Tuesday, April 22, 2014



The MOC303XM and MOC304XM devices consist of a AlGaAs infrared emitting diode optically coupled to a monolithic silicon detector performing the function of a zero voltage crossing bilateral triac driver. MOC3041.

They are designed for use with a triac in the interface of logic systems to equipment powered from 115 VAC lines such as teletypewriters, CTRs, solid-state relays, industrial controls, printers, motors, solenoids and consumer appliances, etc.
  • Simplifies logic control of 115 VAC power
  • Zero voltage crossing
  • dv/dt of 2000 V/µs typical, 1000 V/µs guaranteed
Motorola used to make these then it was Infineon Technologies now Isocom also makes it

MOC3041 Zero Crossing Triac Output, 6 Pin

See the original Motorola Application below.

MOC3041 Zero Crossing Triac Output, 6 Pin

Ananth -

These were used by me to make solid state relays. Look at the circuits here Power Electronics Circuits. The were used to control Heaters from DC control signal from a Proportional Temperature Controller. The Magnetic Contactors can be avoided for lower powers. At higher powers SCR banks become a bit expensive.

The SSR has no mechanical wear and tear but heat up at high currents. So if we overrate by 5 Times then it is an excellent solution for lower power controls upto 5 Kilo Watts. The cycle time of Contactors must be 20-60 Seconds to make it last long. In a SSR a one second cycle time is possible as 10-20mS is the switching speed due to zero crossing.

Sunday, April 13, 2014

Multisim from National Instruments

An industry-standard SPICE simulation environment from NI. An excellent yet easy to use tool for students and new design engineers too. It helps you in the design process, creating your first prototype and PCB.

Multisim from National Instruments

Learning and Testing circuits by simulation and checking out the best fit for your PCB.Getting your projects done right the first time without many trials.

Multisim from National Instruments

This application notes introduces different applications that include various semiconductor devices, simulated and validated in Multisim

Introduction to Simulation and Analysis of Semiconductor Applications

Features Include

Enhance Simulation with 26,000+ Accurate Devices Devices from Maxim, Infineon, NXP, ON Semiconductor, and Analog Devices add to the library of the latest SPICE models to evaluate design choices.

Complete Senior Design Projects With NI myRIO Support Use preconfigured NI myRIO NI miniSystem templates and LabVIEW co-simulation to develop advanced controls, robotics, and measurement projects.

Learn Digital Logic With Digilent FPGA Board Support Export digital logic schematics from Multisim in raw VHDL format to target a suite of FPGA digital teaching platforms.

Tuesday, April 01, 2014

Using Linux in Embedded Electronic Devices

Embedded Linux is not only Open Source, but can be adapted to any type of dedicated embedded system. It is more like a configurable firmware for Embedded Equipment. Its ability to manage multiple tasks efficiently makes it more friendly and stable, compared to any other OS.

When you look at the History of Operating Systems, you will see that that an OS that meant serious business was UNIX. It was the anvil for the creation of the C Language and AWK. Now we have Linux, the evolved Unix like OS, which is comfortable and versatile for Networking and Clustering.

Related Reading
Here is a Embedded Linux Wiki for the embedded product design community.

Gadgets and Appliances are become increasingly complex. More memory and CPU power for small devices are commonplace. Linux is one OS that can be muntzed to the smallest size. This helps developers make something like a super-firmware. Just what you need for that device, can be the OS.

Touchscreens for Home Appliances, wireless networking and web enabled consumer electronics make Linux an excellent escalation from "Firmware". For tiny systems a firmware is the OS. For complex devices today, Linux is user configured firmware.

Leopardboard DM355

Leopardboard DM355
  • High-performance Digital Media System on Chip 
  • ARM926EJ-S core 
  • Video Processing Subsystem (VPSS) 
DM355 combines high performance MPEG4 HD (720p) codecs and JPEG codecs up to 50M pixels per second, high quality, and low power consumption at a very low price point.

Seamless interface to most additional external devices required for a complete digital camera implementation.