Key Ratio: Clarification

"Since no one showed interest in the topic in the 'General Technology' forum: what is the precise technical explanation behind the 'duty cycle'? I know what it generally means, but I'm not yet clear on the technical details. Is the actuator being sampled in a PCM-like manner, and does the duty cycle indicate the percentage of pulses within a specific time unit that had a value of '0' or '1'?"

Hello,

The duty cycle indicates the ratio of the time a valve is in the open state versus the time it is in the closed state. An absolute time value is not necessary because it can be derived from the percentage value when a specific time period is defined.
This is controlled and monitored by the control unit. The required duty cycle is typically stored in the control unit's characteristic curve (lookup table).

Typically, the relationship between "closed" and "open" is presented with "closed" being the starting point and "open" being the subsequent state, but there is also the reverse approach, where "open" is presented first and then "closed."
This information can be found in the documentation specific to the vehicle.

Duty cycle: 1% => This indicates that for every 100 seconds, the valve is open for 1 second and closed for 99 seconds.

75% would mean 75 seconds open and 25 seconds closed.


Although a solenoid valve only knows or can represent the on/off states of 0 or 1, the desired degree of opening can be achieved by adjusting the duty cycle.
Typically, the control unit performs this function using different frequencies (square wave pulses) (e.g., 1 Hz, 20 Hz, 100 Hz, etc.).


I hope this simple explanation is sufficient.

Best regards, Kristian.

Okay, so it seems my initial idea wasn't too far off!

Hi,

Here's a small additional note:

"Abtasten" is misleading in this context. Because nothing is being "scanned" or recorded, but rather controlled.

Especially the term "sampling" quickly brings the Shannon's theorem ( http://de.wikipedia.org/wiki/Nyquist-Shannon-Abtasttheorem ) to mind, and with it, primarily the frequency.

While the valves are also pulsed at a certain frequency, this frequency is irrelevant to the opening width and is usually not specified.

m;