Editor’s note: I am pleased to present an interesting discussion from Phil Ebbert, Riedon’s VP of Engineering, regarding resistors and Silicon Valley. As an added bonus, there is a really nice tutorial book offered free in a link below entitled The Ultimate Guide to Resistors .
There is probably nowhere in the world more closely associated with the electronic components industry than California and, most notably, Silicon Valley. However, one concept that underpins the whole industry – that of electrical resistance – was discovered in Munich, Bavaria, which became part of the German Empire in 1871. And, purely by coincidence, Munich is now home to the world’s largest business-to-business electronics trade fair, electronica.
Georg Simon Ohm, a mathematician and physicist, was born in Bavaria on 18th March 1789. He became fascinated by electricity shortly after electromagnetism was discovered in 1820. At the time, current was measured by measuring the magnetic flux around a wire conductor.
Georg Simon Ohm, mathematician and physicist
Ohm noticed that flux levels varied with the type of wire and sought to establish if there was a relationship between voltage, current and the type of material of which the wire was composed. He published his first paper on the subject in 1825 then went on to publish a book, ‘Die galvanishce Kette, mathematisch bearbeirtet’, which describes what we now know as Ohm’s law, in 1827. His theory was initially met with much scepticism but gradually gained acceptance and in 1841 his work was achieved official recognition when he was awarded the Copley media by the Royal Society in 1841. He died on 6th July 1854 and the SI (International System of Scientific Units) unit of electrical resistivity, the Ohm, is named after him.
As every electronics engineer knows, Ohm’s law states that R = V/I where R is electrical resistance, V is applied voltage and I is the current flowing through the resistor. The law holds at a given temperature and is applicable to most, but not all, materials. It’s not actually a mathematical law but an experimental one derived from a substantial body of observed measurements.
By the way, there’s a statue of Georg Simon Ohm in front of the Technical University, Munich. If you’re visiting Electronica, think about dropping by to pay your respects to one of the true pioneers of the industry that we’re part of today.
Of course, Wikipedia provides a great summary of how resistors work and of the types now available but to take a deeper dive into today’s resistor technology and the varied specialist applications for these components, the Ultimate Guide to Resistors is a good starting point.