This circuit was found in a 80's Popular Electronics. The sensor can be any phototransistor. The circuit is indicated for an audio link modulated in pulses.
This musical doorbell was found in a Popular Electronics from the 90s. The U4 melody generator...
This circuit was found in a 2005 Linear Technology application manual. The circuit is based on the...
This oscillator produces a signal with a central frequency in 1 MHz. This frequency can be...