Circuits & Schematics

A short while back, I published a design idea ( Ref. 1 ) that uses a single linear pot to control the gain of a high performance OP37 decompensated op-amp over an unusually wide ( 30 dB to +60 dB) range. Figure 1 shows the circuit. Figure 1. ...

You can use the simple sensor circuit in Figure 1 to remotely monitor the level of liquid water in a vessel such as a swimming pool. The LMC555 sensor oscillator provides an output-signal frequency that is a function of the water level. This signal ...

The 0- to 20-mA current loop is a reliable means of data communication in industrial applications. These circuits use a precision shunt in the receiver to convert the current signal into a voltage signal. Accidentally connecting the precision ...

Pulse width modulation (PWM) is a terrific basis for digital to analog conversion. Credit goes to features like simplicity and (theoretically) perfect differential and integral linearity. Unfortunately, PWM’s need for ripple filtering tends ...

One option for driving high-brightness LEDs uses the standard stepdown buck converter (Figure 1). The sense resistor, R S , generates a feedback voltage, V FB , that sets the desired LED current, I LED , according to the equation Figure 1. A ...

Battery stack voltage monitor development ( Reference 1 ) is aided by a floating, variable potential battery simulator. This capability permits monitor accuracy verification over a wide range of battery voltage. The floating battery simulator is ...

The fuse described in this design idea does not drop the connection, it simply limits the output current. A behavior that is similar to a polyfuse, however the circuit shown in Figure 1 is more accurate, does not depend on ambient temperature ...

There are many applications where an ADC needs to process a small differential input signal in the presence of a large common-mode signal. Traditional instrumentation amplifiers (in-amps) are not commonly used in these applications, due to their ...

A silly simple and ubiquitous circuit network is a variable resistance consisting of the series connection of a manually adjusted rheostat-connected pot and fixed resistor shown in Figure 1. Figure 1. Classic variable resistance with the series ...

Despite the title, this DI does not describe a gadget to tell you when to don your shades, but instead features a useful add-on to (analog) audio kit. Built into a mixer, for example, it will show when the output of any stage is approaching ...