Rectifier vs Power Supply: What’s the Difference and Can They Replace Each Other?

Good morning.

We have a question, maybe naive, but we are wondering about one thing.
1. What is the difference between a rectifier and a power supply.
2. Is it possible to replace (and in what applications) the power supply with a rectifier and the rectifier with a power supply?

Please explain it in layman's terms, like to a simple peasant, because that's what I am.

1. One thing is intertwined with the other.

Commonly, a rectifier is a device used to charge starting batteries. Rectifiers usually do not have any stabilizer or filter. The rectifier is composed of a voltage-step-down mains transformer and rectifier diodes.

Technically, a rectifier is a device used to convert alternating voltage into pulsating voltage. Most often it consists of several semiconductor diodes.

A power supply is a device used to power another device. Usually, power supplies have a built-in mains or impulse transformer, voltage stabilizer and filters.

Here is an explanation of how rectifiers work Link

2. Yes, you can, but it is important not to exceed the ratings of the power supply and power supply device.

The rectifier can be replaced with a power supply, but not the other way around.

My friend Tadeusz_D You're a bit off the mark
The standard, most popular rectifier consists of a transformer and a rectifier bridge (diode, selenium, etc.) and does not have any voltage filtration. To turn it into a power supply, simply add an electrolytic capacitor to the output Then the tension will be smoothed out. I suggest learning the basics :)

A standard power supply for charging batteries is not suitable because it has no current limit and will be damaged very quickly :)

If we have a power supply, for example 15V 2.0A, we can charge the battery with it, but we must use a light bulb in series with the battery, which will limit the charging current without damaging the power supply or the battery. However, we must regularly check the battery voltage - when it reaches 14.4V, disconnect the power supply, the battery will be charged. Such charging will take a long time because the current efficiency of the power supply is not great, but it will actually be good for the battery, because batteries like long charging with low current.

Do you know Google?
Read/learn, and if you don't find it, ask here/otherwise I'll trash the post!

Quote:

Please explain it in layman's terms, like to a simple peasant, because that's what I am.

A long time ago, the matter was trivial, a "rectifier" was a device consisting of a transformer and a rectifier, but as usual, traders had to confuse the matter and now under the name "rectifier" you can find various complicated battery chargers that are simply not suitable for any other purpose. applications, many of them will not even start if you connect something other than a battery.

If you have an old-fashioned "rectifier", you can only power devices that can withstand such brutal treatment - after connecting the capacitor, the "12V" rectifier gives more than 16V.

Nowadays, a simple peasant should be careful, because most devices are not what they seem and everywhere they can find electronics that are not resistant to various unusual ideas (e.g. too high voltage).

PS There was a time when a simple guy could make a rectifier himself, buy a transformer and diodes and connect them. Today we have to start with a "lecture" that not every transformer is a transformer (the salesmen messed up again) :)

EDIT: For those who would complain: we consciously use the word rectifier in its colloquial meaning, inconsistent with what you can read in the dictionary.

To JestNick. A simple guy won't add an electrolytic capacitor to a rectifier because he doesn't know anything about it. He will take a rectifier supposedly for 12V, connect it to the device also for 12V and boom, because suddenly 18V will appear on the device. That's why I wouldn't recommend him a rectifier instead power supply. When it comes to replacing the rectifier with a power supply, I meant a power supply with regulated voltage and current limitation (unfortunately I did not write about it, sorry). Sometimes I used the power supply to charge the battery. I set the voltage to 14.4V and the current to 0.1 capacity battery.

We are farmers who have intelligence, but we have no knowledge. So please keep this in mind.
What can be connected to the power supply and to the rectifier?

Something called a rectifier may have a system adapted to charging the battery - including protection against reverse connection, signaling the end of charging... the power supply does not have this, which does not mean that you cannot charge the battery with it - you just need to be careful to do so this is correct, because there is no protection against the consequences of our mistake. And in general, the name "rectifier" in relation to the device that charges the battery is not correct - correctly, this name means the elements that pass current only in one direction (diode, bridge of diodes), which were used in such a device, and whose name transferred to your device.

Another thing - power supplies are different and cannot be interchanged. Many devices have power supplies that connect externally. Such devices need a specific voltage and current - another device may need a different voltage and if we replace their power supplies, one of these devices will probably be destroyed because it receives too much voltage. There may also be large differences in the quality of filtering - one power supply may provide voltage that is sloppily filtered, another one may be filtered thoroughly - if the former is used to power a device that is sensitive to interference coming from the power supply, it will probably not work properly. And some others can cope without filtering, and may even work properly if, instead of a power supply, a rectifier is connected to charge the batteries (as long as it is not one that tests the correct connection of the battery, because it may turn out that it will refuse to apply voltage to the battery). something that is not a properly connected battery).

In general, the rule should be that we use power supplies designed for them to power devices, and "rectifiers" designed for charging batteries of this type are used to charge batteries. And if we are to use something as a substitute, only when we know exactly that it is suitable.

And that's what I understand. Thank you Mr. JTA for your clarification. Finally, someone took us seriously and didn't argue with experts and...

What about connecting e.g. motors? We understand that we need to be careful about the capacity of the power supply/rectifier to ensure that there are "enough Amps and Watts"?

PS There is a box of beer cooled by a well waiting for Mr. JTA

You need to check whether the voltage matches (and the voltage that is really under load, not written on the housing), and whether the amperes/watts are enough (if the voltage matches, then sufficient amperes and watts should match each other, at least for a power supply that gives one voltage - because, for example, the 300W computer power supply that I have at hand has 300W, but only 10A at +12V, 25A at +5V, 14A at 3.3V, and some small currents on others, totaling over 310W , but on one at most 125.

And besides, there is the question of what such a power supply/rectifier actually provides, and what suits the motor - a DC motor may operate worse when powered by a pulsating voltage from a power supply/rectifier without a filter - have slightly lower efficiency/power, be noisy; perhaps it's even worse with a BLDC motor that has electronics inside, although these motors have systems that control their revolutions by supplying them with pulsating voltage - but maybe it is synchronized with the electronic system in the motor?

And as for the distinction between power supplies and rectifiers: the same (ideologically, because it has slightly different parameters) system, containing a transformer and rectifier diodes, can be called a rectifier for charging batteries, or a power supply for some device that has its own filtering capacitors inside. The difference remains in the purpose (if it is used to charge batteries, it is called a rectifier; if it is used to power a device, it is called a power supply) and the parameters adapted to this purpose.