This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The maximum current is 170 mA. and the integrated circuit is the MAX655 from Maxim.
In this phase shift circuit, the transistor can be any general-purpose transistor. The circuit is from...
This circuit is from an old Mullard (Philips) manual with applications using the 555. Choosing...
This simple TTL digital amplifier uses NAND gates and a high impedance speaker. ...