This circuit was suggested by National Semiconductor and is present elsewhere on this site. The LM2575 is not very common today and should be mounted on a heatsink.
This is the traditional Hartley Oscillator configuration for high frequencies. For 1 MHz wind 80...
This circuit came out in a 1983 English magazine, but it can be easily assembled today, as the...
This circuit was found in a March 1988 Radio Electronics. The voltage scale is set at R3. 19 LEDs...