Approximately 10% of patients report an allergy to penicillin. However, the majority of patients (greater than 90%) may not truly be allergic. Most people lose their penicillin allergy over time, even patients with a history of severe reaction such as anaphylaxis.
Additional lighting equipment is often necessary to compensate the low levels. Earlier it was common with light levels in the range 100 - 300 lux for normal activities. Today the light level is more common in the range 500 - 1000 lux-depending on activity.
PCs a white backlight or sidelight is required for a homogeneous illumination of the LCD colors. The white LED seems to be a good choice for backlight since it requires less power and space compared to the commonly used CCFL (Cold Cathode Fluorescent Light) backlight. The typical forward voltage of a white LED is in the range of 3V to 5V. Since the best choice to power white LEDs is a constant current source and the input voltage range of a Li-Ion battery is below or equal to the LED forward voltage a new power supply solution is required.