I was using a test board I designed to measure component level radiated emissions. During the measurements I started to suspect that some of the emissions were coming from the test board. The only ...

Field tests in Nepal suggest that people who live in areas with arsenic-tainted aquifers may be able to purify their drinking water by passing it through a low-cost, low-tech filter with a simple ...

Simple cellulose filter thoroughly purifies syringe-injected water By Ben Coxworth January 24, 2024 The prototype filter – dirty water in, clean water out The University of Texas at Austin View 2 ...

Figure 1 shows how a Sallen-Key high pass filter (HPF), can be switched on/off using only one extra transistor and resistor. Figure 1 A Sallen-Key HPF filter topology that can be switched on/off using ...