Timer, Counters and Relays
Relays:
A relay is an electrical switch that opens and closes under the control of another electrical circuit. In the original form, the switch is operated by an electromagnet to open or close one or many sets of contacts.
A simple relay has 5 pins. The left 2 pins are the operating part by taking input, the rest of the pins are the switching part to get output. A 4 pin relay doesn’t have NC pin.
When current will flow in the inductor, the switch will be attracted, hence opening the normally closed (NC) switch and closing the normally open (NO) switch.
Timer:
A timer is a specialized type of clock. A timer can be used to control the sequence of an event or process.
The timer switches on, when it is energized for the specified time. If it is interrupted, it starts with 0, i.e. to reset the timer, we’ll have to give an interruption to the energy source being provided.
Counter:
In digital logic and computing, a counter is a device which stores (and sometimes displays) the number of times a particular event or process has occurred, often in relationship to a clock signal. In practice, there are two types of counters:
- up counters, which increase (increment) in value
- down counters, which decrease (decrement) in value