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How much voltage appears across a zener diode when it is forward-biased?
Wiki User
∙ 10y ago
That depends on the zener voltage rating:
- "low voltage" zeners are just a simple single diode, the zener diode
- "high voltage" zeners contain 2 back to back diodes in one package, the zener diode and an ordinary diode that is reverse biased when the zener diode is forward biased to block forward conduction of the zener and protect it from overcurrent damage if installed backwards by mistake
Thus in "low voltage" zeners when forward biased they will have a normal diode drop (e.g. 0.7V), but "high voltage" zeners when "forward biased" they will act open due to the reverse biased blocking/protection diode in series with the zener.
Wiki User
∙ 10y ago
Anonymous
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How does the cut in voltage effects the output of a diode clipper?
For answering this question we have to consider the constant voltage drop model of the diode which says that if voltage across diode is less then its cut in voltage than assume diode to be open circuit and if it is greater then assume diode to be short circuit.Till the input voltage is less than the cut in voltage, diode is open circuit(thus no current through the circuit). Thus entire input voltage appears across the diode as output.When input voltage is greater than or equal to cut in voltage, then short circuit the diode. Thus, there will be no voltage drop across the diode as output.Thus cut in voltage decides when to consider the diode open circuit and when short circuit. It decides when the diode will have output when it will not.
How much voltage is there across a silicon diode when it is forward biased?
0.7 The voltage across a silicon diode when it is forward biased should be greater than or equal (>=) 0.7volts.
When biased correctly a zener diode acts as?
a diode and it has a constant voltage across it ANSWER: acts as a voltage regulator if enough current flows to create a breakdown voltage.
When temperature increases voltage across diode with constant current?
The voltage across a semiconductor diode (and across the base/emitter junction of a transistor) decreases as temperature increases: the actual figure is -2mV/°C.
What is the voltage across diode carrying a constant current?
increases
How does the cut in voltage effects the output of a diode clipper?
For answering this question we have to consider the constant voltage drop model of the diode which says that if voltage across diode is less then its cut in voltage than assume diode to be open circuit and if it is greater then assume diode to be short circuit.Till the input voltage is less than the cut in voltage, diode is open circuit(thus no current through the circuit). Thus entire input voltage appears across the diode as output.When input voltage is greater than or equal to cut in voltage, then short circuit the diode. Thus, there will be no voltage drop across the diode as output.Thus cut in voltage decides when to consider the diode open circuit and when short circuit. It decides when the diode will have output when it will not.
What is the condition that prevent the current to pass across diode?
if the voltage across the diode is less than the cut-in voltage of that particular diode .
How much forward diode voltage is there with the ideal diode approximation?
Consider ideal diode to be connected in series with resistor of 6kSilicon diode forward bias voltage = 0.7 voltsCurrent across 6k resistor = (5-0.7)/6000 amperesVoltage across {resistor + diode}=4.3 + 0.7=5vIf silicon internal resistance is 6k then voltage across diode=5vIf external resistance is 6k and diode resistance is negligible then voltage across diode=0.7v
How much voltage is there across a silicon diode when it is forward biased?
0.7 The voltage across a silicon diode when it is forward biased should be greater than or equal (>=) 0.7volts.
When biased correctly a zener diode acts as?
a diode and it has a constant voltage across it ANSWER: acts as a voltage regulator if enough current flows to create a breakdown voltage.
When temperature increases voltage across diode with constant current?
The voltage across a semiconductor diode (and across the base/emitter junction of a transistor) decreases as temperature increases: the actual figure is -2mV/°C.
What is the voltage across diode carrying a constant current?
increases
What diodes are called catching diodes?
It's a diode that is used to limit a voltage to some desired value. Importantly, it's used to limit a transient voltage or an alternative voltage. The simplest example is that diode placed across a relay's inductive coil. As current is cut off through the coil, a large induced voltage appears that can cause damage to the circuit. A diode can be placed in circuit to catch/damp the induced voltage.
Why diode dose not allow to set voltage more than 0.7volts across it?
The barrier potential of the silicon diode is 0.7v if the applied voltage across it is more than this voltage then PN-junction of the diode breaks, once pn-junction breaks the voltage across the diode is constant, since it breaks at 0.7 this voltage will be constant and not exceed for any further increase in applied voltage -inform.mayaprasad@gmail.com The voltage across junction will only exceed from 0.7 volt (for silicon diode) in the case of reverse biasing the applied total voltage will appear across p-n junction. ANSWER: .7 VOLTS is an arbitrarily chosen number since a diode any diode have an exponential curve V vs I . This number is chosen when using a diodes but there are times when a greater or lesser voltage is chosen to reflect the application and the current trough the diode determine that. Example a diode gate diode will be chosen as .6 volts rather then .7v and a heavy conducting rectifier may have .8 volt to reflect closely the true value of the diode drop during real conditions
Is led a voltage controller or current controller?
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 is a barrier voltage?
The voltage across a forward-biased PN junction in a semiconductor diode or transistor.
How much voltage is there across a germanium diode when it is forward biased?
About 0.2V
