The circuit shown is from Texas Instruments optoelectronics documentation. The input signal is audio and equivalent LEDs can be used. Other operational amplifiers can also be used.
Found in older documentation this setting applies to modern components, noting that the power...
This circuit can send signals in both the VHF and FMN bands with a range of a few tens of meters. The...
This circuit indicates when the voltage of a 12 V battery is low. With changes, for example, the...