Diodes are semiconductor components made from a P-type and N-type silicon material, that allows current to only flow in one direction.

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Germanium Power Diodes

Why don't the make germanium power diodes for their lower voltage drop? I have used a diode connected junk-box germanium power transistor for a oneoff in house job because it out performed a silicone ...
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41 views

Feeding arduino with ATX standby power

I'm designing an Arduino shield to allow the Arduino to control, among other things, an ATX power supply -- I'm running GPIO pins to the PS_ON and P_OK pins of the ATX. I would like to be able to run ...
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51 views

Is it safe to use a bridge rectifier at (up to) its rated current, at DC?

I'm looking through my local components distributor's online catalogue, and bridge rectifiers are significantly cheaper for a given current rating than individual diodes. I'm likely to need two or ...
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1answer
51 views

Is a dead diode actually a shorting?

I had a little project running with an arduino pro mini. had external psu connected and connected my programmer with power onto it. smoke came up. hole in the diode. now my question: Is a dead diode ...
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1answer
52 views

Correct design for large contactor circuit?

After some advice here I'm wondering if this is the correct design of my circuit. I'm now using a SSR as the control device to the contactor. The diode, I believe, should not only protect the SSR ...
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1answer
20 views

Relationship between band gap and built in potential for PN Junction Diode in equilibrium?

I wanted to know the relationship between the band gap (Eg) of the p/n regions in a diode and the built in potential in equilibrium. My intuition says that Eg = e*Vo. I did a small calculation for ...
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2answers
44 views

Portable phone/device charger

I am doing my best to make a portable charger. Here is the link with the schematic of the circuit I am working on:Voltage regulator question .I was told that the 9 V battery I was using didn't have ...
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1answer
76 views

Circuit and schematics - grounding diode

I've never seen such connection before and I was wondering why the diode is grounded in that configuration.
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66 views

Voltage regulator question

I have made a portable device charger with a 5 volt voltage regulator(7805-TO220 package),a 9 volt battery and a few capacitors.The problem is,when I connect the charger to a certain device(whose ...
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1answer
34 views

How does this logic level converter on the Adafruit HUZZAH work

I am busy with a project where I am connecting a 5V(Amtel ATMega328) MCU to an 3V(ESP8266) via the serial port. Obviously I need some logic levels converted. I looked at the schematics of several ...
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2answers
80 views

How PN junction diode is used as temperature sensor [closed]

I know the operation of PN junction diode. But I wonder how they use it as a temperature sensor.
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1answer
33 views

Generalized transistor equation for Collector Current including the reverse saturtion current?

44I am referring to Millman's Integrated electronics and there I came across and equation $$ \begin{equation} (I_c) = -\alpha(I_E)+I_{Co}(1-\exp^{V_C/V_T}) -->eqn(5.6) \end{equation} $$ where $$ ...
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57 views

Isolating GPIO's using diodes

Schematic The arrows are GPIO's I want to be able to close multiple switches at once in any particular order in order to manipulate GPIO's manually. I could give each GPIO its own resistor, but when ...
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1answer
63 views

Diode question help here please

We have the circuit in the figure.I have to find the currents in the diodes and in the resistances R1 and R2. The diodes are real and Vd=0.7 V Awesome. Here is the original figure I have drawn ...
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1answer
98 views

What are these white spots on my solar panel [on hold]

I purchased a 5W solar panel from Sparkfun, and after using it outside for about a week, these large white spots started showing up. Here's a closeup: The solar panel is not being back-fed thanks ...
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0answers
45 views

Diode circuit is this correct

We have the circuit in the figure.I have to find Vo when Vi=30sin2πt I think that this is Vo when Vi=30sint2πt..Is this correct? Vo max is 10 Volt and Vo min is =Vi-5/3=(-30-5)/3=-11.6
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2answers
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Which assumption to consider first when there is more than one diode

In this question we can easily find the solution,but here(in this particular question) we can make out the most forward bias voltage and solve it, but in some circuits where we cannot identify ...
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71 views

How can I perform power source switching using a P-channel MOSFET?

