This circuit is from the Motorola Linear Databook of 1990. The coils must be according to the frequency of the signal.
This circuit uses the flip-flops from the previous circuit to implement a 3-digit binary counter. The...
The voltage comparator used in this application is the NCX2220 from NXP. What this circuit does is...
The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from...