Bertec Corporation

Bertec’s external amplifiers for use with the force plates provide the user with three signal output options: digital (AM6500), analog (AM6501, AM6504) or dual digital/analog outputs (AM6800). The digital signal output can be directly plugged into the standard USB port of the personal computers without the requirement of an additional PC card for analog-to-digital (A/D) signal conversion. This plug-and-play technology allows a simpler installation procedure in a minimum amount of time. If you prefer an analog output, the force plate’s 16-bit digital output can be fed into an A/D board so that data can be collected using conventional techniques. Depending on application, either a fixed gain (AM6501) or an adjustable gain (AM6504 with 4 adjustable gains or AM6800 with 7 adjustable gains) amplifier can be used. These amplifiers enable the user to establish a trade-off between the measurement range and resolution of the force plates.

Digital data acquisition software, provided with the force plates as a standard item (with AM6500 and AM6800 output devices), enables the user to collect data quickly without the need of additional custom designed software. Upon request, software libraries and device drivers are available from Bertec so that users can write their own digital data acquisition software.

The AM6500 external converter transforms the digital output signal to USB format, which can be directly connected to the computer using a standard USB cable. The output is a standard female B-type USB connector. Next to the connector are two LED lights. The bottom light is on when the unit is powered via the transformer, and the top light comes on if the unit is connected to the USB port of the computer. The input to the module is via a 9-pin D-Sub connector located next to the power input.

AM6500 signal converter is accompanied by the Digital Acquire™ data acquisition software, which enables collecting data directly from the USB port of the computer (no A/D converter cards are required) and saves it to the hard disk as a column-formatted text file. The Digital Acquire™ software is provided free of charge with AM6500.

PDF Brochure: AM6500

The AM6501 external analog signal converter is utilized to convert the digital output of the plate to an analog signal using a fixed, gain value (gain=1). This amplifier also provides an auto zero button to remove tare load offset. An external, universal power supply is used to provide power to the amplifier. The input to the converter is a 9-pin D-Sub connector located next to the power input. The output is via a 15-pin D-Sub connector. The 6 output channels provide an analog signal in the range ±5V. Six analog scale factors are provided with the force plate to convert the analog signals to force and moment units.

PDF Brochure: AM6501

The AM6504 external analog signal converter converts the digital output of the plate to an analog signal using four adjustable gain values (1, 2, 5, 10). The gain adjustment is via two dipswitches in the top plate. This amplifier has an auto zero button to remove tare load offset. An external, universal power supply is used to provide power to the amplifier. The input to the converter is a 9-pin D-Sub connector located next to the power input. The output is via a 15-pin D-Sub connector. The 6 output channels provide an analog signal in the range ±5V. Six analog scale factors are provided with the force plate to convert the analog signals to force and moment units.

The AM6504 amplifier provides a ±5 V full-scale calibrated analog output per rated load range for each of the six force plate channels. For example, if the force plate has a ±10 kN load range for the Fz channel, then for a gain of unity -5.00 V output corresponds to -10 kN and +5.00 V stands for +10 kN (i.e. a sensitivity of 0.5 mV/N). The analog gain used in data acquisition represents a trade-off between maximum load range and force plate sensitivity. If the same force plate above is used with an amplifier gain of 5, then the load range will be limited to ±2 kN. This means the plate now has an increased sensitivity of 2.5 mV/N.

PDF Brochure: AM6504

The AM6800 amplifier incorporates both analog and digital outputs into one unit. The gain of the analog output is user selectable and has 7 different settings (1, 2, 5, 10, 20, 50, 100). A single gain selection switch is provided for all 6 output channels. A three-digit LED display on the front panel shows the gain setting. The auto zero button is utilized to remove tare load offset from each channel output. The mains power input is a universal input with a range of 100-240 V, 50-60 Hz. The digital output is a USB signal.

The AM6800 amplifier provides a ±5 V full-scale calibrated analog output per rated load range for each of the six force plate channels. For example, if the force plate has a ±10 kN load range for the Fz channel, then for a gain of unity -5.00 V output corresponds to -10 kN and +5.00 V stands for +10 kN (i.e. a sensitivity of 0.5 mV/N). The analog gain used in data acquisition represents a trade-off between maximum load range and force plate sensitivity. If the same force plate above is used with an amplifier gain of 5, then the load range will be limited to ±2 kN. This means the plate now has an increased sensitivity of 2.5 mV/N.