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Questions tagged [diodes]

Diodes are semiconductor components made from a P-type (or metal in Schottky diodes) and N-type material (usually silicon, but germanium, selenium, and gallium arsenide can also be used), that allow current to flow in one direction only.

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How does CAN transceivers output CANH=3.5V and CANL=1.5V? [duplicate]

This is a questions that has been asked but did not find a clear answer. How it is the 3.5V achieved on CAN_H? Assuming there is 0.5V voltage drop on the internal diode, 0.1V on the internal MOSFET ...
Florin Adrian's user avatar
-1 votes
0 answers
33 views

Need Help Wiring Turn Signal Indicators [migrated]

So here's what I'm trying to do... I have a golf cart with a 12v LED headlight/park light/turn signal system. I wanted to add a left and right turn signal indicator in the dash because I always forget ...
Justin Walters's user avatar
0 votes
1 answer
55 views

LTspice sofware Zener diode model 3bdc missing [closed]

I cannot find any models for LTspice for Zener diode breakdown voltage of 3 V. I need Zener diode because I am trying to get simple voltage stabilizer and my load cannot handle more than 3 V. I cannot ...
hhsting's user avatar
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0 answers
51 views

Vending machine motor working [duplicate]

I am trying to fix a vending machine motor and trying to run it directly without a microcontroller to understand its working, but I am not able to get it working. The motor has 6 terminals: T1 and T2 ...
Shashank Kumar's user avatar
0 votes
1 answer
38 views

Keithley 2290-5 testing setup power diode in reverse bias [closed]

I have to analyse the I-V characteristics in reverse of a power diode. So I would do a setup test to ground the diode safely. Which documents or paper could I read? EDIT: I haven't the protection ...
SirU's user avatar
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0 answers
42 views

Questions regarding TVS-diodes and grounding

I am currently working with solutions to pass the ESD-requirements for EMC. I have used TVS (ESD)-diodes in the past to good result, but never really understood exactly why they work. Sadly, this is ...
sternis1's user avatar
1 vote
1 answer
52 views

Identify smd component ( p_j89 ck)

I have electronic board of level switch device. I have a problem in it a found an element it seems like a diode but I need its data sheet to find a replacement for it because it is short circuit in ...
Abdelrahman Esmat's user avatar
1 vote
1 answer
68 views

Did I draw my circuit diagram correctly for 2 MOSFETS and a solenoid?

My project consists of one 5 V solenoid (but uses 3.3 V), one voltage regulator (5 V to 3.3 V), one diode, two N-channel MOSFET transistors, and one 5 V LED strip, all controlled by a Raspberry Pi ...
alxzhu's user avatar
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0 votes
2 answers
54 views

How can I use a relay and diodes to reverse the polarity to a electromagnet?

I am trying to make a solenoid using a motor, relay, and 12-volt battery. I have everything working, but it only goes one way. I want it to reverse the polarity when the relay is open. Will it work if ...
Seymour Butz's user avatar
0 votes
2 answers
41 views

Identify single diode top marking A2, SOT23 (SOT23-3) package

I need to identify a diode (it may be a Schottky) single channel with top marking A2 in SOT23 (SOT23-3) package.
Areyou Who's user avatar
2 votes
1 answer
67 views

What does back-back mean in the context of TVS diodes?

I am making the schematic of a 24 V power supply regulator using the LM74900-Q1 IC. When selecting the TVS diodes, I found the following design suggestion in the datasheet of another IC (LM74800-Q1) ...
Luis J. Mora's user avatar
0 votes
1 answer
55 views

SMPS diode identification

It's marked T2D46 with a bar over the 46. It tests open both ways on a DMM diode test. I can't locate this with all of my google-fu powers or Octopart etc. EDIT: I've included a picture of the board ...
Roberto's user avatar
  • 125
0 votes
1 answer
50 views

Test that plug is wired correctly

I am looking to build a tester that is verifying that 12 VDC connectors are wired for the correct polarity. It will have a series of plugs for a wiring harness and a switch for each one with a red ...
Caddrawer's user avatar
0 votes
2 answers
108 views

Conduction of Thyristor and Diode

Consider the following circuit: Let \$ \phi \$ denote the angle for which the thyristor T1 is triggered, i want to know why when \$ \omega t = \theta \in (0, \phi) \$ T2 and D2 are conducting i see ...
Knowledge Seeker's user avatar
6 votes
5 answers
3k views

Series connection of diode and resistor. Why is there a constant voltage across the diode?

So I know that a diode can be described using the Shockley equation and after a certain voltage, the diode current begins to increase rapidly. The nominal 0.7 volts. I also know that this voltage ...
maxgrn27's user avatar
5 votes
3 answers
617 views

LED as a flyback for a 3V relay?

I have a 3VDC SPDT relay. I don't have a fly back diode but I do have an LED. Can I use the LED as a fly back diode if it's just a 3V relay? The relay is a HRS4H-S DC3V.
Zipho Lunika's user avatar
2 votes
1 answer
973 views

Should I use diodes to safely integrate two power supplies producing +15VDC and -15VDC?

