The new PQ1 Power Quality Relay monitors sags, swells, interruptions, and impulses as short as 500 nanoseconds. And, at $276 (qty 1), you can buy twenty for the price of a single traditional power quality monitor.

The PQ1 instantly adapts to any international voltage between 100VAC (Japan) and 240VAC (U.S. and Europe), and operates at 50 Hz, 60 Hz, and 400 Hz. Higher voltages, including utility distribution voltages, can be monitored through an external transformer.

Setting thresholds is easy with the PQ1’s built-in international standards: IEC, EN, CBEMA, ITIC, SEMI, MIL-SPEC, and many others.

The PQ1 carries the CE mark, and is TUV-certified. UL listing is pending.

A full datasheet can be downloaded from

The PQ1 Power Quality Relay’s normally-closed contacts open for 3 seconds each time a disturbance is detected – an ideal interface for counters, error logs, SCADA systems, and PLC’s. Latched LED’s give a visual indication, too, and maintain their state during power failures.

“This is the first step towards making large automated systems aware of power quality disturbances,” says Alex McEachern, recipient of Power Quality Magazine’s 2001 Mungenast Award. “The systems can then respond appropriately, often eliminating the need for huge and expensive power conditioning devices.”

Early applications include semiconductor manufacturing systems, aircraft automation, ultra-low-cost utility power quality recording, and elevator controls.

Sample quantities are available from stock. Engineering kits and data sheets can be ordered from

Power Standards Lab 3908 Adeline Street Emeryville, CA 94608 USA