Read about diode circuit | 9 Discussions | Page 1

  1. J

    Engineering DC bias current and small-signal resistance

    We are given that ##i_D = 8\cdot 10^{-12} (e^{v_D/20m} - 1)## Hence ##i_D' = e^{50 v_D}/2500000000## and ##i_D'' = e^{50 v_D}/50000000## Then I have that ##\delta i_D \approx\frac{ e^{50 v_D}}{2500000000} \cdot \delta v_D = \delta v_D / 5## Cancelling ##\delta v_D## from boh sides and solving...
  2. C

    B Ohmic Resistance in diodes

    Well I was just wondering how ohmic resistance works in a diode . I mean lets take forward bias mode.In forward bias mode electrons are diffused from the n type region to the p type region.The depletion layer still exists but is very narrow.So according to Drude model of ohmic resistance...
  3. C

    B Semiconductors confusion

    Assume we have a diode . We connenct the negative terminal of the battery(anode) to the n type region and we connect the positive terminal of the battery to the p type region of the battery.The net force forces electrons to start flowing from the n type region to the p type region.As long as we...
  4. C

    B Semiconductor physics: Voltage below forward voltage

    Assume we have a diode closed circuit.We connect the p type region of the diode to the positive terminal of the battery(cathode).We connect the n type region of the diode to the negative terminal of the battery(anode).The voltage of the battery is 0.3V .The diode%s intristic se miconductor is...
  5. archaic

    Load resistance in voltage regulator

    Homework Statement [/B] I want to find the minimum resistance ##R_L## so as to maintain ##V_z##(voltage of the zener corresponding to the minimum current ##I_{z_0}##) across the same resistor ##R_L##. Homework Equations ##V_z##(voltage of the zener corresponding to the minimum current...
  6. V

    PNP Transistor voltage calculation

    For the B) part, I don't get why is it that for calculating voltage between collector an the emitter (Vce) I take into account diode on base (0.7V), whereas for part A) it's ignored? Why is Vce in part A and part B are calculated differently? Why is it that in part A voltage of 0.7V isn't taken...
  7. DakotaE

    Trying to determine the size of Diodes required

    Hey All, i just joined today to try and figure out what size of diodes i need for the project im working on. I am working on installing a new Light Bar and Flood Lamps to my Jeep to get better light at night. This is my hope to accomplish: Relay 1 will be used to turn the LED Light Bar and...
  8. V

    Circuit with two voltage sources, finding voltage at nodes

    Okay, so why is it that Vc assumed to be 12v - 0.7v (D1), how about contribution from the 9v battery?? Why is this not affecting the voltage at node C? Why Vc isn't 9v - 0.7v (D2) = 8.3v?
  9. whatphysics

    Finding the forward current of diode

    Homework Statement A Si diode is operated at the room temperature (27 °C). For a forward current of 1 mA, the voltage VD is found to be 0.9 V. If the VD is 1 V, the forward current = _____ mA. Given that nVT = 26 mV The answer is 46.81 Homework Equations Shockley diode equation? The Attempt...