earckens
Junior Member level 2
I need to detect whether the duty cycle from a circuit drops below a certain value.
Frequency: 2kHz
Amplitude: TTL (0 to 5V)
Step response: an hour or more (it is a very slow system), this is not PWM (duty cycle may change very slowly).
Requirement: detect whether the duty cycle is lower then a adjustable value, most likely less then around 70% (but may also be blow 85% if possible to design a detection for that value).
Hysteresis is required, say about 5 to 10%.
When the duty cycle drops below the preset value a TTL output needs to be triggered. When the duty cycle recovers above the preset value+hysteresis the TTL output needs to be reset. Changes in duty cycle take several hours. However measurements take place once an hour only, during a time adjustable between say 5 seconds and 30 seconds.
A circuit with a flipflop and 2 comparators is my preference. And I want a hardware solution, no software with microcontroller: the circuit has to be universally used without need for software. at a later stage this circuit wil be used in a controller for further processing.
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Frequency: 2kHz
Amplitude: TTL (0 to 5V)
Step response: an hour or more (it is a very slow system), this is not PWM (duty cycle may change very slowly).
Requirement: detect whether the duty cycle is lower then a adjustable value, most likely less then around 70% (but may also be blow 85% if possible to design a detection for that value).
Hysteresis is required, say about 5 to 10%.
When the duty cycle drops below the preset value a TTL output needs to be triggered. When the duty cycle recovers above the preset value+hysteresis the TTL output needs to be reset. Changes in duty cycle take several hours. However measurements take place once an hour only, during a time adjustable between say 5 seconds and 30 seconds.
A circuit with a flipflop and 2 comparators is my preference. And I want a hardware solution, no software with microcontroller: the circuit has to be universally used without need for software. at a later stage this circuit wil be used in a controller for further processing.
Modify message