Cost-Effective Touch-less Doorbell to Combat COVID-19

In this paper, a novel method to effectively mitigate the spread of COVID-19 at the local level due to contact with any surfaces has been introduced. Our innovation - a device called ‘Touch-less Doorbell’ can well prove to be an essential safety shield for the common public in their fight against this pandemic. This idea of the contactless doorbell will stand out from conventional ones installed in our houses in terms of being durable, energy-efficient and cost-effective. Once an infected person uses the doorbell, the virus holds onto that and spreads accordingly when an uninfected person touches the same. The existing doorbell itself can be reused by integrating some power electronics components without entirely replacing the existing one. Thus, the doorbell can be made to operate in the touchless as well as touch enabled mode. The touch-less doorbell circuitry comprises of an operational amplifier as a voltage comparator, a potentiometer and photodiode along with the relay setting and switching circuit. Hence, the comparator circuit and switching circuit forms the two essential parts; with the comparator circuit comparing the sensor's threshold with reference value and switching circuit (consisting of a transistor) for turning the bell ON. A detailed cost analysis of the proposed model has also been performed concluding it to be a budget friendly option without compromising on the product's quality.