Circuits & Schematics

In April 2012, EDN published a circuit by John Fattaruso ( Ref. 1 ) that lets you quickly measure the drain-source saturation current and the pinch-off voltage of both an N-JFET and a P-JFET. The pinch-off voltage (V P ) is measured by inserting a ...

Figure 1’s circuit is not as fast as some other circuits, but its 2.5 MHz output settles from a full-scale input step in only 3 us. This makes the circuit a good candidate for FM applications or any area where fast response to input movement ...

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 ...

If you have a load with a variable or poorly specified resistance and want to regulate the power applied to it (a heater for example), merely controlling the voltage or current will not work, as in both cases the power P = I 2 R = V 2 /R depends on ...

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 ...

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, ...

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 ...

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 ...

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 ...

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 ...