This 1.5W tube amplifier was found in an American documentation from 1947. It is a direct rectification circuit without the need for a power transformer.
In this phase shift circuit, the transistor can be any general-purpose transistor. The circuit is from...
This low-power intercom can be powered by solar cells. The circuit is two-way, with an integrated of the...
The resistors R1 and R2 consist of 8 220 ohms x 2 W resistors connected in parallel. The...