A switch module with two sprung contacts in addition to a final "hard" contact allow for
three levels of illumination on various 2x123 LED heads; both buck and boost circuits. A
thin brass shelf is pressed into the tail of the E tube and rests on the existing shoulder.

As the switch module is pushed into the tail, against the cathode spring force, either by
pushing the tail button or screwing the cap down, one of the sprung pins contacts the brass
shelf. The first contact is connected in series with the cathode spring and a 80 ohm SMD
resistor. The first power level is then completed with 80 ohms of resistance which drops the
converter out of regulation and provides a low voltage to the LED for a dim level of
illumination. As the switch is further depressed, a second pin that is further away from the
shelf then contacts the shelf. It is connected in series with a 30 ohm resistor to the cathode
spring. There are now two parallel paths of resistance between the cathode spring and the
battery tube completing the power circuit. The total resistance has dropped to 22 ohms
approximately. This resistance still drops the converter out of regulation but supplies a
higher voltage to the LED with a resulting higher level of illumination. Further depression
brings the brass switch base in contact with the battery tube lip and the power circuit is
completed with no resistance. This allows the converter to operate and provide the set
level of constant current to the LED. The High Level is provided.
A DownBoy 917 on 2x123 with this switch provided the three relative lux readings: 230,
820 and 4070. A BadBoy 611 on 1x123 was tested with this switch and the three relative
lux readings were 27, 230 and 3500. The lux readings are not to be compared between the
two drivers as the distance to light meter was not the same.