Questions tagged [reverse-polarity]

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3answers
76 views

Why does my ceiling fan spin the wrong way?

My ceiling fan blows are at the ceiling (uselessly). At first, I wondered whether I could fix it by maybe removing it and switching some kind of polarity. But is there a polarity? Aren't the ...
3
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5answers
7k views

maximum reverse voltage applied to a resistor-LED configuration

Consider the simple circuit below: simulate this circuit – Schematic created using CircuitLab LED datasheet: link Does the applying of a reversed 36 volts to this circuit damage the LED? ...
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1answer
51 views

Purpose of this Zener diode (reverse protection)

I have the below MOSFET circuit: Zener diode - Datasheet N-channel MOSFET - Datasheet I want to understand what is the purpose of the Zener diode D5202 and at what conditions does the Zener diode ...
2
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2answers
46 views

Invert polarity with DPDT relay

I'm trying to wire a 12v DC motor to a DPDT switch so I can control the spin direction (by inverting the polarity) it uses two digital pins, one of them to set the direction of the motor and another ...
2
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0answers
35 views

Automotive reverse current and transient protection

Adding reverse polarity and reverse current protection to an automotive circuit seems a bit challenging, especially when driving loads in the 10A range (e.g. seat heater). Diodes on the power line ...
4
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1answer
59 views

3 Phase motor changing rotation on startup intermittently

I have a total of three 3-phase floating fountain aerators. Last year they functioned properly. This year when I connected them, two of them were running in reverse and 1 was running forward. All ...
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2answers
2k views

Reverse Polarity & Load Dump Protection (TVS)

Based on this and other material I’ve read, I should have a diode for reverse polarity protection and a TVS for load-dump protection in an automotive circuit. I have prototyped the circuit and its ...
2
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2answers
2k views

What will reverse polarity in an Energizer AAA, unpowered, dead battery, circuit?

Circuit is a three-LED reading lamp. Batteries were left in for "a long time, but it worked last time I used it" according to Mom. Unknown if switch was 0 or 1. All three batteries were inserted ...
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1answer
112 views

Charging and discharging 18650 batteries with TP4056 modules via their power output terminals

I'm having those fancy ESP boards that come with a battery input pins/holders that can be connected to a battery to make them portable. They also have a dedicated USB port for charging/sketch uploads. ...
1
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1answer
128 views

How to wire an old single phase AC brushed motor to be reversable

I have searched several forums and found a lot of interesting stuff, but nothing yet that really applies to my situation. I have an old Westinghouse FH motor 1 1/2HP single phase brushed AC motor. ...
0
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1answer
549 views

Have I fried the transistor in this circuit?

It was a germanium PNP transistor. I might've pressed the button too. I saw transistors used as capacitors that were connected like this, but they weren't germaniums. What current (if any) has flown ...
0
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1answer
29 views

Do PMOS Reverse Input protect on ORed power rail

As the title says, I have a power mux IC and two power inputs. I need them to be protected from reverse voltage input. The power mux i have already comes with a reverse voltage input protection but i ...
2
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0answers
43 views

Protect voltage level translator from reverse voltage input

I have a circuit that can interface with an external signal or power. And Those signal lines must be translated to a 3.3v level (and vice versa) because that what the circuit uses. And I would like to ...
0
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1answer
56 views

How to PWM a load regardless of the direction of current?

I'm helping a student at our art academy with an interesting project. She is building an array of peltier elements (let's say 25 to start with). She wants to control them individually using PWM and be ...
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1answer
55 views

Can fried op amp still work?

I had a strange adventure today. I was repairing a mixer and plugged the connectors reverse when mounting it together. When i turned the power on it was behaving strange, and i started to smell fried ...
1
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1answer
34 views

DW01 for Lithium Non-Rechargeable Battery Protection

I'm thinking of using the DW01 IC to make a simple non rechargeable battery protection (over current, short circuit, over discharge). The sample schematic requires two Power fets, one to control ...
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2answers
74 views

Reverse Polarity Protection Circuit with P MOSFET and Zener

I have been trying to understand the operation of the following polarity protection circuit (Diagram doesn't show the internal body diode of MOSFET): simulate this circuit – Schematic created ...
15
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2answers
3k views

Do serially connected diodes share equal reverse voltage?

