| abstract |
A controlled gain amplification system adapted for use in a seismic data acquisition system including controllable input and output gates, a plurality of cascaded operational amplifiers, a vernier amplifier having several selectable predetermined gains for amplifying analog signals received from any one of the cascaded operational amplifiers to produce an output analog signal having an amplitude within a predetermined amplitude range, a reset amplifier for clamping the cascaded operational amplifier outputs to a stabilizing voltage level removing spurious signals from the output analog signal, a comparator and a control means for controlling in response to the comparator the transmission of the analog signal between the components forming the controlled gain amplifier, concurrently selecting the gain of the vernier amplifier and enabling the reset amplifier to clamp the each operational amplifier output to a selected voltage level is shown. |