I am trying to build a power source switching circuit for an Arduino-based GPS tracking device/application. One power source is a solar-cell (rated at 1.5W and 6V) and the other is a 3.7V lithium-ion ...
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1answer
100 views

Analyzing resistive circuit with ideal diodes

The circuit is this: The diodes are ideal. The solution for this question is D1 OFF and D2 ON, and hence current \$I = 3mA\$. But when I assume that both D1 and D2 are OFF, I am not able to prove ...
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1answer
82 views

Need help understanding simple diode clamp & voltage divide combination

I am trying to understand Art of Electronics 2nd Edition page 50. The bit that I don't understand is that the impedance looking into the divider has to be small compared with with R (see first ...
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89 views

a question on diode

the diodes are ideal .assuming the diode up as off and the diode down as on, the voltage vab comes as 0 . am i right?
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3answers
71 views

what happens when both anode and cathode voltages are same for a diode?

In a circuit if the ideal diode has both the cathode and anode voltage same , will it conduct or not? and similarly in a constant drop model if the voltage drop is exactly equal to 0.7 will it conduct ...
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20 views

Two-tone alarm issues

I'm working on an inclass project, for a two-tone alarm circuit. The 3V source represents two AA batteries. We've implemented this successfully on a breadboard. The IC used for the Inverted Schmitt ...
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1answer
62 views

How can i connect 9 7segments to a 3x4 keypad using only diodes making each 7segment displays only one number? [closed]

I want to make each button in the keypad to display one number using only diodes without using any decoders or ic. thanks in advance
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1answer
40 views

replacing diode array with discrete components

I have a little proyect where I will be using a SIM908 GSM module. in the SIM908 Hardware Guide it states that a diode array should be used to protect the SIM lines, recomending an ESDA6V1W5 ...
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1answer
34 views

Signal Detector (Field Strength Meter)

Hello I have attached a circuit of a Field Strength Meter that I came up with, my target frequency is around 500Mhz. I was wondering if a design like this will even be able to tune to 500Mhz. I am ...
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52 views

for which frequency level, shottky diode become more efficient for rectifiers?

i need to justify why i chose shottky diodes instead of silicon diodes for rectifying a 50kHz AC signal. On the internet i only find qualitative comparisons and i don't find this information. Thank ...
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1answer
27 views

Dimension of charge pump diode

I am using a L6470H as step motor driver. The data sheet told me to use the following configuration for voltage pumping: simulate this circuit – Schematic created using CircuitLab (Value ...
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25 views

Wave Digital Filter (Basic)

DOWN wave is the reflection, am I right? And is D considered as reflection-free (rf) in dtyeh's illustration? Because the root of the tree is D, there should not be rf on D and since there is no rf ...
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3answers
689 views

Is there a fundamental limitation on how rapidly (with voltage) can a diode ’switch’ ? If so, can you pinpoint its origin?

Is there a fundamental limitation on how rapidly (with voltage) can a diode ’switch’ ? If so, can you pinpoint its origin? The diode here is a 1N914
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2answers
107 views

Help me to understand the simplest voltage multiplers

I attached a picture of the Villard circuit bellow. I can't seem to understand why the capacitor stays charged-up. Since I = CdV/dt, a capacitor finishes being charged at the crests of the voltage ...
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2answers
84 views

Correct diode for this application

I have this circuit on a breadboard and it works exactly as I expect. If you put in -5V you get out +5V, if you put in 0V, you get out -5V, and if you put in +5V you get out 0V. The problem I'm ...
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287 views

What's the idea behind this, assuming it is ideal?

