This optical theremin was found in a 90s Hands-On Electronics. The basic frequency is given by C1 and the output is made in a speaker through a small output transformer.
This circuit is based on an integrated TIPL62 from Texas Instruments, uncommon today and an...
This circuit appears in other articles and suggestions for circuits in this section from other...
This circuit was obtained from an Electronic Design from the 90's. The circuit generates signals at a...