Open Circuits – Open Source Electronics

Open Circuits is a wiki for sharing open source electronics knowledge, schematics, board layouts, ports and parts libraries. This include open hardware Music Players, atomic microscopes, PC, PDA and mobile phones, and batteries. Please help us to build this resource by submitting your component descriptions, projects, techniques, and PCB footprints.

Open Circuits – Open Source Electronics

Some Projects that look Interesting are

  • Multi-purpose Embedded System
  • dsPIC33 Development Board
  • ADuC832 Development Board
  • N8VEM Home Brew Computing Project

The Open Source Movement, typically covers Open Hardware, Open Firmware, and Open Software. The Open Firmware movement provides firmware which you may also know as soft-IP or FPGA coding see Open Cores for more details.

Excellent examples of Open Hardware projects range from projects at OpenCircuits to Tiny Embedded Ethernet Devices and Advanced & Intelligent Camera Designs which provide solid-state camera and FPGA assisted hardware designs. A solid overview of projects can also be found at Open Innovation Projects.

Interface ICL7135 Voltmeter to Atmel 89C52 or PC

This circuit is an interface between 89C52 of Atmel with 7135 of Intersil. With This circuit you can read analog data of both polarities you can change the range scale with extra circuits, you can store data on a EEPROM or send them to PC thru RS232 or Comm port.

ICL7135 to Printer port Interface

The four Digit Drive outputs and four BCD outputs of the Multiplexed Display Driver of 7135, along with A-D status output which is also four, are routed to four input pins on printer port via three 74HCT373 Digital Switches. This is because we have less Input pins on Port and 4 are shared by making one 74HCT373 transparent and others High Impedance when PC takes a reading. So the three sets of four outputs of 7135 can be read sequentially.

74HCT139 U9A which is controlled by the PC program can select U3, U4 or U5 for sending data to 4 pins on printer port. Data sent on the eight output pins of printer port can be latched by U10B into U6. This eight outputs of U6 can drive relays or lamps.

See also – Milli Volt Source for Printer Port.

Serial Interface a 80C31 to ICL7135

uC Input and Output I/O is Keyboard and LCD when you build a Calculator or a Text/Morse Communicator. When you control a motor it is Drive/Speed and Direction for Motor and Tacho or Opto Counters for Feedback. In both cases you have Input and Output which is Logic or Analog which has to reach the CPU.

Getting the analog into the uC is done here with ICL7135, with a simple two wire serial interface. Here a Pair of CD4538 MMV is used to shape the pulse just right for uC data transfer,…

AT89C52 Parallel Interface to ICL7135

This circuit is an interface between 89C52 of Atmel with 7135 of Intersil. With This circuit you can read analog data of both polarities you can change the range scale with extra circuits, you can store data on a EEPROM or send them to PC thru RS232 or Comm port.

SWTPC Computer Documentation Repository

SWTPC Computer Documentation Repository Radio Electronics June 1949, Guitar Preamp

This site’s purpose is to address the lack of technical information for some of the rarer vintage computers and related peripherals, with a strong focus on SWTPC.

More than 600 pages of assembly instructions, schematics, program listings, catalogs, photos and much, much more!

  • Bill’s Knowledge Base
  • Popular Electronics
  • Radio-Electronics
  • Hands-on Electronics

Circuits using only discrete devices

Here are circuits made of Resistors, Capacitors and Inductors which are passive components. Crystals, Thermistors, Varistors, Variable Passive RLC are also Passive Parts.

Circuits using only discrete devices

Zeners, Diodes, NPN-PNP Transistors, FET, MOSFET, SCR, Triacs are all discrete active devices. ICs and Hybrid Modules are made of many discrete and passive components. In the Integrated Circuits or ASICs, all parts even passives are derived on the Silicon Wafer. In Hybrid Modules the construction uses SMD or Tiny Chip components interconnected in a small ceramic PCB and Hermetically Sealed if needed.

Parts or Components in Electronics

Parts like Switches, Connectors, Relays and PCBs are ElectroMechanical parts. Nuts, Bolts, Screws, Cabinets and enclosures are Mechanical parts.

For a Systems Integrator or Control Panel Designer, the Timers, Controllers, PLC which are Electronic Products become Components or Modules along with Contacters, Current Transformers, AC-DC Drives etc.

Power Electronics and Mains Power

I have updated some pages, and integrated new pages with some explanations. These are related to mains power and power electronics. – ananth

Tables related to Power Electronics

Mains Voltage and Power Circuits

Discrete devices – circuits