The Gearing & Watson range of digital switching amplifiers comprises two models, the DSA1 and DSA4. These amplifiers provide very high levels of efficiency (better than 90%) with superior levels of performance. These amplifiers occupy little space and are suitable for driving shakers from all manufacturers, as well as other laboratory applications.

EMC has been a major factor in the design of the digital switching amplifiers. Full use has been made of Faraday cages, compartmentalization, filtered interconnections, segmented wiring, common mode chokes for symmetrical currents, mains filters, optical coupling of signals and screened cables.

The DSA series features low distortion, typically less than 0.3%thd, a wide bandwidth of 3Hz to 5kHz and a signal to noise ratio of better than -70dB. The DSA4 is supplied as a fully enclosed 19 inch instrumentation rack system. Each power amplifier system comprises a Control Unit, a number of 4kVA power modules, a power supply, a shaker de field supply and a shaker degaussing coil supply.

A Control Unit performs the housekeeping functions, providing user controls and displays to enable switch-on status reporting, management of a heavy duty power supply and the control of up to six power modules.