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 ...
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 ...
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 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 ...
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 ...
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 ...