Circuits & Schematics - 10

Whenever I find myself harboring a constantly nagging thought, I know I will eventually have to get busy and find a way to put it to rest. When I read EDN’s Design Ideas, I look for the range of frequencies over which the circuit will ...

Low-frequency filters, particularly at audio frequencies, usually take the form of active filters. These filters eliminate expensive inductors with windings of many turns. Both analog and digital active filters are most compatible with large-scale ...

The accurate, high-side, current-sense circuit in Figure 1 does not use a dedicated, isolated supply voltage, as some schemes do. Only the selected transistors limit the common-mode range. The circuit measures the voltage across a small ...

Figure 1, fast rise time pulse generator, switches a high grade, commercially produced tunnel diode mount to produce a 20 ps rise time pulse. O1’s clocking (trace A, Figure 2) causes Q1’s collector (trace B) to switch the capacitively ...

Rail-to-rail input and output (RRIO) op amps, both FET and BJT, have been around for a long time, but the possibilities they provide for versatile waveshape generation with simple circuits can still surprise. Figure 1 is an example, outputting a ...

You can use a photoelectric FET as a variable resistor or a potentiometer in combination with a fixed resistor. The H11F3M photoelectric FET has an isolation voltage of 7.5 kV, enabling you to safely control high-voltage circuit parameters. The ...

Magnetic field strength verifier A simple way of producing a large magnetic field strength is to use a solenoid. The field strength and inductance can be calculated accurately from the physical dimensions and the current. The measured value of the ...

This project will explain how to develop a system to measure magnetic field emissions at frequencies up to 150 kHz from high-current power cables without cutting or disturbing the cable. Magnetic fields are present almost everywhere. However, ...

Powering portable telemetry systems for long-term monitoring presents interesting design challenges. Batteries are unsuitable for certain critical applications, and, in these circumstances, designers typically use wireless inductive links to ...

Many applications require a sinusoidal reference voltage synchronized to the ac line voltage. You cannot derive such a reference voltage directly from the ac line because the waveform of the ac line is distorted because of nonlinear loads connected ...