Alternating Current (AC) vs Direct Current (DC), the guide for you

Ever wondered what are the currents that are running through your wires? This guide will walk you through the 2 types of currents; Alternative Current (AC), Direct Current (DC) and what it all means.

In this guide, I’ll be covering the essentials ranging from:

  • What are AC and DC
  • Differences between AC and DC
  • Converting AC to DC
  • Whether to use AC or DC
  • Applications of AC and DC
  • Coupling with AC and DC

AC vs DC

Alternating Current (AC)

  • A form of current that changes direction periodically, oscillating back and forth

Direct Current (DC)

  • A form of current that only flows in one direction, providing a constant voltage/current

What are the differences?

Most commonly produces sine wave Constant voltage/current tend to produce horizontal waveforms
Generated by Alternator, an electrical generator designed to produce AC Commutator
Rectifier, converts AC to DC
Batteries, through generation from a internal chemical reaction
Suitability for long-distance transmission Suitable, transmission loss is small Less suitable, transmission loss is bigger unless it’s high enough in voltage
Usages Less suitable for electronic products unless power is switched into DC through rectifier Suitable for electronic products
Safety Level Lower safety level
Alternating voltages can cause current to enter human body without closed loop
Higher safety level
Commonly found DC currents in electical appliances tend to be safer

Converting AC to DC?

Although AC and DC operate differently, they need not be operating as a standalone circuit due to the availability of an AC-DC converter.

The converter is called a rectifier, where it transforms AC input into DC output through reversing the directional flow of current.

AC vs DC, which should you use?

Long Distance Power Transmission:

  • AC: The ability to ramp up voltages through transformers results in lesser resistance in the wires which can provide efficient transmission of long-distance power
  • DC: High difficulty and cost to efficiently create high voltage DC

Winner: AC, the one that does the job if you’re looking to transmit power over a long distance

Ease of Usage/Simplicity:

  • AC: Simple to operate through the usage of wires and transformers for voltage adjustments
  • DC: Unable to conveniently convert voltages due to requiring complicated circuits

Winner: AC, the convenience and flexibility that it’s able to bring unravels its opposition.

Compatibility with electronics:

  • AC: Less compatible with electronics due to the directional changes of current
  • DC: More compatible with electronics as current flows reliably in one direction

Winner: DC, the solution to power your electronics.

Applications of AC and DC


Delivers power to:

Houses, Offices, Electric Motors, Generators

Lauren. (2017, July 17). AC and DC electricity made simple.


Delivers power to:

Electrical Appliances; Cell Phones, TV, electric vehicles, etc.

Lauren. (2017, July 17). AC and DC electricity made simple. 

Coupling: AC and DC

AC and DC can also be referred to as the Alternating (Capacitive) Coupling and Direct Coupling. Coupling allows you to observe the voltages and wavelengths of the power supply. Each form of coupling will result in differing results in data when plugged into an oscilloscope.

AC Coupling vs DC Coupling

AC Coupling DC Coupling
Only show and allow AC signals to pass through a connection Allows for both AC and DC signals to pass through a connection
Suitable for the following sensors:
ICP Microphones
ICP Accelerometors
Strain Gauges (Elastic or Dynamic behaviour only)
ALL ICP/IEPE transducers
Suitable for the following sensors:
DC Accelerometer
Strain Gauges

Start coupling with:

DSO Nano V3: A portable DC coupling capable oscilloscope for voltage measurements

The DSO Nano V3 is a simple to use and compact oscilloscope that meets the basic demands of users ranging from school lab tests, electric engineering, etc.

Product Features:

  • Portable and lightweight
  • Color display
  • Waveform storage and playback
  • 6 triggering modes
  • 200Khz Analog Bandwidth
  • Complete measurement markers and signal characteristics
  • Built-in Signal Generator
  • Accessories available
  • Open Source


Choosing between using DC and AC comes down to the purpose and requirements of your project. DC is recommended for powering electronic devices due to the nature of batteries being powered by DC current. On the other hand, the ease of where AC voltages can be modulated is still unmatched. With that said, both currents are indeed excellent in their field of area and it solely comes down to the user application in picking the right one.


October 2019