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An LED is a diode that emits light; diodes allow current to flow only one direction. The voltage applied to the diode attempts to force current to flow in a specific direction. If the voltage polarity is reversed, and current was flowing before (so there was a small voltage drop across the diode), current will cease to flow (assuming the voltage is not too high for the diode to handle), and (almost) all the voltage will be dropped across the diode (a small leakage current may flow, which means some of the voltage will not be dropped across the diode, but this is in the milli or micro range).
I would never define a diode as a "voltage controller" or "current controller". It could be either or both, from the above description.
What else can I help you with?
Can you run a 250 watt motor using a 1000 watt controller?
Yes, you can run a 250 watt motor using a 1000 watt controller as long as the voltage and current ratings are compatible. Be sure to adjust the settings on the controller to match the motor specifications to prevent damage.
What are voltage controlled voltage source?
when the magnitude of voltage of a source is controlled by another small voltage source in the circuit the former is called voltage controlled voltage source and the later is called controller voltage source.
Is led bulb resistive load?
No, LED bulbs are considered as a non-resistive load. They are semiconductor devices that convert electricity into light using a diode. LEDs operate by controlling the flow of current through the diode, rather than resisting it like traditional incandescent bulbs.
How does an 120VAC LED light bulb work?
LED's (Light Emitting Diodes) work on DC current, not AC, so the AC needs to be stepped down to an appropriate voltage via a transformer (probably only a few volts), converted to DC via a rectifier and filter (to smooth out the ripple current). there are a constant driver in side the 120V AC led light bulb , this driver transfer the AC to DC, so the led could work with DC.
Can a 12 2 low voltage line light up a 120 volt led light fixture?
What needs to be checked is the voltage of the low voltage line. If it is 120 v, that is suitable for a 120 v LED fitting. Second, is the line capable of carrying the current needed by the fixture. The answer to that is, probably, but it still needs checking.
what is current controller voltage source?
A voltage source whose voltage varies proportionally to a current flowing through some other path in the circuit.
Why must an LED always have a resistor connected in series with it?
An LED usually has a resistor connected in series with it because an LED (light emitting diode) is not linear in current to voltage (like a resistor) and has to be operated within specified current and voltage conditions. In most circuits the supply voltage is higher than the forward voltage of the LED so the LED would burn up from too much current without a current limiting resistor in series. The resistor sets the voltage and current to a good operating point (voltage and current) for the LED by dropping some voltage across it. The operating point varies depending on the size, type and manufacturer of an LED so the LED's data is used to select the right resistor size for a given voltage source.
What is voltage required for light emiting diode and the current consumption of light emiting diode?
Typically, about 12 volts DC is the maximum input for led stripes for lighting. If its in a controller or a computer it's typically 5 volts. By controlling the voltage you can control the brightness of the led (just keep it under 12). Now as for the current consumption that all varies upon the manufacture and size of the LED. If you have any paper work on it, it should tell you the recommended input voltage as will as the current consumption. If you don't just know that the current consumption of an LED is very very low.
Will a LED shine brighter if it is connected to a higher voltage?
A LED has a forward voltage drop dependent on it's composition. It is fairly constant within a small range of current flow. If the voltage is too high and the current is not limited, the LED will burn out. The brightness can be varied by varying the available current, but the voltage across the LED remains virtually the same.
Why does a Led have a 470 resistor connected to the LED?
A: That resistor is there to limit the current to the LED it can be any value if the voltage is decreased or increased or no resistor if the voltage across the led is equal to the forward voltage drop.
Why transistors are called transistors?
Previous answer "TRANSISTORS are current controlled voltage soruce" Nup, current-controlled current controller. Named as a contraction of TRANSference resISTOR.
What is forward current?
This is the current that flows under the application of a forward voltage. For eg. the dc forward current for an LED may be 30 mA when a forward voltage of 2.0V is applied.
How do you determine the resistant to be connected to a LED from 24V DC supply?
Find the LED rated voltage and current (eg 3.2 volts and 20 mA). If you are only using one LED, subtract LED voltage from supply voltage (eg 24 - 3.2 = 20.8) then divide by current in amps (eg 20.8 / 0.02 = 1040 or approx 1000). This gives the required resistance in ohms.
What size of resistor is required to operate the LED from a 9V battery?
In order to determine what size of resistor is required to operate an LED from a 9V battery, first start by knowing the current and voltage required for the LED. That information is available in the LED's specifications. For discussion purposes, lets assume a typical LED at 2.5V and 50mW. The translates to a forward current of 20mA. Build a simple series circuit containing a 9V battery, a resistor of an as yet unknown value, and the LED. By Kirchoff's current law, the current in the LED is the same as the current in the resistor, which is also the same as the current in the battery. This is 20ma. By Kirchoff's voltage law, the voltage across the LED plus the voltage across the resistor equals the voltage across the battery. This is 6.5V. (9 - 2.5) By Ohm's law, resistance is voltage divided by current, so the resistor is 6.5 / 0.02, or 325 Ohms. The nearest standard value to that is 330 Ohms. Cross check the power through the resistor. Power is voltage times current, or 6.5V times 0.02A, or 0.13W. A half watt resistor is more than adequate for this job.
Is led bulb resistive?
LEDs are semiconductors, diodes in particular. The current flowing in an LED is an exponential function of voltage across the LED. The important part about that for you is that a small change in voltage can produce a huge change in current. That is the most important concept of this article. Resistors aren't like that. The current and voltage in a resistor are linearly related. That means that a change in voltage will produce a proportional change in current. Current versus voltage is a straight line for a resistor, but not at all for an LED.Because of this, you can't say that LEDs have "resistance." Resistance is defined as the constant ratio of voltage to current in a resistive circuit element. Even worse, there's no real way to know exactly the relationship between current and voltage for any given LED across all possible voltages other than direct measurement. The exact relationship varies among different colors, different sizes, and even different batches from the same manufacturer.
What an led accepts whether ac or dc voltage?
A: A LED is a diode that emit photons when exited with enough current and/or voltage. it does not care where the source come from. for AC IT WILL WORK PROVIDED A SERIES DIODE IS ADDED that is there to prevent the led from burning up when the reverse voltage exceed the saturation current . these devices have a very low reverse voltage breakdown limitation and if they breakdown usually the power dissipation will be exceeded and blow up.
What is the voltage requirement for 1 yellow LED?
A: Usually LEDS are 1.8v but this varies from color to color and size. When a LED is bought that is when the voltage is current must be evident otherwise you need a VOM and a 9v battery and some resistors to find the voltage.
