This power step for relay activation was found in the 1964 RCA transistors manual. The circuit is of the NF type and the transistors admit equivalents. R4 depends on the drive voltage.
This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The...
This circuit can be used for signaling a panel with a common incandescent lamp. The lamp will...
This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The...