KBPW-240D PWM DC Motor Speed Control
Product Announcement from KB Electronics, Inc.
The KBPW-240D is a PWM (pulse width modulated) control in a NEMA-4X /IP-65 washdown and watertight enclosure designed to operate Permanent Magnet and Shunt Wound motors through 7.5 Amps DC. The efficient PWM waveform, operating at a switching frequency greater than 16kHz,provides almost pure DC to the motor (form factor <1.05). This provides high motor efficiency, whisper quiet operation along with less motor heating. This allows for a smaller, less costly motor to be used in most applications. Another advantage of PWM is higher output voltage (up to 130 VDC for 115 VAC lines and 220 VDC for 230 VAC lines), which provides increased motor speed.
The KBPW-240D contains pulse-by-pulse current sensing, which provides short circuit protection and prevents control damage due to commutator arcing. Permanent magnet motor demagnetization is virtually eliminated because current peaks are reduced to safe levels. In addition, the main power transistor is mounted to a heat spreader, providing enhanced heat dissipation. This eliminates over temperature cycles that cause premature transistor failure.
A unique feature of the KBPW-240D is its active bridge, which substantially reduces the AC line surge current during cycling of the AC line. This allows the control to be turned on and off rapidly without damage to critical components. The active bridge is coupled with a failsafe circuit that will shut down the control if the main power transistor shorts, preventing a dangerous high-speed runaway condition. Motor burnout is prevented with the Timed Current Limit circuit (TCL) by shutting down the control when an overload condition exists for a predetermined amount of time. A special AC line input circuit automatically adjusts the control for 115 or 230 VAC.
Standard front panel features include diagnostic LEDs (for power on, stop, and overload), Start/Stop switch, and Speed potentiometer. Other features include barrier terminal blocks to facilitate wiring, adjustable trimpots (accel, decel, max speed, min speed, current limit, timed CL, IR comp, and jog speed), customer selectable jumpers (motor voltage, motor current, timed current limit, and tach voltage), and an output run relay.
Optional accessories include Fwd-Brk-Rev Switch, On/Off AC Line Switch, Run-Stop-Jog Switch, Signal Isolator, and an Anti-plug Reversing Module. Quick-connect terminals are provided for easy installation of all accessories.