Free Circuit Diagram

RCV420 is a special function integrated circuit chip for 4-20mA current loop receiver. RCV420 provide complete 4-20mA to 0-5V conversion, with 0.1% overall accuracy, 86dB CMR, and ±40V common-mode input range. This IC chip is suitable for many applications:

PROCESS CONTROL
INDUSTRIAL CONTROL
FACTORY AUTOMATION
DATA ACQUISITION
SCADA
RTUs
ESD
MACHINE MONITORING

Here is the schematic diagram of the basic 4-20mA current loop receiver [...]

AN6884 is a logarithmic scale LED bar display driver. AN6884 accept wide range of supply voltage, ranging from 3.5V to 16V. This VU (voltage unit) bar display circuit provides only 5 levels,  but will accept wide range of input level because the scale is logarithmic: -10, -5, 0, 3, and 6dB points. The output current [...]

Using this circuit, you can measure the actual output power of your amplifier.  You can put this circuit in a box as a measurement instrument, or you can integrate it inside your power amplifier to get real power display. The circuit’s schematic diagram is shown in the figure below.

This  circuit would be a handy instrument [...]

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 [...]

If you have to provide a fan to cool your audio power amplifier final transistor, it better to turn it off when it’s not needed. This solution is good since you don’t have to hear the fan noise when you play the music with low level volume at night, the power transistor won’t get hot. [...]