If I place three cheap 200 V rated diodes across a 500 V supply instead of one expensive diode, is the system guarantied to work correctly? My worry is the situation at which two of the diodes share ...
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1answer
30 views

Smart High-Side Switch - Reverse Battery Protection Feature

I'm designing a switch for an automotive application and found this IC BTS428 that supposedly solves all my problems. Following the manual, i came with the following circuit (LATCH PUSHBUTTON). ...
13
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3answers
8k views

Does an electrolytic capacitor degrade each time it receives reverse voltage?

I know that I mustn't connect an electrolytic capacitor reversely. It will explode if I apply the reverse voltage long enough. But, what happens if the reverse voltage is applied for a short time? ...
1
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2answers
46 views

MOSFET Gate-Source voltage in protection circuit

I'm creating board which is supposed to withstand OV/UV and reverse voltage. I've chosen LTC4365CTS8#TRMPBF(datasheet) IC to deal with this problem. In reference schematic for 24V input they are using ...
0
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1answer
80 views

Can I use a p channel mosfet as reverse polarity protection but still charge a Li-Ion battery?

I want to design the following reverse protection circuit: The gist of the design is that I want to run a SIM808 chip from a 3.7V battery. I understand that the circuit as such will protect if the ...
0
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1answer
53 views

How to wire a PPTC polyswitch + blown indicator LED to protect a bi-directional DC motor from stalling?

I have the following setup and it works well as is, except that I would like to protect the 12V DC motors (Reverse High Torque Permanent Magnet 12V DC motor) with a PPTC polyswitch + a LED to indicate ...
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0answers
22 views

SIZING steps and Interpreting Mosfet datasheet

After reading those Interpreting Maximum Power of a MOSFET from the datasheet How to interpret Vgs(th) min/max in a MOSFET datasheet? https://www.infineon.com/dgdl/Infineon-...
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0answers
27 views

DC to LIPO charging module reverse Feedback

I want to be able to use DC 12v to power my circuit but also have ability to have it powered by a battery. The thought I have is: * A on/off switch allows battery output to be switched on/off while ...
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0answers
55 views

Mosfet control Rds on , and Vgs

I want to know how to calculate Vgs , assuming load current Id is constant , Vd = voltage of battery is constant , and fet is operating in thermal stability region , so there is no thermal runnawy , ...
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1answer
69 views

Reverse Polarity in rush Protection 2 p fet parallel

after reading those links : Reverse-polarity protection P-channel MOSFET Optimal method for multiple MOSFETs for LED driving with a shared power rail Parallel MOSFETs and this pdf : ...
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0answers
33 views

how to proteus simulation inrush current

i've a reverse polarity protection , i want to check inrush current simulation , but i don't know how . i read this , but i tried but doesnt work How to plot voltage vs current graph on Proteus ...
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1answer
55 views

I have a 3D printer and I cant figure out how to digitally reverse the x and y axes [closed]

There are red yellow gray and green wires, in that order.
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4answers
112 views

Reverse polarity protection on 5-12V input and output

Can someone help me with reverse polarity protection on 5-12V input and output using a using a P-Channel MOSFET? How can I calculate which MOSFET, resistor, zener diode I have to use? I use a 5V 10A ...
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1answer
60 views

Zener diode in parallel with both the input terminals and the output terminals

"There is a zener diode in parallel with both the input terminals and the output terminals. Combined with the fuse these should help in reverse polarity situations (it should blow the fuse before ...
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0answers
23 views

p mosfet calculations reverse polarity for high power ( 48 V , 30 A )

i want to make reverse polarity protection for input 48 voltage , load 30 Ampere 2 dc buck converters. i was searching many solutions like diodes , but i wanna make it with p fet , so i came across ...
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1answer
41 views

Reverse Polarity Protection relay calculation

i want to make reverse polarity protection without voltage drop ,i was searching and i found this https://www.edn.com/design/analog/4368527/Simple-reverse-polarity-protection-circuit-has-no-voltage-...
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2answers
115 views

BLDC/BLAC controller motor voltage reverse protection

I am currently designing a BLDC controller and keep running into a power safety issue: I have added a smart diode reverse protection controller to my design with its transistor between the fuse and ...
1
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1answer
84 views

I swapped +5V and ground on a chip, how to know if the chip is dead?