I am using two identical Meanwell LRS-150-15 power supplies to produce +15VDC and -15VDC compared to ground. My ground is tied to earth. The setup with its connectors and nets is represented in the ...
Tommy95's user avatar
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0 votes
1 answer
64 views

Is this schematic for an LED power status drawn correctly?

I have a simple schematic drawn out in KiCAD for a single purple LED to light up when there is power running through to a array of 5050 RGB LEDs. The reason I'm not sure my schematic will work is ...
happycamper1221's user avatar
1 vote
1 answer
37 views

Bias condition of parallel silicon PN diode circuit

In the following question, D1 is operated in forward bias condition. Then the voltage across D1 is 0.7 V. Then the voltage across D2 also 0.7 V; but no current flows through D2. Then what is the ...
madhuranga ishaka's user avatar
2 votes
2 answers
922 views

Yellow components on light intensity module PCB

Can anyone tell me what the yellow components on this PCB are please? At first I thought diode - they measure 0.7 V but then 1.7V when measuring reverse-bias. Then I thought capacitor - but the both ...
dntknwnthng's user avatar
1 vote
0 answers
47 views

Junction diode "built-in" voltages

When a PN Junction terminal are left open-circuited, the voltage measured between then is zero. The Junction voltage Vo does not appears. Because similar built in voltages arise at metal semiconductor ...
Abdus Salam Akand's user avatar
1 vote
6 answers
283 views

What happens if I feed a diode (in the forward direction) from a DC current source?

Can I forward bias the diode using a a DC current source? Is there a minimum forward bias current that switches on the diode? How would the voltage on the branch be impacted by the diode? Suppose the ...
Init_Eng's user avatar
1 vote
1 answer
59 views

ID & Possible Substitutions for Blown Old Vishay SMD Component

can anyone please identify the component "VD20" (Marked SJ 47A with Vishay logo) pictured in the attached images. There are 8 of these similarly marked components still intact on the board. ...
YoungDiode's user avatar
1 vote
1 answer
45 views

Substituting for 1N34A diode to change range of microwave detector

In connection to an earlier question, this DIY device for detecting "mini radio" EMF seemed like it might work to detect microwaves generally, assuming diodes exist to replace the 1N34A ...
daniel's user avatar
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-1 votes
2 answers
47 views

Does the three-pin diode have a half current? [closed]

I need a 30 amp diode for the battery backup. I have used an MBRF30100CT diode. But I don't know the diode current is 30 amps or half of it is 15 amps.
sn01's user avatar
  • 1
1 vote
1 answer
71 views

Can off-the-shelf "Ideal Diode" modules be used in Diode Or-ing circuit for power redundancy systems?

I'm designing a 12V UPS for my router and modem, and have come across common diode or-ing circuits such as this one: (source: Static and Dynamic Behavior of the MAX40200 in a Diode ORing Application) ...
QuickishFM's user avatar
1 vote
2 answers
157 views

Why are 2 diodes needed instead of 1 when diode-ORing two power supplies?

I see many circuits online of dual power supplies connected in parallel through output diodes on their outputs, to provide redundancy in case the main one fails. Usually the primary supply is an AC-DC ...
QuickishFM's user avatar
1 vote
3 answers
75 views

Full wave bridge rectifier with Pi or T filter simulation won't converge

I'm designing a full wave bridge rectifier and want to compare a pi filter and T filter after the rectification. I intend to add a transformer at the input and a buck-boost converter on the output. ...
BTB18's user avatar
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2 votes
1 answer
59 views

Help identifying SMD diode

I'm retrofitting an 8BitDo Pro 2 controller for a project, and in doing so I melted one of the components on the board. I'm looking into ordering another one, as it was the same as another component ...
J_R's user avatar
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0 votes
2 answers
64 views

Am I using the Zener Diode Correctly?

I am building a custom atmeta328 board that I want to make sure handles the bootloader properly. I have DTR from my FTDI chip going through a .1uF capacitor to the Reset pin on the MCU. I also have ...
Kevin McQuown's user avatar
0 votes
0 answers
13 views

Adding an indicator LED to show a 72v contactor is closed [migrated]

I'm upgrading the battery on my electric boat. Currently I have a 72v 100ah LifePO4 battery. I have a solenoid between the controller and the battery. That solenoid is attached to the ignition key. ...
Daniel Morris's user avatar
0 votes
2 answers
54 views

In a simple series circuit, one with a diode, if I were to calculate the current via KVL, then that current MUST satisfy the diode equation?

In a simple series circuit, one with a diode (given its voltage), if I were to calculate the current via KVL, then that current MUST satisfy the diode equation as well? Were that the case, then I ...
Jack's user avatar
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0 votes
1 answer
53 views

What is a precise definiton of "cut-in" voltage as applied to diodes?

