This simple circuit generates a good and stable 1V peak-to-peak square wave at 100Hz, 1KHz and 10KHz using a single 1.5V cell as power supply. An useful feature of this circuit is that frequency changes can be obtained by switching only one capacitor at a time. Current consumption is about 600ľA. * If a precise 50% duty-cycle is needed, trim R1 and monitor the output wave form by means of an oscilloscope. * A good 500mV peak-to-peak square wave is provided even at 1V supply.

Build your own LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and "Zero Out" function to make sure the readings are as accurate as possible ... [more]