| 摘要 |
The torch (1) has two contact springs (7) differently connected with electric current by rotating a printed circuit board (8). A connecting device has an electronic circuit (10) arranged between lighting units i.e. LEDs, and the springs. The springs transmit electric current for signaling a logical condition to the electronic circuit. The electronic circuit individually feeds the lighting units with continuous electric current or with current pulses whose frequency is 20 cycles per second to 200 kiloHertz. The electronic circuit varies the pulse-pause ratio depending on the logical condition. |
