tan timer schematics

This timer is intended for individuals seeking to achieve a tan while minimizing excessive exposure to sunlight. A rotary switch adjusts the timer based on six categorized photo-types. A photoresistor modifies the preset time value in relation to sunlight brightness. Upon completion of the preset time, a beeper produces an intermittent signal, which can only be silenced by completely turning off the circuit using switch SW2.

The timer circuit is designed to enhance user safety while tanning by automatically adjusting exposure times based on the user's skin type and current sunlight conditions. The rotary switch allows the user to select one of six predetermined photo-types, each corresponding to different skin sensitivities to UV radiation. This selection is crucial as it informs the circuit of the maximum safe exposure time.

The photoresistor plays a vital role in this timer circuit by detecting ambient light levels. It is connected in such a way that it influences the timer's countdown duration. When sunlight is detected, the resistance of the photoresistor decreases, which in turn extends the preset time. This feature ensures that the user is not exposed to harmful UV rays for longer than necessary, as the circuit adapts to real-time sunlight conditions.

The beeper serves as an alert mechanism, providing an intermittent sound to notify the user when the preset time has elapsed. This auditory signal is crucial for prompting the user to either stop tanning or take necessary precautions. To silence the beeper, the user must completely deactivate the circuit using switch SW2, ensuring that the timer cannot be inadvertently reset or ignored.

Overall, this timer circuit combines user-friendly adjustments with intelligent light-sensing technology to promote safer tanning practices. It is recommended that users familiarize themselves with the operation of the rotary switch and the implications of varying sunlight conditions to maximize the effectiveness of this tanning timer.This timer was designed for people wanting to get tanned but at the same time wishing to avoid an excessive exposure to sunlight. A Rotary Switch sets the timer according to six classified Photo-types (see table). A Photo resistor extends the preset time value according to sunlight brightness (see table). When preset time ends, the beeper emits an intermittent signal and, to stop it, a complete switch-off of the circuit via SW2 is necessary. 🔗 External reference