Burkhard Kainka (228)

1-10-2012 | It is often necessary to deal with tiny currents in the picoamp to microamp range when making measurements in ionisation chambers and other...

1-10-2012 | The radiation meter published in the November 2011 edition of Elektor is currently being used by many readers, mainly in making long-term me...

1-10-2012 | The principle of a (preferably) linear amplifier is straightforward: an audio signal modulates (varies in volume and frequency) the small ba...

1-09-2012 | In the previous instalment we worked with static flip-flops and Schmitt triggers. Now things get a bit more dynamic, with capacitors providi...

1-07-2012 | Relays or contactors are often used to switch AC-powered inductive loads such as motors, valves or electro magnets. When the device is switc...

1-07-2012 | Energy saving is all the rage, and here is our small contribution: how much (or rather how little) current do we need to light an LED? Exper...

1-07-2012 | An LC oscillator is usually adjusted using a variable capacitor. However, for frequencies below around 100 kHz this calls for a variable cap...

1-07-2012 | What must be the simplest possible radiation meter consists of just a BF245 JFET and an ohmmeter.

1-07-2012 | The author found that a long-neglected gel battery in a hand-held vacuum cleaner had gone high-resistance. It took some effort to make it us...

1-07-2012 | Taking apart a solar-powered lamp revealed a single-transistor voltage converter circuit that allowed an LED to be driven from a 1.2-V cell....