The mosquito-bourne spread of diseases is a challenge humans are facing. To repel the mosquito, various devices are available. Domestically popular are mainly the Allethrin family of Pesticides. Even though the air-bourne potency is 0.1% of the hazardous level, still many people are found allergic to them. The heating type devices, which evaporate the Pesticide diluted in Solvent are of constant evaporation type. The evaporation rate is set to a level, that when switched on it saturates the fresh air in the room to required air bourn potency in about 10 minutes for effective mosquito repelling effect. After this initial start-up phase these devices keep on evaporating at same rate which is higher for a saturated volume of air.

To address above limitation and to provide location and condition based flexibility, and to optimize the evaporation rate, this design is suggested. The device shown in Fig 1, basically is a timer circuit which uses the Timer IC 555. The circuit used is floating point adjustment for ON and OFF cycles. The total cycles timer is set to 20 minutes. The adjustment of ON-OFF cycles is given between 6 Minutes ON - 14 Minutes OFF to 16 Minutes ON - 4 Minutes OFF. This circuit inherently takes double the ON time when started up and completes the requirement of initial saturation of fresh room air. In next cycles, it follows the set cycles times as per the setting done by user to match field conditions. This optimizes the evaporation rate to the required level.

The device can be plugged in to the power point on the wall. The mosquito repelling devices available in market can further be plugged in the Optimizer device. The simple, user friendly Setting Knob can be set to the required level of evaporation rate.

Mosquito detects the presence of other animal by three different senses, namely Temperature, Moisture and CO2 in the air. The various field conditions like, seasonal changes, location of house, protections devices used, number of persons, air circulation in the room can change the mosquito population present in room. The current devices are tuned to address worst case scenario.

The timer circuit designed provides required flexibility on evaporation rate, thus optimise air bourn potency of harmful chemicals while maintaining the repelling efficacy. The manufacturing cost of this device is around USD 3.0. The savings those are seen on consumption of chemicals at different location since last 5 years is at a mean value of USD 0.5 per month. Additionally, the power consumption of the heater (50W), for 50% duty cycles setting can give savings of USD 0.5 per month.

The above small figures on savings will go astronomical considering the huge population of these devices. So to summarize, this small idea, which applied a known technology of timer circuits, to a very vital aspect of day to day life of humans, can bring in Health and Cost benefits to the masses.