Ameba Transmitter (CB21873E)

We found this small FM transmitter in an Australian publication from 1991. The 3-transistor circuit has a range on the order of 400 meters.

| Clique na imagem para ampliar |

2 to 9 kHz PLL Synthesizer (CB4566E)
We found this circuit at Modern Electronics in January 1991. The magazine no longer exists, but...
Bidirectional switch (CB9162E)
Found in a 90's EDN, this circuit can be used as a shield. The components depend on the MOSFETs...
Cooking Timer (CB18596E)
This circuit will trigger an audible warning signal after the end of the pre-programmed timing. Using...