Friday, March 30, 2012

QTM12 PTC Axial Leaded Thermistor - QTI

These Thermistors from QTI are available in resistance at 25°C from 10 ohm to 40K ohm. Power rating for the QTM12 series is 0.5 Watts at 25°C. The Encapsulation of the Component is by plastic molding, the axial leaded part has a body length of 0.421" and a diameter of 0.155".

QTM12 PTC Axial Leaded Thermistor - QTI

QTM12 PTC Axial Leaded Thermisto - QTI

Some Specs

  • Positive Temperature Coefficient: 0.7% per °C
  • Thermal Time Constant: 60 seconds max in still air
  • Dissipation Constant: 2.5 mW per °C min in still air

From - Quality Thermistor Inc. QTI

2108 Century Way, Boise, ID 83709, USA

Monday, March 12, 2012

Offline Isolated Flyback LED Controller - LT3799-1

This chip for LED driving has a power factor correction, the critical conduction mode keeps transformer small. A opto-coupler for feedback is avoided by an innovative primary shunt monitor.

Offline Isolated Flyback LED Controller - LT3799-1

Features

  • Offline 4W to 100W+ LED Applications
  • High DC VIN LED Applications
  • Gate driver to drive an external high voltage MOSFET.
  • Typical power factors of 0.97.

20 Watt LED Driver using LT799-1

20 Watt LED Driver using LT799-1