Circuits & Schematics

The circuit in Figure 1 adds a soft muting switch with power-up/power-down muting to a line-level audio circuit. R 4 , C 1 , and JFET Q 1 quietly ground a signal in 100 to 200 msec when you close S 1 or release it when you open S 1 . Potentiometer ...

When talking about standalone single cell battery chargers only one popular name came into my mind that is our versatile Li-Ion/Li-Po TP4056 battery charger. Which is vastly available and has a lot of features related to battery protection. The ...

The typical regulator output network Many voltage regulator chips, both linear and switching, use the same basic two-resistor network for output voltage programming. Figure 1 illustrates this feature in a typical switching (buck type) regulator, ...

Semiconductor laser diodes (SLDs) are often packaged with a photodiode. The output current from this photodiode can be monitored to regulate the output power intensity of the laser diode. SLDs, however, are prone to pathological drifts, such as ...

The TL431 has been around for nearly 50 years. During those decades, while primarily marketed as a precision adjustable shunt regulator, this legacy device also found its way into alternative applications. These include voltage comparators, audio ...

One classic set you’ll see in most гvintage mystery movies is an interrogation room with a “two-way” mirror in one wall. This cool gadget lets the witnesses see the suspects from another room while the suspects can see only ...

Frequent contributor Nick Cornford recently shared design ideas incorporating cool circuits for linear-in-pitch voltage-controlled oscillators (LPVCOs): Revealing the infrasonic underworld cheaply: Part 1 ( Ref. 1 ) and Part 2 ( Ref. 2 ) A ...

A recent Design Idea, “Three discretes suffice to interface PWM to switching regulators”( Reference 1 ), demonstrated one way to use PWM to control the output of a typical switching voltage regulator. There were some discussions in the ...

In Part 1 of this Design Idea [ 1 ], we saw how a standard electret microphone capsule can be persuaded to detect infrasonic signals down to a fraction of a Hertz by adding some fairly simple equalization. In this second and concluding part, we ...

Electrets aren’t only used as audio pickups. For decades, they have been employed in security systems to detect unexpected changes of air pressure within rooms, while more recently they can be found in vapes as suck-sensors (or, more ...