Relays are bidirectional devices.
Its not, a diode is unidirectional.
Bidirestional
Data flow is always bidirectional my friend, don't confuse.
A unidirectional amplifier & a Bidirectional amplifier
Unidirectional TVS: A TVS device with asymmetrical current versus voltage (I−V) properties. A unidirectional TVS is best suited for protecting circuit nodes whose signals are unidirectional or always above or below the reference voltage, usually ground. Bidirectional TVS: A TVS device with symmetrical I−V properties. A bidirectional TVS is best suited for protecting electrical nodes whose signals are bidirectional or can have voltage levels both above and below the reference voltage, usually ground
Bidirectional sampling gates allow signals to pass in both directions, enabling two-way communication, while unidirectional sampling gates permit signal flow in only one direction. This fundamental difference affects their applications; bidirectional gates are often used in scenarios requiring feedback or two-channel systems, whereas unidirectional gates are typically employed in simpler, one-way transmission systems. Additionally, bidirectional gates may introduce more complexity in design and control compared to their unidirectional counterparts.
The optical fiber can be used both as unidirectional and bidirectional. The main application of optical fiber is in long-distance links, so there exists no need to employ them as unidirectional. For each direction different wavelengths are used to modulat the signals. At the same time many bidirectional signals can travel through the same optical fiber.
1) IrDA devices have built-in error checking; remote controls usually do not have this feature. 2) Remote controls work at greater distances. 3) Remote controls are unidirectional, but IrDA devices are bidirectional.
The arc is the line that connects two nodes in a network. There are two kinds of arcs; unidirectional and bidirectional. Unidirectional means the flow is in one direction (if you are studying for example the water supply system in a city). Bidirectional means the flow is in both directions. Network models are very helpful to simplify real problems.
Silicon Controlled Rectifiers (SCRs) cannot be used as bidirectional switches because they are designed to conduct current in only one direction. When forward-biased, an SCR can be triggered into conduction, but it cannot be turned off by simply reversing the voltage; it requires the current to drop below a certain threshold. This unidirectional characteristic limits their application in circuits where bidirectional current flow is needed, such as in AC applications. For such purposes, devices like TRIACs or bidirectional thyristors are more suitable.
The control bus is a unidirectional bus because it can receive the data from any kind of inputs and send back the output. This whole process is done by the data buses.
There are two types of dot matrix printer 1. unidirectional 2. bi-directional