Thermistor delivers 680V for welding equipment

Ametherm announce a new PTC circuit protection thermistor with an industry-high voltage rating for inrush current limiting and overcurrent protection in applications such as welding equipment and plasma cutters with extremely high voltages from 480 V to 930 V.

The new MCL20 500100-A thermistor released today features a 680 V voltage rating and handles a maximum inrush current of 20 A at maximum peak voltage. The device offers resistance at 25 °C of 50 Ω with a tolerance of 20 %, a dissipation constant of 55.0 mW/°C, a heat capacity of 5.45 J/°C, and a thermal constant of 62 s. The thermistor operates over a wide temperature range of -50 °C to +150 °C.

The radial-leaded MCL20 500100-A offers easy PCB mounting. With a 19 mm diameter, 9 mm maximum profile, and 7.8 mm lead spacing, the thermistor provides designers with a more compact and cost-effective alternative to combining a power resistor, relay, and timer on one circuit to achieve the same functionality. The RoHS-compliant device is available with straight leads and outside or inside kinked leads.

“The MCL20 500100-A can withstand hundreds of hits of maximum inrush current without degrading,” said Eric Rauch, president and CEO at Ametherm. “The device offers a short reset time, and as a PTC thermistor a quick reset will not result in a large inrush current, as its resistance is already at a high state. The result is extremely high reliability and stability in high-voltage applications, all while saving board space.”

The MCL20 500100-A PTC thermistor is available direct or through distributors such as Mouser. Samples and production quantities of the device are available now, with factory lead times of seven weeks.