Categories : Blogs
Last week we talked about MIN and MAX modes on the Power Probe 3 line of circuit testers. Those modes can be very helpful when diagnosing starting and charging systems. This week brings us to PEAK TO PEAK mode. This is a very useful mode. For the most part, the PP3 series main function is the DC Voltmeter. Although it is not a true AC Voltmeter, PEAK TO PEAK mode can read AC signals. Let me explain… Now a true AC signal constantly alternates between positive and negative voltage and the PP3, even in Peak To Peak mode, cannot read negative voltage, but it can read the positive pulses of a true AC signal. In reality, for most vehicle circuits we don’t have many true AC signals, but we do have a lot of pulsed DC signals from things like Wheel Sensors, Cam Sensors, and PWM controlled circuits. These are typically 5 or 12 Volt pulses and the advantage of PEAK TO PEAK mode is that it will display the true voltage of the pulses regardless of the pulse frequency or duration. PEAK TO PEAK mode does not average the voltage number like it would when using a traditional AC or DC voltmeter… if it is a 5.0V pulse the PP3 will show 5.0V, if it is 12V pulse it will show 12.0V, regardless of the frequency or duty cycle of the signal. In the final blog of this series, we will cover AC Threshold.