| 摘要 |
A two terminal voltage tester/meter, which between its two terminals clamps (10, 12) is fitted with a resistive load (22, 24, 26, 28). The apparatus is fitted to indicate, by means of light emitting diodes (42, 42', 58) the voltage present, as well as any possible fault in the circuit. This works this way because the apparatus between the clamps also contains a functional voltage indication stage, as an active component, together with a fault indicator stage connected in series to the voltage indication stage. The voltage indication stage includes at least three primary branches connected in parallel (34, 36, and 38). The first primary branch (34) consists of a first diac (40), i.e. a bi-directional diode thyristor with two legs, and a first light emitting diode (42). The second primary branch (36) consists of a load condenser (46) and the third primary branch (38) a protective resistor (48). The fault indicator stage consists of at least two secondary branches (52,54) connected in parallel. The first secondary branch (52) consists of a second diac (56) and a second light emitting diode (58) connected in series. The second secondary branch (54) consists of a resistor.<IMAGE> |
