| 摘要 |
1,259,363. Transistor switching circuits. TOKAI RIKA DENKI SEISAKUSHO K.K. 24 March, 1969 [22 March, 1968], No. 15238/69. Heading H3T. [Also in Division G4] In a vehicle direction indicating and brake lamp system a lamp energizing circuit T5-T10 is operable by a first transistor T1, T2, T3 (Fig. 1), T1, T2 (Fig. 3) on application of a direction indicating signal b, the lamp energizing circuit is also operable on application of a brake signal c and a second transistor T4 is arranged to be operated by the direction indicating signal b to render the brake signal ineffective. When a direction indicator signal b in the form of pulses from a bi-metal or cam-operated flasher occur transistors T1-T4 (Fig. 1) conduct. This causes a bi-stable pair of transistors T5, T6 to conduct and light lamp L1. Further bi-stable pairs of transistors T7, T8 and T9, T10 then conduct in sequence as controlled by RC timing circuits R14, C2 and R19, C3 so that the further lamps L2 and L3 are lit in sequence. All the lamps go out when the direction signal pulse b ends and the transistors T1-T10 turn OFF. The direction signals b to transistor T4 are fed via a diode D2 to a smoothing circuit R4, C1 which causes the transistor to be held ON whilst direction signals b are present so that if brake signals c are also applied they are shunted to ground via T4 and do not effect the direction signal. If only a brake signal is present only transistor T3 conducts and causes simultaneous switching of all the transistors T5-T10 to simultaneously light all the lamps L1, L2, L3. The diodes D1-D3 provide isolation of the control gating transistors T1- T4. A pair of lamp groups L1-L3 is provided to the left and right side of the vehicle. In a modification (Fig. 2, not shown), transistor T4 may be connected with its emitter and collector between point P9 and diode D1 so that it is rendered conducting by a brake signal c or non- conducting by the direction indicator signal b. In a further modification (Fig. 3) the brake signal c causes a transistor T3 to conduct and simultaneously light all the lamps L1-L3. When a direction indicator signal b is also applied transistors T1 and T2 conduct to produce sequential lighting of the lamps and transistor T4 conducts to prevent operation of the brake signal transistor T3. |
