Found on an 80's Elektor, this circuit uses common components, being the diode a general purpose germanium. The coils select the frequency range of the indicator that reaches 60 MHz.
Found in 1969 RCA documentation, this dimmer uses a dual time constant setting to achieve better...
Found in a 1968 Mullard manual, this circuit can function as an infrared audio link. The...
This circuit trips when the input voltage exceeds 30 V. Its base is a DIAC and it can be used to...