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Use a shunt made a precision but very low resistance. Place the shunt in series with the ckt. Measure the voltage drop, and do the math.
The ammeter function of most voltmeters uses two ranges- about .25ohms for the 10 amp range, and a higher value for lower currents on the order of 250ma where a larger shunt won't affect the ckt too much and give a more accurate reading. Many meters are damaged when this function is used on low range first with 10 amps applied!
Wiki User
∙ 15y ago
Wiki User
∙ 10y agoCurrent is measured by placing your multimeter leads in the circuit in series with the multimeter set to current.
The probes run the sample of current and detect the amount of electomagnetic force coming from the outside of the wire. With this they can tell how much current is in the wire. The downside is that it isn't 100% accurate. The upside is that most of electronics isn't exact. The orginal current isn't disturbed during this process because of the conversion to reading the magnetism coming from the wires and not having to use both the positive and negative of the current source.
Voltage is measure by placing your multimeter leads in parallel with the circuit with the multimeter set to voltage.
Voltage probes work in that a "potential force" is created by sampling both the ground and the positive of an unknown voltage source. The probes can only measure 1.5 amps max. on most electric multimeters (more than that and you will blow a capacitor...i.e. random and nonzero meter readings...). It takes the orginial source and runs it through a resistor with known value. The difference in voltage value before the resistor and after the resistor gives the multimeter the actual unknown voltage. The good thing is that you only have to sample a 10th of the current to get a good voltage value. The bad thing is that you change the orginal current when measuring this way (to include introducing reverse flow of electromagnetic force). An alternative is to use a multimeter with magnetic probes that don't have to touch the voltage being measured.
Wiki User
∙ 12y agoto measure current, place the ammeter in the path of the current flow so that the electrons must flow through the ammeter. make sure the power is on. polarity is critical.
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What function in a circuit for a switch?
A switch is a make - break device. Its function is a circuit is to make and break the current flow of the circuit that it is in. This action then starts and stops the load that is connected in the circuit.
Why does a switch make a light turn on and off?
The purpose of a switch is to stop and start a current flow in a circuit. The stopping of a current flow in a circuit effects the load of the circuit by stopping its action. Resuming the current flow in a circuit also resumes the action of the load.
Multimeter that can measure inductance capacitance frequency voltage current and resistance in one system?
Many mutlimeters have this capability. You'll probably want a digital multimeter. If you do a good search, this should be easy to find. You'll need to read through the specifications carefully to make sure you find one that gives the level of accuracy you're looking for. the more accurate it is, the more you'll pay.
What are the precaution before using a multimeter dc voltmeter and dc ammeter?
Make sure the the Leeds are inserted in the right hole. Make sure that the meter is set to the range of voltage or current you expect
How do you measure a resistor using multimeter?
a multimeter probably has a Ohm meter as well. If yes, use it and make sure you have the correct scale adjusted. If there is no Ohm meter you should calculate the resistance using Ohms Law. So if you use your multimeter as an Amp meter (in series with the unknown resistor) and you apply a know voltage across you should be able to calculate the resistance by dividing the voltage you applied by the current you meassured (R=v/I) ANSWER: 1 make sure ther is no external power connected 2 short the leads together and adjust for zero reading on the meter. This step is necessary to eliminate the internal battery drifting with time. Unlike voltage and amps reading the scaling of the meter is not important to begin with since a peg meter or a overflow will not destroy the meter immediately but do change the scale to get maximum deflection or digital display.That it
How do you check amp draw?
Amperage is measured by a multimeter. First determine the amperage rating on the multimeter. Next, select the appropriate setting on the tool. The next step is to set the range on the multimeter. Make sure to plug the leads into the appropriate terminals. Run the circuit through the multimeter to measure the current. Turn off the breaker, make sure the AC circuit is turned off, then rewire the circuit.
What purpose might the multimeter serve in maintaining and troobleshooting a computer network?
With the multimeter you can measure the voltage on parts of the circuit board. You can also measure the resistance of resistors and make sure there are no short circuits in the circuit.
How can you check Integrated Circuits with a multimeter?
To check the IC by the multimeter, you have to make sure that the pointer points at the current. You can then connect the multimeter across the check the IC.
