This circuit was found in a 90s Wels' Think Tank. The frequency depends on C2 and R3. The handset or speaker must be at least 80-ohm. Observe the low supply voltage.
The circuit shown in figure 1 is a suggested application for ISL8107, a new integrated circuit from...
Lumileds LUXEON Infrared LEDs can be purchased from Mouser Electronics in a wide selection of...
This small audio amplifier circuit in complementary symmetry was found in the 1974 Mullard...