This is the receiver for the previous transmitter. The signal consists of digital pulses with a compatible TTL or CMOS output. The integrated circuit is a 4093 and a photodiode of any type.
This circuit is from a Radio Electronics magazine from December 1971. The resistors are power...
This general purpose circuit was found in a Popular Electronics. It is intended for detecting the...
This circuit produces a tone by a small loudspeaker. Frequency depends on C1 and C2. These...