: Relays can be triggered by standard 5V or 3.3V digital signals, and some models include visual LED indicators to show when a channel is active.
// Sequence 3: All relays OFF for (int i = 0; i < 4; i++) digitalWrite(relayPins[i], HIGH);
Since Proteus (versions 8.6 through 8.16) does not always include a pre-made, integrated "4-Channel Relay Module" component in the default library (it usually only provides single relays), most users rely on a schematic design or a custom library file to simulate it.
