Up front: some background. The air-temperature sensor attached to my (home-brew) rain gauge became flaky. Short-term solution: fix it (done). Longer-term goal: improve it (read on). That sensor is a standard Vishay NTC (negative temperature ...
Many recent Design Ideas ( Ref, 1 ) have involved button-pushing to control power. Some may have been more resistant to contact-bounce than others but how can we really check that? This DI describes how some simple circuitry can simulate bouncy ...
Precision-matched capacitor pairs are commercially available items, but only in a limited range of values, working voltage, and dielectrics. Plus, sometimes an extra critical application with extra tight tolerances (or an extra tight budget) can ...
I recently published a simple design ( Ref. 1 ) for a platinum resistance detector (PRTD) 4 to 20 mA transmitter circuit, illustrated in Figure 1. Figure 1. The PRTD 4 to 20 mA loop transmitter with constant current PRTD excitation that relies on ...
High accuracy, stability, and wide operating range make platinum RTDs (resistance temperature detectors) popular temperature transducers. Signal conditioning these devices requires care to utilize their desirable characteristics. Figure 1’s ...
Accurate, inexpensive, and mature platinum resistance temperature detectors (PRTDs) with an operating range extending from the cryogenic to the incendiary are a gold (no! platinum! ) standard for temperature measurement. Similarly, the 4 to 20 mA ...
To generate high voltages with proper insulation between the “hot node” and the rest of the circuitry, a car ignition coil can function in place of a high-voltage transformer. These coils have voltage ratings of approximately 20 kV, so ...
Precision-matched resistors, diode pairs, and bridges are generic items. But sometimes an extra critical application with extra tight tolerances (or an extra tight budget) can dictate a little (or a lot) of DIY. Figure 1’s matchmaker circuit ...
Stephen Woodward, a prolific circuit designer with way more than 100 published Design Ideas (DIs), had his “80 MHz VFC with prescaler and preaccumulator” [ 1 ] published on October 17, 2024, as a DI on the EDN website. Upon reading his ...
Implementing a simple digital-to-analog converter (DAC) by cascading a single pulse width modulator (PWM) and an analog low-pass filter is nothing new. Nor is applying to a filter the sum of the outputs of a most significant 2 N -count PWM and a ...