This circuit works on analog I/O ports and was suggested by an Electronic Design from the 90s. It can be used to work as a shield in projects with microcontrollers.
This circuit uses only passive components calculated for the desired frequency. We found it in an...
This fourth-order circuit was found on an 80's Radio Electronics. The power supply must be...
This simple circuit controls the brightness of an LED from LDRs, NTCs, PTCs or other resistive sensors....