Browse Definitions:

bang-bang (bang-bang control)

Contributor(s): Matthew Haughn

Bang-bang control is a type of control system that mechanically or electronically turns something on or off when a desired target (setpoint) has been reached. Bang–bang controllers, which are also known as two-step controllers, on-off controllers or hysteresis controllers, are used in many types of home and industrial control systems (ICS).

An old-fashioned house thermostat, for example, uses bang-bang control. When the temperature drops to a predetermined low set point, the thermostat switches the heating system on. When the temperature reaches a pre-determined high set point, the thermostat switches the heating system off. Depending upon the set points, this can result in a fairly wide range of acceptable temperatures and cause the heating system to have a fairly long response time. This is why bang-bang controllers are sometimes referred to as hysteresis controllers -- the word hysteresis describes a lag in response to change.

In product development, bang-bang control systems can be contrasted with proportional control systems. A smart thermostat in a hotel room, for example, might determine when there is an error between the setpoint and the current value of the process variable (the room's temperature) and respond to the slight deviation by opening or closing dampers. Proportional controls are more exact and have faster response times than bang-bang, all or nothing controls.

Light switches and dimmer switches also illustrate the difference between bang-bang and proportional controls. A light switch, which can be either on or off, uses bang-bang control. A dimmer switch, in contrast, reduces or increases power to the lighting load in order to achieve a lower or higher light output and uses proportional control.

This was last updated in January 2018

Continue Reading About bang-bang (bang-bang control)

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.


File Extensions and File Formats

Powered by:


  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces.

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

  • pure risk (absolute risk)

    Pure risk, also called absolute risk, is a category of threat that is beyond human control and has only one possible outcome if ...


  • federated identity management (FIM)

    Federated identity management (FIM) is an arrangement that can be made among multiple enterprises to let subscribers use the same...

  • cross-site scripting (XSS)

    Cross-site scripting (XSS) is a type of injection security attack in which an attacker injects data, such as a malicious script, ...

  • firewall

    In computing, a firewall is software or firmware that enforces a set of rules about what data packets will be allowed to enter or...



  • business continuity and disaster recovery (BCDR)

    Business continuity and disaster recovery (BCDR) are closely related practices that describe an organization's preparation for ...

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...


  • volume manager

    A volume manager is software within an operating system (OS) that controls capacity allocation for storage arrays.

  • external storage device

    An external storage device, also referred to as auxiliary storage and secondary storage, is a device that contains all the ...

  • NetApp SolidFire

    NetApp SolidFire is a business division of NetApp Inc. that specializes in all-flash storage systems.


  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.