This simple tester was found in a Popular Electronics from the 90s. The circuit is powered by two 9 V batteries since it requires a symmetrical source.
This small source is suitable for low consumption equipment that uses batteries. The circuit is...
This interesting circuit was found in an Argentinean Radio Chassis Television magazine from March...
This circuit is from an 80's documentation, firing when the input voltage exceeds 5 V. The SCR can...