What is the "cut-in" voltage or knee voltage of a diode or transistor? In a lot of books I read that the cut-in or knee voltage of a diode (or transistor) is when the diode starts conducting ...
Qwe Boss's user avatar
1 vote
1 answer
46 views

Fast high-voltage diode stack (for snubber circuit)

I have a specific application in mind, but a more general question regarding diode stacks. System overview: We have a constant-current source which is driving a constant current through a magnet. We ...
PulsePowerFTW's user avatar
7 votes
6 answers
1k views

Diode clipping question on output of opamp

I have been trying to implement a basic hard-clipping circuit for a distortion guitar pedal, based on two simple diodes, but somehow I can't get it to work as it is supposed to be. The basic design is ...
miguelfuzz's user avatar
1 vote
1 answer
111 views

IRF520 MOSFET won't close when voltage is applied

I'm trying to make a simple MOSFET switch but something weird is happening: no matter the gate input, the LED stays on. Ultimately this circuit is meant to drive a stepper motor but I'm using an LED ...
Pedro Costa's user avatar
0 votes
1 answer
77 views

Bridge rectifier vs full wave rectifier with two diodes

I've been wondering why bridge rectifier provides better significance and is mostly taught everywhere in universities rather than a similar circuit that uses two diodes in parallel instead of four. ...
Adiji007's user avatar
4 votes
1 answer
397 views

Is a diode really necessary when exposing USB VBUS as a pin on a dev board?

Hobbyist dev boards are typically powered by USB and the GND and VBUS pins of the USB connector are usually broken out as pins on the board (so, that one can power additional devices connected to ...
George Hawkins's user avatar
1 vote
1 answer
28 views

STM32G030K6 24V on input pins with internal protection diodes

I have 24VDC signal and I want STM32G030K6 MCU to detect it (state low/high). I know this MCU has internal diodes on some pins, connected from inputs to VDD and max positive injected current is 5mA. ...
Mietek's user avatar
  • 11
0 votes
2 answers
108 views

Problem with a diode-circuit design

I have a problem with a diode circuit design problem: [Source: Microelectronic Circuit Analysis and Design.] Basically a circuit where the current through the Si diode is linear if: \begin{equation} ...
Richard Kingston's user avatar
0 votes
0 answers
35 views

Effect of coupling factor in flyback converter relative to rectifying diode

I'm simulating a CCM flyback converter on ltspice, and I need some help in understanding the results when I decreased the coupling factor from 1 to 0.96. When K=1, the voltage appearing across the ...
Hamza Harbi's user avatar
-1 votes
2 answers
241 views

How can I build a full wave rectifier with a grounded load without the use of a transformer?

I replaced the transformer with an AC source. If I only ground the load and not the AC source, it works. I have to ground the AC source due to the use of function generator in practical purposes. It ...
user avatar
0 votes
1 answer
79 views

Help with vehicle killswitch design

I am relatively new to electronics/electrical, and want to design a killswitch for my car, since it is easy to steal. I have created the design shown below, which is intended to function like so: if ...
Alex's user avatar
  • 1
2 votes
2 answers
121 views

Why do the diodes make a huge difference in an RC sinewave generator circuit?

In the following LTspice simulation of a sine wave generator circuit, it cannot oscillate without D1 and D2, but as long as D1 and D2 are added, (1+R5/R6)=1.5 can also oscillate (as shown in the ...
谢一鸣's user avatar
4 votes
4 answers
258 views

Analysis of the below op-amp circuit and its waveform

What will be the output voltage and capacitor voltage waveform for this problem? [The approach I tried --> When the diode is ON, the negative feedback is complete and voltage of inverting terminal ...
Gawdfather47's user avatar
2 votes
1 answer
428 views

What is this part marked WH5 33?

What is this part and what is its part number? I can't find a part with the code WH5 33.
Ahmad Abd El Maksoud's user avatar
0 votes
0 answers
16 views

Lightning cable bundle testing

I have two wires going to a solenoid. Power and ground. The wires are in in shielded bundle. When we apply a induced lighting voltage let's say waveform 5A, will both wires will be impacted equally? I ...
Navin's user avatar
  • 1
0 votes
1 answer
57 views

Finding Is, Id of a Diode in reverse-bias mode

Excuse me, sir, I'm currently finishing my lab experiment report but I got stuck finding Id and Is of a Diode in reverse-biased mode. Here is the question: Vin is in the range of 0V to 18V with the ...
CÔNG NGUYỄN DUY's user avatar
3 votes
0 answers
55 views

Output diode selection to make 50Hz stick welder DC

I am fixing up a stick welder with a max output current of 240 A. DC welding has advantages in some jobs so I want to design/build a rectifier. My measured open circuit voltage is about 50 VAC, it ...
Autistic's user avatar
  • 14.8k
0 votes
0 answers
69 views

How can I connect multiple 8V AC inputs into one earthed probe?

I am trying to design circuitry to connect 4 separate float-less water level controllers into one probe. Each unit needs to confirm that there is water in the tank and if not, will shut down. Not all ...
Minnikin's user avatar

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