Rev 2.0 Testing

DCDC Testing from Jan 22, 2022. Note that ‘the converter’ refers to the DCDC converter being tested, and the ‘DC power supply’ refers to the power supply being used to supply power to the converter.

Operating Characteristics

Measured using a Keysight N8700 Series DC power supply and a Rigol DL3000 Series DC electronic load with sense wires on both devices. The converter was tested from 80V-150V at 10V increments, loading the output from 1A-17A at 0.944A increments for each voltage level. Measurement points were the average of 5 samples after discarding the first and last sample from the total of 7 that were taken at 1-second intervals. The fan was operating at 12V for the duration of the test.

Discharge Circuit

This measurement may be incorrect. The voltage at the input was measured after turning off the output of the power supply from 140V. The output was attached to the input of the electronic load, but the load was not on. I am unsure whether the output of the DC power supply has output capacitors and a discharge circuit of its own, which may have also discharged the capacitors on the DC converter. The voltage at the input takes 1.7s to fall from 140V to 60V, and a total of 2.3s to fall to near zero.

Inrush Current

Since we did not have a current probe to measure the inrush current, it was estimated by measuring the time taken for the capacitor to charge. The DC supply was powered on at 140V with a 23A limit. The temperature of the ICL before turning on was not measured but it was not noticeably warm to the touch. From visual inspection, the voltage at the input rises from 12V to 57V in 5ms. Assuming an input capacitance of 2000uF, the average current over that period is 18A.

Input Ripple

The voltage ripple was measured at the input of the power supply to see if any noise was emitted out of the converter’s input to the DC supply. The converter was operating at a 15A output with a 140V input. The following was taken at the input connector with a ground spring to minimize EMI. Nevertheless, there is still the possibility that there was significant interference with the signal. The signal was AC coupled to the scope with a 20MHz bandwidth limit.

Over-Current

OCP was tripped at 18.6A.

Output Ripple

The following measurements are probably highly inaccurate. They were taken with a ground clip rather than a ground spring, resulting in noise being picked up by the probe from the switching converter. Actual values will be smaller. The signals were all AC coupled to the scope with a 20MHz bandwidth limit.

95V

140V