Well, I accidentally connected ground to the +5V pin and vice-versa on a (W65C22), I don't know how to be sure that I didn't burn the chip. One thing I was noticing is that when the cables were ...
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0answers
49 views

How to prevent reverse current/voltage on a sense line?

I'm designing a rocket launch controller, that incorporates an Arduino to provide a safer and more controlled launch. Original rocket launch controllers used to use an incandescent light bulb and a ...
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2answers
506 views

Power supply 0-30 volt reverse voltage protection

I have made a bench power supply that can erogate 0-30 volt and 0-2 A. Now, how can i protect my bench power supply from reversed voltage applied to it's output? Typical p or n mosfet circuit dosent ...
6
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2answers
442 views

Reverse voltage protection for Analog Devices’ family of protection controllers

After going through several datasheets for devices from "Analog Devices’ family of high voltage surge stoppers, overvoltage protection, overcurrent protection, and circuit breaker ICs", I found that ...
1
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1answer
321 views

Output of 4.8V due to reverse polarity series schottky diode?

I was reading through the Data Sheet for the Photon, an IoT dev board: https://docs.particle.io/datasheets/photon-datasheet/ and under the Power section it says: When the Photon is powered via the ...
5
votes
1answer
945 views

Replacing two LEDs with a 2-pin, bicolor LED, using a circuit that reverses polarity based on two inputs

I'm working with a commercially available circuit that can optionally be configured to disable its internal LEDs and use two external LEDs. This post discusses the use of external LEDs. One LED or the ...
0
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1answer
63 views

Forward Voltage VF Max 1V does this mean that the full wave w10 bridge rectifier can only allow 1 volts via it

I want to use a full-wave bridge rectifier. My circuit needs 2 amps of current and operates at 12volts (12V @ 2A). I found this https://www.tanotis.com/products/vishay-2w01g-e4-51-bridge-rectifier-...
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0answers
78 views

Reverse Voltage Protection with feedback circuit

I would like to understand on the feedback transistor circuit in the given reverse voltage protection circuit. Voltage Input: 7V to 32V.
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2answers
390 views

Using diodes for reverse polarity protection

I want to protect my circuit against reverse polarity, by simply adding two diodes in parallel between the + and - input cables. So if the polarity is reversed, the current will go through those ...
3
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1answer
136 views

Pull-up resistor in parallel with Schottky barrier diode

I was looking at the Zynq-7000 SOC startup sequence designed in the Zynq Evaluation and Development board (ZedBoard), which requires specific voltage level regulation sequence (1.0V, 1.8V, 3.3V and 1....
0
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1answer
317 views

Effect of Reversed Phase Polarity on Active & Reactive Power of 3-Phase System?

I am trying to investigate the Power/Energy of 3-Phase System under Different Faults. I have a Three Phase Source and Load, Load is balanced i.e same phase angle and current (Phase-Neutral V = 230 ...
3
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4answers
1k views

How to avoid voltage drop when using full bridge rectifier as reverse polarity protection

I found a couple of old bridge rectifiers. After reading some docs and tutorials about reverse polarity protection decided to give them a try. The problem is nobody offered a solution against the ...
2
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2answers
366 views

Reverse-polarity protection P-channel MOSFET

There are many ways one can build a reverse-polarity protection circuit. Using diodes, Shottky diodes, n-MOS in the return path and using a P-channel MOSFET on the positive side of the circuit. My ...
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0answers
34 views

voltage polarity exchange and reverse protection circuit

Ordered voltage polarity exchange and reverse protection boards from China but they never arrived. Trying to recreate a circuit diagram from a picture and need help. Found this article. https://www....
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2answers
336 views

How to protect input against both ESD and reverse polarity?

I need to protect an external input on a device against both reverse polarity and ESD (IEC61000-4-2 +-8kV). The normal input is +5V dc at 100-200mA; the reversed input could be -5V and that should be ...
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3answers
191 views

Why does reverse supply polarity damage the ICs? [duplicate]

Assuming you need for example an OR gate for your circuit project, you can use a 4071 IC or simply use two transistors as shown below: But I wonder why the ICs are very sensitive to reverse supply ...