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Let's discuss two types of negative differential resistance ( out of 4)

A) a forward voltage causes current to rise quickly like a hot resistor but due to special Fermi Levels in a semi-conductor, a threshold is reached resulting in current to drop abruptly which follows the same path back with some hysteresis.

• example is the Gunn Diode for extreme high microwave resonators

B) A forward voltage occurs with little or no current until a threshold is reached and then the voltage collapses to a low voltage and then rises like a resistor with more voltage and current.

• example is a DIAC which is used to trigger SCR's , ( similar to a 3 leaded Unijunction and SCR characteristics except with 2 leads.)

• example gas tube ( neon, transient suppressor, fluorescent , air arc (ESD) corona, etc) these have much high trigger levels which is sensitive to gas pressure and vacuum. In air BreakDown Voltage (BDV) that is 1kV/mm to 3kV/mm

  • Here a dielectric gas, which is an insulator, excites electrons under an electric field until the the electrons escape the outer orbit, and depending on the gas and current may emit X-Rays like FL tubes which hit the phospors inside glass and secondary electron emission results in a lower visible wavelength and conducting lots of ions which drops the voltage as current rises with a -ve R.

Let's discuss two types of negative differential resistance ( out of 4)

A) a forward voltage causes current to rise quickly like a hot resistor but due to special Fermi Levels in a semi-conductor, a threshold is reached resulting in current to drop abruptly which follows the same path back with some hysteresis.

• example is the Gunn Diode for extreme high microwave resonators

B) A forward voltage occurs with little or no current until a threshold is reached and then the voltage collapses to a low voltage and then rises like a resistor with more voltage and current.

• example is a DIAC which is used to trigger SCR's , ( "somewhat" similar to a 3 leaded Unijunction and SCR characteristics except with 2 leads.)

• example gas tube ( neon, transient suppressor, fluorescent , air arc (ESD) corona, etc) these have much high trigger levels which is sensitive to gas pressure and vacuum. In air BreakDown Voltage (BDV) that is 1kV/mm to 3kV/mm

  • Here a dielectric gas, which is an insulator, excites electrons under an electric field until the the electrons escape the outer orbit, and depending on the gas and current may emit X-Rays like FL tubes which hit the phospors inside glass and secondary electron emission results in a lower visible wavelength and conducting lots of ions which drops the voltage as current rises with a -ve R.

Let's discuss two types of negative differential resistance ( out of 4)

A) a forward voltage causes current to rise quickly like a hot resistor but due to special Fermi Levels in a semi-conductor, a threshold is reached resulting in current to drop abruptly which follows the same path back with some hysteresis.

• example is the Gunn Diode for extreme high microwave resonators

B) A forward voltage occurs with little or no current until a threshold is reached and then the voltage collapses to a low voltage and then rises like a resistor with more voltage and current.

• example is a DIAC which is used to trigger SCR's , ( similar to a 3 leaded Unijunction and SCR characteristics except with 2 leads.)

• example gas tube ( neon, transient suppressor, fluorescent , air arc (ESD) corona, etc) these have much high trigger levels which is sensitive to gas pressure and vacuum. In air BreakDown Voltage (BDV) that is 1kV/mm to 3kV/mm

  • Here a dielectric gas, which is an insulator, excites electrons under an electric field until the the electrons escape the outer orbit, and depending on the gas and current may emit X-Rays like FL tubes which hit the phospors inside glass and secondary electron emission results in a lower visible wavelength and conducting lots of ions which drops the voltage as current rises with a -ve R.

p.s. I have no idea where Wiki got these hypothetical curves, but I added the coloured ones (not to voltage scale)

Let's discuss two types of negative differential resistance ( out of 4)

A) a forward voltage causes current to rise quickly like a hot resistor but due to special Fermi Levels in a semi-conductor, a threshold is reached resulting in current to drop abruptly which follows the same path back with some hysteresis.

• example is the Gunn Diode for extreme high microwave resonators

B) A forward voltage occurs with little or no current until a threshold is reached and then the voltage collapses to a low voltage and then rises like a resistor with more voltage and current.

• example is a DIAC which is used to trigger SCR's , ( similar to a 3 leaded Unijunction and SCR characteristics except with 2 leads.)

• example gas tube ( neon, transient suppressor, fluorescent , air arc (ESD) corona, etc) these have much high trigger levels which is sensitive to gas pressure and vacuum. In air BreakDown Voltage (BDV) that is 1kV/mm to 3kV/mm

  • Here a dielectric gas, which is an insulator, excites electrons under an electric field until the the electrons escape the outer orbit, and depending on the gas and current may emit X-Rays like FL tubes which hit the phospors inside glass and secondary electron emission results in a lower visible wavelength and conducting lots of ions which drops the voltage as current rises with a -ve R.

Let's discuss two types of negative differential resistance ( out of 4)

A) a forward voltage causes current to rise quickly like a hot resistor but due to special Fermi Levels in a semi-conductor, a threshold is reached resulting in current to drop abruptly which follows the same path back with some hysteresis.

• example is the Gunn Diode for extreme high microwave resonators

B) A forward voltage occurs with little or no current until a threshold is reached and then the voltage collapses to a low voltage and then rises like a resistor with more voltage and current.

• example SCR which triggers using two back to back transistors and then it self biases and stays latched like a memory state with DC until the Ih holding current is reached and then it loses sufficient bias to maintain being latched up.

• example gas tube ( neon, transient suppressor, fluorescent , air arc (ESD) corona, etc)

  • Here a dielectric gas, which is an insulator, excites electrons under an electric field until the the electrons escape the outer orbit, and depending on the gas and current may emit X-Rays like FL tubes which hit the phospors inside glass and secondary electron emission results in a lower visible wavelength and conducting lots of ions which drops the voltage as current rises with a -ve R.

p.s. I have no idea where Wiki got these hypothetical curves, but I added the coloured ones (not to voltage scale)

Let's discuss two types of negative differential resistance ( out of 4)

A) a forward voltage causes current to rise quickly like a hot resistor but due to special Fermi Levels in a semi-conductor, a threshold is reached resulting in current to drop abruptly which follows the same path back with some hysteresis.

• example is the Gunn Diode for extreme high microwave resonators

B) A forward voltage occurs with little or no current until a threshold is reached and then the voltage collapses to a low voltage and then rises like a resistor with more voltage and current.

• example is a DIAC which is used to trigger SCR's , ( similar to a 3 leaded Unijunction and SCR characteristics except with 2 leads.)

• example gas tube ( neon, transient suppressor, fluorescent , air arc (ESD) corona, etc) these have much high trigger levels which is sensitive to gas pressure and vacuum. In air BreakDown Voltage (BDV) that is 1kV/mm to 3kV/mm

  • Here a dielectric gas, which is an insulator, excites electrons under an electric field until the the electrons escape the outer orbit, and depending on the gas and current may emit X-Rays like FL tubes which hit the phospors inside glass and secondary electron emission results in a lower visible wavelength and conducting lots of ions which drops the voltage as current rises with a -ve R.

p.s. I have no idea where Wiki got these hypothetical curves, but I added the coloured ones (not to voltage scale)