Tension in the power supply network can be considered the electromotive force (EMF) of a source of current or voltage drop on this specific consumer. This size can be measured by the special device or to calculate if other parameters are known. When in network alternating current, but distinguish effective and amplitude value of tension.
It is required to you
- - tester;
- - power supply network and consumer.
Instruction
1. For determination of EMF on a current source, connect a tester to its clips. On its display the value of tension will appear. At setup of the device at first expose it on the highest tension, then, gradually increase its sensitivity that the device did not fail. At measurement of a direct current surely establish this control on the device and observe polarity of its connection. At measurement of EMF in alternating current mains, polarity it is not necessary to observe.
2. At measurement of EMF of a source of alternating current, consider that the device shows effective value of tension which performs work on transferring of a charge. Find amplitude value of tension, having increased the measured size by a root square of 2. For example, if the tester showed in household network 220 V, then this effective value of tension. Then the amplitude value will be 220 * √ 2≈311 V.
3. At voltage measurement on any consumer connect a tester in the mode of measurement of this size to its clips. After that connect the consumer to network. For a direct current observe polarity, calculate effective and amplitude value of alternating voltage by the described technique.
4. If there is no opportunity to measure tension in network directly, calculate it. Measure current in networks, and the general resistance of the loading connected to a current source. Find tension in network U, having increased value of current in amperes of I on electrical resistance R (U=I*R). For example, if current is equal in network 2 A, and the general resistance of 140 Ohms, then tension U=2*140=280 V will be equal in it.
5. To find current source EMF, on current, learn the internal resistance of a source of current of r except resistance of the site of a chain. Then, to determine the current source EMF in network find the sum of resistance and increase it by EMF current = I * (R + r). For example, if in the same example the internal resistance of a source of current of 20 Ohms, then V EDS=2*(140+20)=320.