# What is the fundamental difference between a DC step down chopper and a Buck converter?

#### Devika B S

Joined Mar 8, 2017
144
Both are used convert DC to DC : from a higher voltage to a lower voltage. I find that Buck converters have the same circuit in various sources. However, there are several circuits titles step down chopper. Is step down chopper a generic term for all DC- DC high to low voltage converter and Buck converter a specific type of step down chopper?

#### crutschow

Joined Mar 14, 2008
23,735
Possibly.
Can you post a schematic of, or link to, a "step down chopper".

#### BobTPH

Joined Jun 5, 2013
2,103
I have seen the term "chopper" used in welders. In that context, it is the same thing as a buck converter.

Bob

#### Externet

Joined Nov 29, 2005
1,419
Just bad slang... for both terms. As would also be 'duck' for 'buck' or 'switcher' for 'chopper'

#### Devika B S

Joined Mar 8, 2017
144
Possibly.
Can you post a schematic of, or link to, a "step down chopper".

This is the schematic as given in Wikipedia for Buck converter

#### crutschow

Joined Mar 14, 2008
23,735

This is the schematic as given in Wikipedia for Buck converter

#### DickCappels

Joined Aug 21, 2008
6,003
That is a buck converter.

Step-down applies to nearly anything that reduces the magnitude of a voltage and is not specific to switching regulator technologies. Linear regulators step down DC voltage step down transformers lower AC voltage, etc.

Chopper? A broadly used term but post a circuit of "a step-down chopper" and we will see whether our guesses are correct.

#### MrAl

Joined Jun 17, 2014
6,781

This is the schematic as given in Wikipedia for Buck converter

HI,

We need to see what you are calling a "Chopper". For example a helicopter is not a buck circuit

Sometimes a chopper is a circuit that converts a DC signal into an AC version that has amplitude that varies with the DC signal. So if you have say 2vdc input you may have plus and minus 2v square wave output. This kind of cicuit is used for various purposes and strictly speaking it is not the same as a buck because for one thing a buck is a power supply circuit while the chopper in this case is a signal processing circuit. The resulting "chopped" signal may be used in various ways, which includes filtering or transmitting.

There is a chance that you might call the part of the buck circuit that converts the DC input to a PWM signal a chopper, but calling the whole buck circuit a chopper is taking it a little too far i think.

#### Devika B S

Joined Mar 8, 2017
144

The above is a screenshot of a 'step down chopper' from electrical4u.com - a website I usually find reliable.

#### Attachments

• 607.5 KB Views: 1

#### crutschow

Joined Mar 14, 2008
23,735
The above is a screenshot of a 'step down chopper' from electrical4u.com - a website I usually find reliable.
You stated the screenshot you posted in post #5 was a buck converter from Wikipedia.

#### Devika B S

Joined Mar 8, 2017
144
You stated the screenshot you posted in post #5 was a buck converter from Wikipedia.
No, I sent another one exactly called ' step down chopper'.

#### MrAl

Joined Jun 17, 2014
6,781
View attachment 141927

The above is a screenshot of a 'step down chopper' from electrical4u.com - a website I usually find reliable.
Hello again,

Strictly speaking that is a chopper. It is not being used for anything though, so it can not be a buck circuit just yet. Add an inductor and capacitor and you get a buck. Add nothing and you have a signal processing circuit.

The phrase "step down chopper" is not really appropriate however as there is nothing yet being stepped down. It's just being chopped. If you USE it as a step down, then you need to have at least one more component added really two though. Then it becomes a step down circuit.

#### DickCappels

Joined Aug 21, 2008
6,003
It is common for people, especially new to a particular field to want terms clarified and occasionally make an error when asking a question.

#### MrAl

Joined Jun 17, 2014
6,781
It is common for people, especially new to a particular field to want terms clarified and occasionally make an error when asking a question.
Hi,

I agree. I think it is also good that they ask so they dont wonder forever. Some people i noticed wonder about things for a long time and never ask about it, until maybe years later.