This circuit generates control signals for stepper motors. We found it in a 90s Popular Electronics. The power can be made with a 5 V supply so that it works as a shield.
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...
This circuit can act as a shield being controlled by a microcontroller by pin 1 or 2. The...
This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals...