Electronic Design

Isolated Circuit Digitally Indicates 120-/220-V Line Voltage (.PDF Download)

For applications such as motor control or power supplies, it’s often necessary to know whether the ac line is at 120 V or 220 V to adjust the operation. The circuit illustrated in the figure monitors the ac line and provides a basic output indicating whether it is at 120 V or 220 V, with the output at the transistor collector going low for 120-V and high for 220-V inputs...

Register to view the full article

By registering on Electronic Design now, you'll not only gain access to premium content, you'll also become part of an exclusive, robust global engineering community!
Participate in Expert and Reader driven Q&A's
Start your own conversation by commenting on any article or blog
Download high-quality content including the highly anticipated Salary & Career Report