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High frequency currents measuring - HF probe for ampermeter

     I often needed to measure high-frequency currents, usually in range of 20 - 100kHz, when working with the switchning power supplies (SMPS), inverters and electronic ballasts. Normal multimeter measures only up to 400, rarely 4000 Hz. That's why I created this probe, which is used to measure currents with a much higher frequency. The probe is connected to a DC ampermeter or a multimeter set to DC-current range. The maximum current depends on the maximum current of Ammeter and the diodes. Bridge consisting of Schottky diodes (low voltage) rectifies the current and capacitor smoothes it. A classic diode connected in parallel in the forward direction to the capacitor protects against power surges and open circuit in the event that the current flowed without connecting an ammeter. When the schottky diodes are SR360 or SB360 and protective diodes are 1N5408, you can measure currents up to 3A.

Schematic of the HF probe for high frequency currents measurement.

PCB pattern and soldering plan, Temsi made according to my schematic (thank you). The files for download: PCB pattern in PDF for printer a soldering plan in Eagle.