Design of a conventional multi range voltmeter/ammeter

[dentjie88]

Hi there..
is anybody here know how to design one multi range voltmeter/ammeter by using a D’Arsonval meter with a full-scale deflection rating of 1mA and the internal coil resistance of 500Ω?
The measurement range of the voltmeter should cover the ranges as shown below.
Voltmeter Ammeter
1) 0-1V 0-10mA
2) 0-5V 0-50mA
3) 0-10V 0-100mA
4) 0-20V 0-1A
5) 0-50V 0-10A
6) 0-100V 0-20A
7) 0-200V 0-50A
8) 0-300V 0-60A
9) 0-400V 0-80A
10) 0-500V 0-100A
Can u tell me the step homework to do n any ref of this...
thx 4 helping... i really appreciate it...

 

[Averagesupernova]

It's all about ohms law. Nothing more. This sounds like homework BTW.

 

[oswaler]

Hi there, designing a multi range voltmeter/ammeter using a D’Arsonval meter with a full-scale deflection rating of 1mA and an internal coil resistance of 500Ω can be a bit complex, but I can provide some steps to help guide you through the process.

1. Determine the total number of ranges needed for both the voltmeter and ammeter. In this case, we have 10 ranges (0-1V, 0-5V, 0-10V, 0-20V, 0-50V, 0-100V, 0-200V, 0-300V, 0-400V, 0-500V) for the voltmeter and 10 ranges (0-10mA, 0-50mA, 0-100mA, 0-1A, 0-10A, 0-20A, 0-50A, 0-60A, 0-80A, 0-100A) for the ammeter.

2. Calculate the required series resistance for each range. To do this, we can use the formula R = (I x Rm)/Ifs, where R is the required series resistance, I is the full-scale current, Rm is the internal coil resistance, and Ifs is the full-scale deflection current. For example, for the first range of the voltmeter (0-1V), the required series resistance would be R = (1mA x 500Ω)/1mA = 500Ω.

3. Select a suitable range selector switch. This switch will be used to select the different ranges for the voltmeter and ammeter. It should have enough contacts to accommodate all the ranges needed.

4. Design the circuit for the voltmeter. This will involve connecting the series resistance, range selector switch, and the D’Arsonval meter in the appropriate configuration. You can refer to textbooks or online resources for sample circuits.

5. Repeat the same process for the ammeter circuit, taking into account the required series resistance for each range.

6. Test the voltmeter and ammeter circuits separately to ensure they are functioning properly.

7. Connect the two circuits together using a common power source and a common ground. This will allow for simultaneous measurement of voltage and current.

8. Test the combined circuit to ensure accurate