This circuit compensates for the brightness of an LED as a function of temperature. We found it in an Electronic Design from the 80s. The components admit equivalents.
We found this circuit in the Linear Applications Handbook published by National Semiconductor in...
In a September 1992 Radio Electronics article, we found this basic 555 circuit used to generate fixed...
In the figure we have a simple way to have a peak bargraph indicator. The amplifier is of the...