Free Circuit Diagram

PDF Download Library, you can download datasheet, ebooks, application notes, or other pdf documents. Circuit Diagram, a comprehensive explanation about electronic circuit diagram, electrical diagram, or electronic schematic. EDN Magazine, electronic engineering journal, contain many electronic engineering related articles. Design Idea is one of my favorite column. All About Circuits [...]

This pin diagram will be  useful when viewing these connectors. Sometimes you hold a soldering iron to the back of the connector, and you don’t remember the numbering of the pin. Here is the pin diagram for your reference: The number of each pins are actually  stamped on both sides of any D-type [...]

Many new computers now only has USB port, and this serial to USB adapter might be the only help for old devices that provides only RS232/COM Port. This serial adapter uses FT232 USB-RS232  converter IC from FTDI (Future Technology Devices International).  The main features of this USB serial adapter chip are: 384 [...]

RS485 interface gives some more benefits compared to RS232: simplicity and the robustness for long distance transfer. RS485 is simpler because it uses only two wire (or a single pair) to carry out the data in bidirectional manner, using RS232, we need 3 wires at minimum to carry the data bidirectionally. RS485 cable length can [...]

This circuit is another radio frequency (rf) field strength meter, similar with our previous field strength meter circuit, but with lower supply voltage (only a single cell 1.5V battery). Here is the schematic diagram of this rf strength meter circuit: To use, turn on transmitter and meter; adjust C1 for peak [...]

Notch filter is known as band-cut filter or band-reject filter. The fuction of this filter is to remove some frequency portion of a signal. The schematic diagram of this filter circuit, a second order notch filter is depicted in the figure below. The formula is actually complicated, but by taking the R3=R4 and [...]