To measure a zener diode’s breakdown voltage, you need a dc voltage source whose voltage exceeds that of the zener voltage...
Circuit lets you measure zener voltages and test LEDs
AC voltage zero cross detector
This project provides AC voltage zero-cross timing detection and a DC voltage after diode rectification with high accuracy. Possible applications for such circuits are AC motor controllers, AC lamp controllers, AC Dimmer Controllers, Home Appliances...
MOSFET shunt regulator substitutes for series regulator
You would normally use a series linear regulator or a dc/dc converter to obtain 3 V dc from a higher supply. However, when breadboarding a concept, you may be able to use a shunt regulator, especially if a series regulator of the correct voltage is unavailable...
Cancel PWM DAC ripple and power supply noise
Several years ago, I published a design idea “Cancel PWM DAC ripple with analog subtraction," showing a simple trick for the cancellation of PWM output ripple. It employs passive summation of the usual PWM signal with its AC-coupled inverse, thus dramatically attenuating the undesired AC component...
Analog peak detector frames mechanical bounce, quantifies contact resistance
Mechanical bounce often occurs while trying to measure current or resistance on experimental materials or from routine switch-contact action. It can be a problem if you are trying to preserve the bounce or noise phenomenon within the measurement system itself...
Shunt circuit clips large transients or regulates voltage
The circuit is a high-power analog of the popular TL431 programmable shunt regulator. This two-terminal circuit is convenient when the drain of the P-channel FET is grounded, since it needs no isolation from a grounded heatsink. There is no mirror analog of the TL431 however...
Improved current monitor delivers proportional-voltage output
This Design Idea expands the capabilities of a previously published one. The original version featured a current transformer whose secondary winding formed part of an oscillator's tank circuit...
Optimize High-Current Sensing Accuracy by Improving Pad Layout of Low-Value Shunt Resistors
Current-sense resistors, which come in a variety of shapes and sizes, are used to measure current in many automotive, power control, and industrial systems. When using very low value resistors, the resistance of the solder becomes a substantial portion of the sense element resistance...
Simple diode serves as a sensor for a thermal probe
This Design Idea describes a two-transistor thermal probe for diagnosing circuit problems, such as hot components and thermal runaway. Although the probe does not provide an accurate temperature measurement, it acts as a quick check for potential thermal problems...
Impedance transformer flags failed fuse
Figure depicts a circuit that detects the opening of a miniature circuit breaker or high-rupture-capability fuse in a high-reliability telecommunications power supply. The circuit generates an alarm when a failure changes the impedance of an electromagnetic sensor...