Why your circuit does not work? Because the battery is run out. These low voltage indicator circuits may helpful for you. If you can know before and change a new one right now. It makes you not have to waste time when using those projects.
Include: Volt meters :: Sound level meter :: Analog vu meter :: Soil moisture meter :: Digital meter circuit diagram :: Temperature measurements :: Electronic measurement tools :: Frequency meters :: Best battery tester :: Transistor tester project
This is Blown Fuse indicator circuit by LED Display. A Fuse be the equipment protects that use often most. Because of cheapness can use protect electronics
This is the Transistor tester circuit into PCB. When your project do not works, the tester electronic parts or component be what need very much.
This is Bicycle distance meter circuit and main parts are reed switch detect to CD4017 then connected to Optocoupler and display to frequency counter. [....]
This is Coaxial cable tester circuit,to check the cables inside and outside. Check the continuity,short-circuited,detect high resistance, By show with LED [...]
This is 555 audio simple ohmmeter circuit. Some times, we need to measure roughly resistances only. we can know resistances by audio also fast check. [...]
Simple capacitance measurement circuit using IC-555, with the frequency counter as digit number display, that can measure the period.To show value directly [...]