The circuit is a biased push-pull. The diodes keep the input signal above and below the input signal so it is always conducting. The problem is that I don't see why one of the two transistors would ...
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Help identify round diodes - need a replacements [migrated]

Few diodes died in three phase rectifier circuit on a motorbike. I can't find any suitable replacement online since I can't understand what kind of packaging is it. They round like a round pill. 7mm ...
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381 views

How to convert low voltage (< 0.4V) AC to DC

I've made a mini generator for a mini wind turbine. An oscilloscope voltage measurement shows a +0.4/-0.4 V sinusoidal AC current. I'd like to convert it into DC, in order to put a charge and detect ...
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2answers
80 views

Effect of LEDs in series instead of parallel with resistors

So I have two LEDs with a Forward Voltage rating of 2.65V each. Would I be okay in hooking them up to a power supply of 5v in series rather than in parallel with resistors? I'm asking mostly because ...
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1answer
160 views

Use a diode or a MOSFET with a backup battery?

I'm running off-grid 12V domestic electricity, with solar panels and leisure batteries. The charge controller sits between the batteries and the load, and occasionally, briefly, cuts out the load ...
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1answer
44 views

Why does the l293 have a higher current than the l293D?

I know the "D" mean diode, so it has a built in diode. I would not think that the addition of a built in diode would lower the current rating by that much. Also, if I were to use a l293, where would ...
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4answers
297 views

Why does temperature modify the characteristics of a diode?

Everyone knows that temperature affects every semiconductor device you can think of, and diodes are no exception. From the below graph, we can see that the temperature has marked effects on pn ...
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The equivalent circuit for \$V_{in} > 0\$ with the amplitude of \$V_{out}\$

I have a strong mathematical background and I am trying to improve my (poor) physics. If this is not the right stackexchange forum for this subject, I would be grateful if you could refer me to the ...
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1answer
34 views

Computing capacitor voltage through series connected diode

I have been trying to analyze this circuit and calculate the maximum voltage across the capacitor. Here is the diagram: And, here are the graphs for various inputs and the resultant outputs: ...
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3answers
149 views

Why the diode has higher impact on dc characteristics than ac?

Consider this circuit which consists of a DC bias and an AC source connected with a diode and resistor: Source: Boylestad and Nashley book 11th ed. Using superposition theorem the circuit was ...
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43 views

Single Transistor DC TO AC Circut

I have a question that may be rather difficult to ask and format however I will try. Now I am very new to electronics in general but in my spare time I play around with them a little bit. I have ...
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3answers
136 views

Why are two diodes used here?

I'm following the wiring diagram for a digitech fs3x guitar pedal footswitch. For the third SPST switch, it's wired from the other two switches connected by 2 diodes, both in the same direction. Can ...
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100 views

Modifiying SparkFun Uh-Oh Batt. Indicator - TL431 Regulator Diode Based

I'm trying to modify a simple SparkFun Uh-Oh Battery Level Indicator - KIT - 11087 https://www.sparkfun.com/products/11087 It can handle a maximum voltage of 12 or so volts, above that I believe it ...
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1answer
95 views

Do I really need a flyback diode when using a power mosfet?

I am using one of these IRF1404 Power Mosfet and looking at the datasheet I see that the continuous source current (in the Source-Drain ratings section) is rated at 202A!! I will be using it to drive ...
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Single sided capacitor discharge

What I am looking to do here is ,after current stops flowing through D1 , I want current for a few moments to operate the transistor . So this is the circuit , current charges up the capacitor and ...
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Why doesn't the depletion zone cover the entire diode?

When you form a PN junction you're basically closing a circuit so why don't the free electrons in the N and the holes in the P diffuse completely as they would in any other circuit?
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Thermal Runaway in Diodes

Datasheet for 1N5406 diode states "3.0 ampere operation at Ta = 75°C with no thermal runaway". What does this mean exactly? Can I place these in parallel to increase current capability?
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Power and Ground Clamp Diodes in CMOS IO Buffer

I have usually seen Power & Ground Clamp diodes in CMOS structure as per attached figure. They are protection diodes. But I have few doubts :- 1.can someone explain in what situations they are ...