Схемы

Stephen Woodward

Generating analog sawtooth waveforms (linear ramp followed by a quick reset to zero) from digital timing signals is a common function. It usually requires a negative supply as sketched in Figure 1, where Negative current through R1 ramps up ...

Jayapal Ramalingam

Figure 1 gives a simple circuit for the PUSH ON, PUSH OFF function with only a few inexpensive components. In this design, the output is connected to the input of the gadget when you press the push button (PB) once. For the next push, the output is ...

Stephen Woodward

The LM4041 has been around for over 20 years. During those decades, while primarily marketed as a precision adjustable shunt regulator, this classic device also found its way into alternative applications. These include voltage comparators, ...

Peter Demchenko

Almost every wall power supply has no indicator showing whether current is consumed by the load or not. It seems that this was a shortcoming that was not only noticed by me: I once saw the solution given in Figure 1. Figure 1. Wall power supply ...

Mark Shill

When probing digital logic levels on a circuit board, locating the indicator of the logic level near the probe tip is convenient, so that you can keep both the indicator and probe tip constantly in sight. When using a handheld DVM or oscilloscope ...

John Betten

Switching power supplies can be notorious noise generators. You should prevent this noise, which is conducted, radiated, or both, from returning to the input source, where it can potentially wreak havoc on other devices operating from the same ...

Stephen Woodward

Figure 1’s negative constant current source has been a textbook application for the LM337 regulator forever (or thereabouts). It precisely maintains a constant output current (I OUT ) by forcing the OUTPUT pin to be the negative V ADJ ...

Stephen Woodward

Tachometry, the measurement of the speed of spin of rotating objects, is a common application. Some of those objects, however, have quirky aspects that make them extra interesting, even scary. One such category includes outdoor noncontact sensing ...

Yongping Xia

A previously published Design Idea describes a practical gadget that has the potential to save a lot with little investment ( Reference 1 ). However, the circuit uses 120 V line voltage and, as such, it is not that convenient for many applications. ...