LHBF-48X

Low Pass Bessel Filter (npi)
Description

The LHBF-48X is designed for processing small bio-electrical signals. The input voltage range is ±12 V and the inputs are protected up to ±100 V.  Two overload-LEDs indicate when the linear region of the amplifier is exceeded.  All inputs and the output are BNC-connectors.

The LHBF-48X is equipped with a differential input stage with an AC/O/DC switch for each input and an offset compensation. The gain stage allows the amplification of the signal from 1-1000 in 1-2-5 steps. The gain is selected by an ten-position rotary switch.

The amplified signal is applied to the output filter(s).  The eight-pole Bessel lowpass filter has sixteen corner frequencies (30 Hz - 20 kHz).  The output filter can be bypassed by using a toggle switch. Optionally, the LHBF-48X can be equipped with a single-pole Bessel highpass filter with eleven corner frequencies (0.3 Hz - 10kHz) and an OFF position.  A NOTCH filter (50/60 Hz) is also available. The position of the GAIN and of the FILTER switches can be read from monitor outputs (1 V/step).

 

Specifications

INPUT RANGE:  ±12 V; protected up to ±100 V

INPUT IMPEDANCE:  1 MΩ related to ground (other values possible), input capacitance: 30 pF

AC COUPLING AT INPUT:  corner frequency of 0.1 Hz (if AC /0 /DC switch at BNC connector is switched to AC)

DIFFERENTIAL INPUT:  CMR >90 dB

OFFSET COMPENSATION:  ±0.1 V, ±1 V or ±10 V by toggle switch and ten-turn potentiometer

LOWPASS FILTER:
            8-pole Bessel, attenuation:  -48 dB/octave, corner frequencies (Hz): 30, 100, 300, 500, 700, 900, 1.3k, 1.5k, 1.7k, 3k, 10k, 20k

HIGHPASS FILTER (Option):
            1-pole Bessel, attenuation: -8dB/octave, corner frequencies (Hz): 0.3, 3, 10, 30, 100, 300, 500, 800, 1k, 3k, 10k; OFF position

GAIN: rotary switch: 1-2-5-10-20-50-100-200-500-1000

OVERLOAD LED's: starting to light up at ±10 V

FULL POWER BANDWIDTH: >200 kHz

OUTPUT IMPEDANCE: 250 Ω

OUTPUT VOLTAGE: max. ±12 V, short-circuit protected

LOAD CAPACITANCE: max. 10 nF

GAIN / FREQUENCY MONITOR: 1V / step

POWER REQUIREMENTS: 230 V/115 V AC, 20 W

DIMENSIONS: 19" rackmount cabinet, 483 × 250 × 88 mm