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 can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
This stethoscope or amplifier for hearing aid using a crystal headset and microphone was found in a...
The normal use of a 4520 as a divide-by-16 counter is shown in Figure bellow. In the normal...