A self-heated Darlington transistor pair makes a simple, sensitive, and sturdy airflow sensor. But first an annoying non-linearity needs unbending. If you take a self-heated transistor in a TO-92 package and force it to hold a constant temperature ...
Converting frequency signals to loop current signals creates an economical result for process industry applications. Process industry applications commonly employ multiple motors. Their speeds are monitored by tachometers using magnetic pickups ...
A linearized output is a useful elaboration of a capacitive sensor design. But what if the circuit is located a significant distance from the control electronics? Recently, Design Ideas included a circuit ( Ref. 1 ) that comprised a simple analog ...
An only slightly less simple followup circuit also ratios sensor capacitance to a reference capacitor to measure micrometers this time linearly. A few weeks ago, Design Ideas published a simple circuit of mine that provides an analog interface to ...
This Design Idea describes a versatile test circuit for zener diodes after yet another misread zener diode had infiltrated the ranks of 1N4148 diodes assembled on a pc board. As a bonus, the circuit can serve as a moderate-voltage, power-limited ...
Simple circuit ratios sensor capacitance to reference capacitor to measure micrometers. It’s hard to imagine a simpler electromechanical sensor than the capacitance type, consisting of little more than two plates (or even just one if the ...
Simple to build, but serious instrument for monitoring and predicting weather disasters Lightning detectors are devices designed to detect the presence of lightning strikes. These detectors utilize various technologies to sense the electromagnetic ...
Ground-referenced loads are common in industry. This circuit implements current loop conversions for them. Recently, there have been several published Design Ideas on converting 0/20 mA to 4/20 mA current and 4/20 mA to 0/20 mA current as ...
It’s always gratifying when a simple and successful design idea luckily turns out to have additional applications that you didn’t originally envision. Here’s an example. A while back, the design shown in Figure 1 was accepted for ...
Ordinary bipolar junction transistors can sometimes be precision sensors. When you think of precision components, you usually don’t (and probably shouldn’t) think of general-purpose bipolar junction transistors. Are GP BJTs cheap and ...