Automotive Osciloscope Duty Cycle Measurements

Using Picoscope 7 Automotive Software

Duty cycle is the ratio of time a circuit is ON compared to the time the circuit is OFF.

Duty cycle is expressed as a percentage of ON time.

A 60% duty cycle is a circuit that is ON 60% of the time and OFF 40%.

Many loads are rapidly cycled on and off by a fast-acting electronics which accurately control the output power of the load.

Example of duty cycle

A single lamp can be duty cycle-controlled to operate as a side light, or a brake light simply by increasing or decreasing the duty cycle.

Duty Cycle Simplified at the Touch of a Button

If the lamp is pulsed ON at variable durations (called pulse-width modulation), the duty cycle varies.

If it is pulsed ON for 0.05 seconds in a 0.1-second cycle, the duty cycle equals 50%.

If it pulsed ON for 0.09 seconds of that same 0.1-second cycle, the duty cycle equals 90%.

This can be displayed using an oscilloscope as a simple measurement.

PicoScope 7 Automotive Software makes this task easy.

Select measurements, the measurements are grouped into Amplitutue and Time.

Determine if the Duty Cycle to be measured is positive or negative.

Positive Duty Cycle Measurement

A positively switched circuit (one that switches the live to control the load) should use a positive Duty Cycle measurement.

Negative Duty Cycle Measurement

A negatively switched circuit (one that switches the ground to control the load) should use a negative Duty Cycle measurement.

Simply select the appropriate measurement and the Duty Cycle measurement will appear at the bottom of the screen.


Fill out the contact form for your Free copy of our basic Oscilloscope Guide. Updated for PicoScope 7 Automotive Software.

During our basic oscilloscope course, we show delegates how to use the zoom and measurement features of the Pico Scope for detailed waveform analysis.

This enables the technician to capture enough data in sufficient but with enough detail to diagnose component and wiring faults effectively.

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