This sound effect circuit is from a Radio Electronics magazine from December 1969. The transistors support equivalents and the power is provided by a battery to reduce the possibility of noise.
We found this circuit in a Popular Electronics from the 80s. The circuit is based on the LM3909, a low...
In the figure we have the basic configuration of an operational amplifier for AC signals using the...
This timer, like the previous circuits, uses a currently uncommon integrated circuit. The time is...