What is the difference between open loop gain and closed loop gain?
To achieve stable operation, op-amps are used with negative feedback. The gain of an op-amp without feedback is called the open-loop gain whereas the gain of an op-amp with a feedback circuit is called the closed-loop gain. The open-loop gain halves when frequency doubles.
What is the meanings of open loop and closed loop?
The open loop system means the output of the system is free from their input. In the closed-loop system, the desired output depends on their input. The open loop system is called the non-feedback system while the closed loop is the feedback system.
When to use closed loop or open loop?
Open loop is when the ECU is not referring to the o2 sensor for feedback. Meaning that the o2 sensor might as well not be there, because the ECU is not using it to modify its timing and fuel maps. Closed loop is when the ECU does refer to the o2 sensor for feedback.
How to tune closed loop and open loop O2?
1. The Percent (%) of fuel that can be added or subtracted from the fuel map. 2. The coolant temperature when closed loop o2 will begin. 3. The engine RPM when closed loop o2 will begin. 4. Conditions when closed loop o2 should be turned off. 5. The target A/F value based on load or MAFcfm, and engine speed.
When to use open loop or closed loop fuel control?
Open loop STFT is used on some PCM’s when the O2 sensors are showing signs of operation (O2 Readiness), however the closed loop enable ECT has not been reached. In this mode the STFT’s may function. The final mode is Closed Loop and in this mode the full closed loop fuel controller is operational.
What happens when a car is in closed loop?
If the computer is in closed loop and it’s not getting the expected readings from the oxygen sensors, it will self adjust and add or subtract more or less fuel to achieve the expected emissions readings. Fuel trim readings can be short term or long term. Fuel trim readings are constantly changing.
What’s the difference between closed loop and open loop?
The closed loop term is used because it’s the point where the computer is basing it’s air/fuel mixture calculations on readings from all the sensors. In other words, it’s “closing the loop.”
Open loop STFT is used on some PCM’s when the O2 sensors are showing signs of operation (O2 Readiness), however the closed loop enable ECT has not been reached. In this mode the STFT’s may function. The final mode is Closed Loop and in this mode the full closed loop fuel controller is operational.
If the computer is in closed loop and it’s not getting the expected readings from the oxygen sensors, it will self adjust and add or subtract more or less fuel to achieve the expected emissions readings. Fuel trim readings can be short term or long term. Fuel trim readings are constantly changing.
When to use open loop or closed loop ECT?
Open loop STFT is used on some PCM’s when the O2 sensors are showing signs of operation (O2 Readiness), however the closed loop enable ECT has not been reached. In this mode the STFT’s may function.