Zero-Crossing Triac Driver – MOC3041

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

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.

ICL7107 DPM and DVM chip from Intersil

ICL7107 DPM and DVM chip from Intersil

The Intersil ICL7106 and ICL7107 are high performance, low power, 31/2 digit A/D converters. Included are seven segment decoders, display drivers, a reference, and a clock. The ICL7106 is designed to interface with a liquid crystal display (LCD) and includes a multiplexed backplane drive; the ICL7107 will directly drive an instrument size light emitting diode (LED) display.

3-1/2 digital display for +/- 199.9mV

DPM ICL7107 Digital Panel Meter

  • Guaranteed Zero Reading for 0V Input on All Scales
  • True Polarity at Zero for Precise Null Detection
  • 1pA Typical Input Current
  • True Differential Input and Reference, Direct Display Drive
  • LCD ICL7106, LED lCL7107
  • Low Power Dissipation – Typically Less Than 10mW

Ananth –

3-1/2 Digit DPM ICL7107 Digital Panel Meter

This is one of the first mixed CMOS IC, I used it after studying Intersil CMOS Hot Ideas Book. It is also the most widely used Display chip. Many Millions of Instruments are built using this chip both in Instrumentation and Industrial Automation. The ICL7106 was most popular in Hand Held DMM’s and Clamp Meters as it used to drive a LCD Display. ICL7109 was to interface with Digital Comparators and Microprocessors

ICL7109 12-Bit A/D Converter with 3-State Binary Outputs