Not long after I began contributing to Hagerty eight years ago, I wrote a detailed four-part piece on electrical relays and ...

Pin PA1 of the digital device controls a relay, which switches an appliance on and off . NPN transistor Q 3 activates the relay coil when the I/O line is in the high state. Status LED D 1 connects in ...

If both relays areopen, the motor is off. For electromechanicalrelays, you can use the drivercircuit in Figure 1. Setting the microcontrollerpin to logic one causes Q 1 toturn on relay REL 1, and the ...

[Glitch] got his hands on a slew of relays which are meant for use in industrial equipment. They are designed to operate at 24V. He wanted to use these with common microcontrollers and instead of b… ...