Free Circuit Diagram

Autoranging is useful to extend the measurement range of an available ADC (analog-to-digital converter).  Autoranging will best implemented for multiplexed input.  LTC1257 is appropriate for system autoranging, adjusting an ADC’s full-scale range. During the conversion process, U2 and U3 receive the full and zero scale codes, respectively, that correspond to a [...]

This testing instrument provide two alternate fuction: signal injector and signal tracer.  This audio signal tracer/injector is very helpful in trouble shooting audio circuits, when you need to test a circuit by injecting a signal and observe the output (by watching the oscilloscope or by hearing the loudspeaker for example), or by tracing some points [...]

You might be familiar with passive crossover network installed inside your speaker box, consist of inductors and capacitors. The problem with passive crossover network is that they dissipate the audio power, so it’s not environmentally friendly, contributing a little disaster of global warming.  Moreover, the capacitor and the inductor in the passive crossover network contribute [...]

This circuit detect the amplitude of audio signal, suitable for audio level detection that demand for high precision. Amplitude detection or signal envelope detection is usually implemented using a peak detector. An ideal amplitude detector give continuous level at any time because the amplitude of a sine signal (every signal can be seen as sine [...]

This LED (Light Emitiing Diode) display consist of 10 LEDs to indicate the level of an input signal. If the signal is small, only LED#1 will light, and if the signal level getting higher then you’ll se the light dot will move through LED #2, #3, #4, … and so on. When the signal input [...]

The schematic diagram below show a complete barometric pressure signal conditioner that operates from a single 1.5V battery. We can get the best accuracy and stability if we use bonded strain gauge and capacitive-based transducer,  but they are expensive.  This design introduce a new type of semiconductor transducer that achieves 0.01″ Hg (inches of mercury) [...]