If you make a mistake in polarity when meauring the value of dc voltage in a circuit with a digital vom what will happen?
absolutely nothing happens...just reverse the probes of multimeter & measure it again...this time around it should come positive...
How do you measure a thyristor?
Many users of thyristors and diodes lack the proper equipment to make measurements of semiconductor parameters. The readily available battery operated multimeter is often used to try to determine the difference between acceptable and non-acceptable devices using a resistance reading. A reading of this type can lead to incorrect conclusions. MULTIMETER MEASUREMENTS The multimeter is generally used to measure the DC resistance between anode and cathode of thyristors and diodes and also the gate to cathode on thyristors. These measurements are of the "off state" or blocking voltage of the device. The only valid readings are "open circuit" and "short circuit". The anode to cathode or gate to cathode measurement must register a short circuit in both directions ( forward and reverse polarity) for the device to be declared short and infinite resistance for an open circuit. The measurement of resistance with a multimeter is an inappropriate measurement technique for separating good devices from bad. When a resistance measurement is taken with an multimeter, the internal battery voltage is typically in the range 1.5V to 15V and the leakage current of the device at this voltage will determine the measured resistance. A semiconductor has a non-linear blocking voltage/leakage current characteristic and hence a non-linear resistance curve. The blocking voltage of a thyristor is defined as the voltage at which it reaches a specified leakage current at the defined temperature. Therefore devices can have a variety of leakage current characteristics and still be within specification. PRECAUTIONS 1. Ensure that the resistance reading is only being taken across the device and not across something in parallel with it. 2. If a capsule type device is being measured, make sure that it is under sufficient load to ensure that the internal components are pressed together and high resistance readings are avoided. SUMMARY A multimeter resistance measurement is not recommended for determining acceptable semiconductor devices. As a quick check for devices in a circuit, a multimeter will allow you to determine if a device has failed catastrophically. The device with the lowest leakage current at 3V is not necessarily the one with the lowest leakage current a high voltage
What is added to a circuit to make the current smaller?
The reduction of voltage or the increase of resistance will reduce the current in a circuit.
How do you go about tracing an electrical problem that is draining the battery on a Hyundai Elantra?
If you are not comfortable or knowledgeable with the electrical system of a car, have it checked by a mechanic. If the above solution isn't your problem, you can isolate what's drawing the current using this method. You need a multimeter capable of reading AMPS. Remove the ground battery cable and place the multimeter between the battery cable and the battery. Make sure you DON'T run your car like this!! With the car OFF, see how much current is being drawn from the battery. Some current draw is normal, as your cars computer and radio memory functions need power to retain their settings. Start by removing a single fuse and replacing it, each time checking the current on the multimeter. By process of elimination, if you pull the fuse on the circuit that's causing the trouble, the current draw will drop. There's your troubled circuit. Then you'd need a wiring diagram, which you can find on hmaservice.com, and trace down the short circuit.
How can you make an electric current stronger?
An electric current through a resistive circuit can be increased by decreasing the resistive load or increasing the voltage of the circuit.
How is an ammeter connected in a circuit in order to read the current flowing in the circuit?
In series with the circuit and never in parallel. The reason being that it will cause the circuit total resistance to drop which will make the circuit draw excessive current. That's a short circuit actually.
What function in a circuit for a switch?
A switch is a make - break device. Its function is a circuit is to make and break the current flow of the circuit that it is in. This action then starts and stops the load that is connected in the circuit.
Why does a switch make a light turn on and off?
The purpose of a switch is to stop and start a current flow in a circuit. The stopping of a current flow in a circuit effects the load of the circuit by stopping its action. Resuming the current flow in a circuit also resumes the action of the load.
Why meter ampere was connected in series and voltmeter was connected in parallel in a circuit?
An ammeter is used to measure the current through a circuit and thus it must be in series with that load. Also, it's resistance is so low that it cannot be connected in parallel since it will result in a short circuit. A Voltmeter is intended to measure the voltage across a circuit and thus it must be connected in parallel. It has a very high resistance such that connecting it in series with a circuit will lender the circuit useless or inoperative.
