SEE a simple salinometer or salinity tester in food and water. Good for health. Using LM324 and few parts and LED display easily use, with 9V batts
It is a modern circuit, Thus you can buy all components in the local store or buy KIT. And the important thing is the overcurrent protection.
If you want build hi-fi power amplifier about 30watt to 50Watt or 75 watt. Recommend use TDA2050 below, builds by the integrated circuit and PCB layout.[...]
Have ever you see SCR? Some may it instead of switches and relays. We have seen it works high speed and quiet. Sound good, doesn't it? If we are going…
Do you want low-frequency class B power amplifier? See TDA2020 may be one of choice that you not should miss. Gives 20W to 80W with helping from a transistor.
See 3 ideas of 555 DC polarity probe tester circuit. Check Car Electrical in easy, find open circuit, automotive short circuit, loose connection. Learn more
Reduce 12V battery to 6V for small circuit. You will love it same us.