amplitude voltage measure with an oscilloscope.First post on a DC voltage, in the form close to the estimated maximum value of the measured.Install easy-to-scale measurements.Calculate how much voltage falls to one division of the scale.Then, without changing the oscilloscope settings, instead of DC post it measured.Then, determine the scale of its amplitude.
If the voltage is constant, do not perform any calculations: its value is equal to the current amplitude.
If the voltage varies sinusoidally, divide its peak value at the root of two, and get it the RMS value.
for bipolar rectangular pulses, only if the voltage changes polarity, but never gets to zero for a long time, take the current value equal to the maximum, regardless of the duty cycle.For
unipolar rectangular pulses when the voltage becomes equal to zero, the maximum, get the relationship between the pulse duration and the total period, and multiply it by the peak value, and get active.For unipolar meander current value is equal to half the amplitude.
If the voltage varies in a complicated law, put it in the current amplitude value mathematically extremely difficult, and in some cases impossible.Load source optocoupler consisting of an incandescent lamp and photoresistor.Optocoupler with LED will not do.Lamp pick up in such a way that it is minimum load on the source and the light dimly.Measure the resistance of the photoresistor.Then switch the lamp on the DC power supply.Adjust it so that the resistance of the photoresistor was the same.The DC voltage across the lamp will be equal to the current value is measured, with the only difference being that the first can be easily measured by a conventional voltmeter.
Tip 2: How to convert amps to volts
Amps and Volts - standard system units current and voltage (EMF), respectively.Directly convert amps to volts can not, because they are completely different although "related" units.However, in practice often have to travel a similar conversion.This will usually require additional information.
- - Ammeter;
- - ohmmeter;
- - power meter;
- - Calculator;
- - the technical documentation.
To convert amps to volts , verify the power of the appliance, or the resistance of the conductor.Power devices can be found in the technical documentation or on the device.If the documents are not available on the device, look for its technical parameters (power) on the Internet or measure it with a power meter.To determine the resistance of the conductor, use an ohmmeter.
If you know the power of the appliance, then transfer amperes volts use the following formula: U = P / I, where: U - the voltage in volts, P - power, in watts, I -current in amperah.Pod "power" means the power consumption of the appliance.
Primer.Izvestno that the motor provides the power of 1900 watts.Its efficiency is 50%.At the same time, the engine is detected fuse 10 amper.Vopros.Na a motor rated voltage? Reshenie.Dlya calculating the power consumed by the appliance divide it effective power efficiency at 1900/3800 = 0.5 (W) .To calculate the voltage, power divideamperage: 3800/10 = 380 (V) of the motor must be .Otvet.Dlya voltage of 380 volts.
If you know the electrical resistance of a conductor or a simple heating appliance (such as iron), then to translate amps in volts use Ohm's law: U = IR, where R - resistance of the conductor in ohms
Primer.Soprotivlenie spiral electric stoves is 110 ohms.After the slab passes a current of 2 ampera.Vopros.Chemu equal to mains voltage? Reshenie.U = 2 * 110 = 220 (V) .Otvet.Napryazhenie in power - 220 volts.
Primer.Soprotivlenie spiral bulbs for flashlight - 90 th.When enabled, it passes through a current of 0.05 amper.Vopros.Skolko standard batteries required to operate the flashlight? Reshenie.U = 0.05 * 90 = 4.5 (V).EMF of the battery is 1.5 volts, therefore, required for torch 4.5 / 1.5 = 3 such element.
- how to translate ohms