PWM motor controls in standard and customised configurations

Paul Boughton
LCR Electronics is introducing two new digital PWM (pulse-width modulation) motor controls. Available in battery-powered and ac-line powered versions, the two controllers incorporate H-bridge circuitry with high-speed switching to produce precise speed and torque control, bi-directional operation and overload protection.

The high-voltage EC104 and the low-voltage EC106, with control methods for either two- or four-quadrant operation, are adaptable to many different dc brushed, shaded-pole and PSC (permanent split capacitor) motor applications, including appliances, pumps, compressors, blowers, conveyors and traction systems.

Onboard potentiometer and switch input options are provided for easy human interfacing. For applications requiring unidirectional dc brushed motor operation, the controls can also be simplified to eliminate unnecessary components and keep costs low. Other factory-installed options are a parking brake, coast, open-loop (coarse control without feedback) or closed-loop (+/-2 per cent RPM using feedback) control, and soft start to extend motor life.

Both the EC104 and EC106 boards can operate as a single-phase variable-frequency drive to adjust motor speed, making them suitable for use with ac motors with high starting loads and in-rush limitations.

The EC104 has an input of 120/240V AC and a typical load current of 3A that can be upgraded to 20A. Output can be configured for 150 or 300V dc. The EC106 has an input of 12 or 24V dc and a 5A maximum load current, also upgradable to 20A.

Competitively-priced, the controls operate at a de-rated temperature range of -20 to 85 degrees C and are available with an optional conformal coating for use in humid or wet environments. They are also Rohs-compliant and available in EMI-compliant versions.

Furthermore, the boards can be quickly and cost-effectively customised for specialised applications, and LCR's complementary EMI filters can be designed into a customised boards early in the process, thereby decreasing design costs and lead time.

Pricing starts at $35 (USD) for the EC104 and at $25 (USD) for the EC106 in quantities of 1000.

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