MULTI-VOLTAGE DISINFECTOR TIMING CIRCUIT

摘要

A contact lens disinfector unit having multi-voltage capabilities includes a timing circuit for controlling the duration of operation of a contact lens disinfector heater. The circuit is particularly suitable for use with a heater consisting of a positive temperature coefficient thermistor. In the preferred form, the contact lens disinfector units are suitable for use regardless of the voltage value at an electrical outlet receptacle providing power to such a disinfector unit. Depending upon the country in which the device is used, voltages can vary generally anywhere from 95 AC volts to 256 volts AC. Positive temperature coefficient (PTC) thermistors are capable of operation irrespective of such variable voltage range and unique control circuit disclosed is capable of timing control and operation where the input voltage has such a wide value range.