2007-04-06 13:25:05 · 3 answers · asked by ahhong813 1 in Science & Mathematics ➔ Engineering
A bang-bang controller operates between two control limits, usually full ON and completely OFF. It can still be a proportional controller if it controls the duty cycle of the ON time versus the OFF time. The thermostat for a gas-fired home heating system is a bang-bang controller: the gas burner is either ON or it is OFF. Same thing with most home air conditioners: the compressor is either ON or OFF to cool or not.
2007-04-06 14:38:41 · answer #1 · answered by hevans1944 5 · 1⤊ 1⤋
It is an ON/OFF controller where the controller action is to either go from fully ON(100%) or fully OFF(0%). Its gets its name BANG/BANG because in some applications there is a jarring noise like water hammer as the system operates
( quickly opening and closing a valve for example).
An ON/OFF control also operates with some hystersis about the set point. For example a heater is set for 120F set point with 4degrees hystersis. This will cause the heater to turn on at 118F and shut off at 122F. This keeps the On/Off controller from chattering excessively if it were to try an keep exactly 120F
IT IS NOT a proportional controller. PWM is not ON/OFF control. A good example of an ON/OFF control is a thermostat for your HVAC system. Based upon room temp and the thermostats set point the system is either ON or OFF.
By contrast a proportional control (P) adjusts the system from 0 to 100% and any where in between. This type of system is usually operating continuously about a stabilized output based upon the systems load.
2007-04-06 23:52:17 · answer #2 · answered by MarkG 7 · 0⤊ 0⤋
It's a controller whose output is "on" or "off" - no analog-type variable output.
2007-04-06 21:45:39 · answer #3 · answered by virtualguy92107 7 · 0⤊ 0⤋