How fast and how cheaply can test equipment be made? Two can be made for less than 5 dollars, an hour of time and a glass of wine with my sweetheart. A great Wednesday night.
“Real parts” like a battery holder, mini buzzer and alligator clips along with wire with some solder can be had from the local Radio Shack, but that is way more expensive. Biggest tip, keep the circuit under 3 Volts. For testing sensitive circuits, it will be time to uplevel.