This circuit was found in RCA documentation from the 1980s. The circuit uses LDRs of the time and the 50 uA instrument has zero in the center. R1 and R2 may have 2k2 and R3 10k typically.
This circuit was found in a Poptronics of the 90's. The circuit limits the load current to 0.6 A....
This simple circuit can use general purpose transistors and SCRs like the TIC106. The warning...
This circuit is from a 90s 73 Amateur Radio Today. The circuit uses a MOSFET to provide 10 W of...