Aquinas' definition. The Oxford Concise Dictionary of the Christian Church defines acedia (or accidie) as a state of restlessness and inability either to work or to pray. Some see it as the precursor to slothâone of the seven deadly sins.
A train horn is a powerful air horn that serves as an audible warning device on electric and Diesel locomotives. The horn's primary purpose is to alert persons and animals to an oncoming train, especially when approaching a grade crossing. The horn is also used for acknowledging signals given by railroad employees, such as during switching operations.
The horn relay (or any relay) usually acts as a high current switch that can be controlled by a low current signal. The signal in this case, is you pressing the horn button on the steering wheel. The small current signal from the horn button is sent to the relay via a small gauge wire.