AC Tech Control System provides variable frequency drives that are suitable for any general-purpose application involving an AC motor. These variable frequency drives are available with full array of operation or functions and in-built variable digital/analog input functions to cater to wide range of applications. The variable frequency drives from AC Tech Control System are available with salient features like latest technology; super low noise; expansion of frequency range; upgrading V/F characteristics; enhanced I/O function; built-in variable digital/analogue input functions to suit wide array of needs; and compact structure. Some of the technical specifications of these variable frequency drives include ultra compact size; built-in `soft touch` control panel; full DC injection braking; integral dynamic brake; customized parameter selection function; program security lock; on-line programming; 8 pre-set speeds; switchable carrier frequency; selectable volts/hertz pattern; 3 skip frequencies bands; LED display; regenerative over voltage protection; local control panel; remote speed input 0-5 V, 0-10 V, 4-20 mA; ground fault protection; S-character acceleration/deceleration function; 2-stage acceleration/deceleration; arrival/running signal transistor output; low acoustic-noise design; and inverter models for quiet operation.