Month: 2011-11-04

A fluxgate magnetometer – a prestudy

Response (lower trace) of the toroidal fluxgate to a sine wave of about 7 V amplitude (upper trace, heavily distorted because of the limitations of the signal generator) in the presence of an external magnetic field..

Just a few days ago I read up about variations in the magnetic field of earth and how these can be used to detect northern lights. Since there have been sightings of northern lights quite recently even in major parts of Germany I became interested in the topic. A common type of magnetometer is based… Continue reading A fluxgate magnetometer – a prestudy

…another watt saved…

The LED driver and the 20W LED.

A few days ago I posted my driver prototype for a 20 W, 700 mA, 32 V white LED. Under best conditions I reached 85% of power conversion efficiency between the 12 V input and the electrical power delivered to the LED. I was not satisfied and one of my suspicions were substantial losses in the power MOSFET. I… Continue reading …another watt saved…