Practice code oscillator (CB21696E)

In the figure we have an astable multivibrator driving a speaker to produce audio signals for Morse code practice.

AC SCR Fast Switch (CB13898E)
This circuit switches a load in 0.013 ms after closing the switch and after the start of each...
Continuity Test (CB22130E)
This circuit can be powered by 2 or 3 small batteries. The resistor can have values between 220...
Dynamic Load (CB1499E)
The purpose of this circuit is to test power supplies functioning as a variable load that can...