Found in American documentation from the 90s, this circuit can be used as a shield with the replacement of the output optical coupler. The operational also admits equivalent.
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....