![]() ![]() Data on the Test side of the Test and Cal cell, from 2 A pulses, at CA speeds of Norm (blue), Fast (red) and Fastest (green). The trace colors correspond to CA Speeds: green is Fastest, red is Fast, and blue is Norm.įig. Voltage is on the top set of traces and current is on the bottom set. Such current pulses always are applied with the Reference 3000. At 30 A, its power dissipation is only 2.7 W, so it is safe from misconnection and oscillation.įig. The connections were switched to the Test side of the Test and Cal Cell. Data using the CA Speed Fastest, comparing signal responses at 4 A (blue) and 8 A (red). There is still no evidence of slew-rate limitations.įig. 7) shows 4 A and 8 A pulses in CA Speed Fastest. ![]() Data at 8 A, using the CA Speed Fast (blue) and CA Speed Fastest (red). The red curve has a squarer response but ringing is seen on both the rising and falling edges.įig. The blue curve was recorded with CA Speed Fast and red curve was recorded with CA Speed Fastest. 6 shows the effect of CA Speed on 8 A pulses. The lowest current (2 A) used no 30k Booster the higher currents (4–12 A) added the Booster.įig. The curves show no evidence of slew-rate limiting.įig. The larger currents (4 A through 12 A) included the Booster. The smallest current of 2 A did not require the 30k Booster. 5) Gamry Instruments tested a range of current pulses. Reference 3000 Booster Current Pulses on 200 mΩ ![]() Data recorded to oscilloscope under same conditions as Fig. Data recorded through the E Monitor connector. The graph was recorded in CA Speed Fast.įig. 3 shows the voltage-versus-time curve of a 200 µs, 2 A pulse on the Calibration-side resistor. Oscilloscope Data on 200 mΩ Taken from the E Monitor BNCĪ BNC cable was connected between the Reference 3000 rear panel E Monitor output and the input of the oscilloscope.įig. Green are CA Speed Fastest, red are CA Speed Fast, and blue are CA Speed Norm. Colors correspond to different control-amplifier speeds (CA Speeds): The cell voltage is the upper trace, and cell current is the lower. Connections were made through the Reference 30k Booster, with the Reference 3000’s 3 A full-scale range.įig. 2 below shows 2 A current steps lasting 200 µs each. ResultsĢA Pulses on 200 mΩ Cell, Using the Framework™ Softwareįig. Some of the tests required use of a Tektronix 2024C digital oscilloscope instead. Most data were recorded using our signature Framework™ software. The faster the CA Speed is, the better time-resolution is achieved, but at the cost of stability in the amplifier. Many tests were performed at different CA (control amplifier) Speed settings. It does not require a fuse because it can safely pass 30 A currents. The Test side of the Test and Cal Cell is a 3 mΩ four-terminal resistor. Fast current pulses larger than the 2.5 A fuse rating will not blow the fuse if the pulses are short enough. The resistance of a sample fuse was measured to be 34 mΩ. The fuse protects the 1 W resistor from damage caused by excessive current flow. This side is a 200 mΩ resistor with a 2.5 A fast-blow fuse in the counter electrode lead. Most of the testing was done on the Calibration side of the Test and Cal cell. The cell connections used the standard cables supplied with the system: a 1 m current-carrying cable and a 1.5 m sense cable. A Gamry Reference 30k Test and Cal cell was connected to the booster in all tests. The tests were run on a Reference 3000 and Reference 30k Booster. This Application Note shows results of our own research into the characteristics of our equipment. Gamry Instruments uses the Calibration side of the cell to galvanostatically measure impedance spectra at frequencies up to 300 kHz with less than 2° of phase error. Minimal mutual inductance between the current-carrying and sensing circuits.Minimal inductance in the current-carrying connections.True four-terminal sensing on both the Test and Calibration sides of the Cell.The 30k Test and Cal cell printed circuit board was carefully designed for: Reference™ 3000 (left) with Reference™ 30k Booster (right), with Test and Cal cell (green).Īs a cell, we used our 30k Test and Cal cell. This combination of instruments is useful for running stress tests on batteries, by applying rapid, high-current pulses singly or repeatedly.įig. High-current Pulses for Battery Research Introductionįor those interested in determining the characteristics of batteries, especially by discharging them to see their changes in impedance, Gamry Instruments offers the Reference™ 3000 potentiostat plus our 30k Booster. ![]()
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