectifier is used to generate desired DC power in such an application.

For better understanding, a power supply gives power at a preferred voltage using a transformer and might and a rectifier convert it to DC. The power supply includes both the AC power supply and the DC power supply.

Does A Transformer Waste Power?

Unfortunately, it turns out that transformers consume power if it’s plugged into the wall whether or not they are connected to your devices. It’s also true they do waste power when powering your devices.

Normally a typical house has 5-10 small transformers plugged into the walls at all times. If you have felt some of them, you can attest they are warm, and that’s the wasted energy turned into heat. The power consumption is low though it does add up to the overall consumption depending on the number of transformers you have. 

Let’s say you have ten transformers, and each consumes 5 watts. That means you will have wasted 50 watts each day which could add up significantly in a year. Avoid all these by unplugging the transformers when you are not using them. You can also decide to power the device straight from the battery bank by getting rid of transformers which goes a long way in improving efficiency.

What Is Inside The Power Supply?

Here are some of the parts found inside a power supply;

1. Voltage regulator. This part minimizes the DC output, enabling the right amount of power, watts or volts, to be supplied to your computer hardware.

2. Transformer. Manages the incoming voltage by cutting it up or down.

3. Rectifier. It simply converts AC into DC.

4. Filter. Smooths out DC that comes out from your device rectifier. 

The order in which these internal power supply parts function is as follows; the first one is the transformer, followed by the rectifier, filter, and voltage regulator.

What Are The 4 Stages Of The Power Supply?

There are several types of power supply, and most of them are designed to convert high voltage AC to a desirable low voltage supply for electronics and devices. A power supply is normally broken down into different stages, and each performs a specific function, i.e., transformer, rectifier, smoothing, and regulator. Their function is as follows;

1. Transformer- cuts down high voltage AC mains into a low voltage AC.

2. Rectifier- converts AC to DC, although the DC output differs.

3. Smoothing- smooth the DC coming out from the rectifier.

4. Regulator- gets rid of ripple by setting DC output to a fixed voltage.

Which Is More Dangerous, AC Or DC?

Studies show that AC is 5 times more dangerous than DC. The frequency of AC is the major reason for its serious impacts on the human body. The 60 cycles frequency is an extremely harmful range. With this frequency, even a 25 voltage can easily kill a person. It causes severe contractions of the muscles and sweating, which reduces skin resistance. If one comes to contact with AC, it’s advisable to free the victim from the current as soon as possible since longer contact further reduces the skin resistance. 


While power is believed to be the backbone of every electronic system, the power supply feeds the system. Picking the correct supply might be the key variance between a device working at a consistent level and the other without consistent results. 

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