As in the current measurement, measurement of electrical voltage with a voltmeter also has limitations, prisoner in Rm meter measuring limit voltage limiting capability. Raising the voltage measurement performed by placing detainees at the meter base ser Rs. Prisoners energized Rs series of Is, which flows through the meter for Im Rm.
design Voltmeter
When a D’Arsonval meter coupled with a series that serves as a detention prisoner multiplier will change d’Arsonval movement into a direct current voltmeter, as shown in Figure 6:25.
Figure 6.25 Basic circuit Direct current voltmeter
Prisoners multiplier Rs limits the current to the coil rotary (Rm) not to exceed the full-scale current Idp. A direct current voltmeter measures the potential difference between two points in a circuit direct current and thus are connected in parallel to a voltage source or circuit components. Limit gauge voltmeter (V), which is formed of d’Arsonval meter is dependent on the size of the multiplier resistance value Rs formulated as follows,
Rs = (V / Im) – Rm
For example, if the meter base used have the following data, Rm = 100 ohm and current full deflection Idp = 1 mA. The meter will be used as a voltmeter to measure DC voltage limit V = 10 volts, then the multiplier resistance value is Rs = 9900 ohms.
Figure 6:26 Voltmeter Standard Multi Limits Measure
Figure 6.27 Voltmeter Panel
When the direct current voltmeter is coupled with a rectifier circuit (rectifier) which converts alternating current into direct current, the meter can be used to measure the alternating voltage. So the problem of alternating current measurements obtained using a series of either half wave rectifier uses only a single diode rectifier or full Wafe using four diodes in a bridge circuit. Figure 6.28 shows the schematic voltmeter alternating current that uses a diode
Figure 6.28 Schematic Flow voltmeter Round Robin