Grounded resistor tunes oscillator: 05/29/03  EDN-Design Ideas / To vary the frequency of any sine-wave oscillator, you should use a pair of ganged variable resistors, and you should thoroughly match their characteristics over the entire variation range to satisfy the oscillator`s balancing conditions. This restriction leads to problems in the tuning range and high cost, thereby limiting the range of applications....

Optimize linear sensor resolution: 03/07/2002  EDN - Design Ideas / A wide variety of sensors and transducers of physical phenomena work via the mechanism of variable resistance. These devices sense temperature, light, pressure, humidity, conductivity, and force, for example. Such sensors measure the physical parameter of interest by reading out the inherent parameter-sensitive resistance or conductance.

Resistance tester: