Como para usar a digital multímetro para medir a qualidade de estado sólido relé em o seguinte caminho
Solid state relay is referred to as SSR. It is a new type of non-contact switch composed of electronic components. It has the characteristics of reliable operation, fast switching speed and long life. It can replace conventional relays in control circuits.
Dois terminais de INPUT are input terminals, connected to control signals, and the other two terminals are output terminals, connected to relays. Solid-state relays can be divided em DC and AC solid-state relays according to load type. The former uses power transistors as switching elements, and the latter uses triacs as switching elements.
Princípio de AC zero-crossing solid state relay. O chamado zero-crossing significa que o tiristor é acionado quando o AC voltage é zero ou apenas cruza zero, que pode reduzir o impacto em o poder fornecimento quando o tiristor é virado on. Geralmente, o zero-cruzamento voltage é definido as ±25V. In this area, as long as the input signal is added, the SSR will be turned on. Quando o poder alimentação voltage é maior que ±25V, o SSR vai não ser virado ligado imediatamente quando a entrada sinal é adicionada. Ela vai apenas esperar até a alimentação caia para a próxima cruzamento voltage. O SSR é apenas virado on quando está em a zero área.
Quando detectando o SSR, você pode medir se há há DC tensão em a entrada fim. A presença de DC voltage indica que a entrada sinal é normal, e então medida se há está AC tensão em a saída fim. Se lá está, ela significa o SSR é normal. Se lá está nenhum ou a voltage drop é muito baixa, ela significa o estado sólido relé está danificado.
Use the diode setting of the digital multimeter to perform forward and reverse measurements on ①, ②, ③, and ④. According to the test data, when the red test lead is connected to pin ① and the black test lead is connected to pin ②, the meter displays a value of 1381 (1.381V). Exchange the test leads. During measurement, the meter displays the overflow symbol "1"; when the red test lead is connected to pin ④ and the black test lead is connected to pin ③, the meter displays a value of 543 (0.543V). When the test leads are exchanged for measurement, the meter displays the overflow symbol "1"; in the remaining In several test states, the instrument displays the overflow symbol "1". It is not difficult to draw the conclusion from this: ① and ② pins are the DC input terminals of the device under test, ① pin is the positive pole, ② pin is the negative pole, "1.381V" is the forward voltage drop of the light-emitting diode inside the solid-state relay; ③, ④ pins is the DC output terminal, pin ③ is the positive pole, pin ④ is the negative pole, "0.543V" is the forward voltage drop of the protection diode connected in parallel to the output terminal of the solid-state relay. Note that for solid-state relays without protection diodes at the output end, no matter how the test leads are exchanged to measure the ③ and ④ pins, the meter will display the overflow symbol "1". When using different types of digital multimeters to measure the internal light-emitting diodes of solid-state relays, the display value of some meters sometimes only flashes the reading momentarily, and then displays the overflow symbol "1". In this case, you can repeatedly exchange the test leads and test several times until the Draw test conclusions
