Can a microcontroller be used as a relay?
Or, USB to a microcontroller (via a USB-UART bridge if necessary), and drive a relay off that. Connecting an Arduino and using its GPIOs would be cleaner. Another simpler possibility is to use a simple serial port and activate/deactivate one of the signals (DTR for example) with a simple program.
How to trigger alarm with relay from PC sound output?
The background is the following: a Mac-mini collects, by means of different computer programs, alarms from different sources. in order to make the sound signal loud enough, a simple possibility would be to plug a hifi-system on the sound output of the PC, and set the volume to its maximum.
What are the products of the protection relays guide?
[Protection Relays Guide ]System Products [Protection Relays Guide ]Overcurrent Protections6 MiCOM P122 / MiCOM P123
The connection between a microcontroller and a relay must never be made directly. Microcontroller interfacing circuits are used for this purpose. A driver circuit should be used between them. WHY?? There are two main reasons for it:
How are electromechanical relays used in a circuit?
The electromechanical relays, as the name suggests, are powered electrically whereas their operation is mechanical. They are used as switches for the isolation of circuits or fault detection in transmission lines and for many other purposes. A high powered circuit can also be controlled by them by providing a low power signal.
When does the transistor turn off the relay turns on?
When a logic 0 is given to the port pin of transistor then the relay turns off and when a logic 1 is given to it, the relay turns on. A diode 1N4007 is connected to protect the components against the back emf. This back emf is generated in the coil of the relay when the transistor turns off.
How is a magnetic field generated in a relay?
A magnetic field is generated as soon as the current passes through the coil. The armature is activated by this magnetic field which moves the contacts and opens or closes a connection. The diagram illustrates the different parts in a relay and how a relay is operated. On the left side of the figure, a relay is shown in an ‘off’ state.