As part of a long-term project to hack an electric sewing machine, Barbara "PC-Monster" W has been experimenting with an optotriac to allow isolated control of the mains current to the motor via a microcontroller, in this case an Arduino. An optotriac is similar to an optocoupler except it can handle mains-rated voltages - so if using one take care and have qualified people with you.
Moving forward Barbara hopes to detect the position of the sewing needle, motor speed and control the speed for some Arduino-controlled automation, so to keep track visit her blog here. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you're interested in switching high-current loads from an Arduino or other development platform, check out our NDRIVE: N-MOSFET driver output module:
This high-power N-MOSFET module lets you switch high-current loads using a tiny microcontroller. Perfect for controlling that set of traffic lights mounted in your living room! Works brilliantly for automotive projects such as switching high-power 12V lights and high wattage LEDs. It can be driven directly from a 5V logic output, and handles up to 60V at 20A. For more information and to order, click here.