Questions tagged [reverse-polarity]

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Over voltage and reverse polarity protection

I was trying to make an over voltage and reverse polarity protection circuit and create a PCB that I can easily use in some of my projects. My level of electronics it's not so good, and that's why I'm ...
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1answer
54 views

Reversed universal universal motor sparks and shows arcing even though brushes are completely perpendicular to the commutator

I need to reverse the rotation of the universal motor in question so I swapped the wires leading to the brushes and that successfully reversed the rotation, but now the commutator is arcing and is ...
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44 views

Oscillating DC polarity reversal for LED lights

I have a cheap battery powered LED light strand that had a corroded and non-functional control board. The LEDs looks like they are rated for about 3.3V with up to 20mA per bulb, and the original ...
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1answer
34 views

Track loader actuators: Provide reverse capability for two DC motors, on board snow blower attachment

I bought a 7 ft wide John Deere snowblower and want to use it on an ASV track loader. The two companies use different strategies for running electrical units on attachments. This requires wiring up ...
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1answer
43 views

Protecting battery and USB inputs from each other

I have this circuit, which I expect will protect my primary cell from USB voltage and my USB port from being powered by the battery. My logic is; D2 will stop anything flowing out of the USB port ...
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1answer
77 views

Using h-bridge with LED fairy lights

I have a string of LED fairy lights (5v) that when I connect to power, only half of them light up. If I reverse the polarity, the other half light up. It’s my understanding that I need a h-bridge to ...
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0answers
50 views

The Best Place for the Reverse Polarity Protection Diode

I have several RS485 devices. All of them are connected together and power by a 12V power supply. Each device has its own 5V voltage regulator. I want to use diodes for each of them to protect aginst ...
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1answer
49 views

Is this reversed P-MOS next to the battery for some other purpose?

I was handed a schematic with this P-FET next to the battery. My experience tells me that this would not provide any reverse polarity protection (which at a glance it what I thought it was for), but I ...
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0answers
52 views

Reverse current protection

I design a wearable, battery-powered device with a watertight enclosure. It will have a waterproof USB connector for battery charging. Here is a schematic. J2 is the USB connector, MCP73831 is the ...
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0answers
58 views

Reverse Polarity Protection p-channel mosfet

I am trying to design a basic reverse-polarity protection circuit using LTspice but I am not sure what values to use. The input voltage is 12 V, 100 ohms resistor and a 10 V Zener diode. What is the ...
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0answers
51 views

Reverse polarity protection with a MOSFET, am I doing it right?

I'm creating a simple LiPo charger and I would like to add a reverse polarity function to the module. The source voltage is 4.2V, the maximum current draw is 2A. Is this schematic correct? The MOSFET ...
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1answer
66 views

Reverse polarity protection on AD623 inputs used to measure low voltages on a sense resistor

This circuit used to measure low voltages on a sense resistor is part of my current meter in arduino that measures currents from 0.005ma to 5A. I configure the gain of the instrumentation amplifier ...
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1answer
68 views

Op-amp selection for reverse polarity protection on an Arduino voltmeter

I made an accurate voltmeter using an Arduino Nano as the microcontroller. What I want now is to add a reverse polarity protection using an op-amp with a gain of 1 without changing the actual accuracy ...
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1answer
31 views

Value of R in reverse voltage protection circuit based on PMOS

How do I choose the value of R2 in this circuit? (V = 12V, I = 2A) For the PMOS I am using SI2323DDS-T1-GE3 (Datasheet), is it to ok to use this PMOS (Maximum Power Dissipation=1.7W)? For the Zener ...
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1answer
99 views

How to protect the ADC GPIO PIN [Battery monitor] from reverse polarity?

I have a circuit which uses a battery boost converter to power the MCU. I use the ADC on the MCU to measure the actual battery voltage to display how much charge is left in the battery. The power ...
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1answer
96 views

Reverse-Current Protection with p-Channel MOSFET

I'm encountering an issue where reverse voltage/current on an output pin of an IC is backdriving into the power rail of a board. I would like to add reverse voltage/current protection to the circuit. ...
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1answer
33 views

Protection Diode Position on Regulators

Just a quick question regarding reverse polarity diodes with respect to linear voltage regulators. I saw some professional designs putting diodes on the output side of the regulator which confuses me ...
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1answer
48 views

Is reverse polarity protection required for the ZXTR2005Z regulator?

I am trying to figure out whether reverse polarity protection is required for the ZXTR2005Z regulator. On the one hand, the datasheet is "suspiciously" explicit that the input voltage must ...
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0answers
62 views

Reverse Polarity Question

everyone. I have a really simple power input network like so: The SMPS will power analog devices with +12V and the regulator will regulate the rest downstream to power digital circuitry with +5V. ...
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1answer
67 views

RS485 USB converter driver polarity

I have an RS485 USB converter connected with a temperature controller in the controller's datasheet it says that the 12 is (+) and 11 is (-) and in my USB converter there is A and B Am not sure the D+...
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63 views

4 6v batteries, with one connected wrong way round?

Today i was working on a machine with 4 6v batteries connected in series. It was in a building that was very dark and the batteries were covered in dirt and i briefly accidently fitted one of the ...
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0answers
756 views

Wiring Diagram Help - 6v 'Power-Wheels' Ride-On Upgrade

Hello, I have a 6v Ride On toy car that I want to upgrade to 12v without upgrading the entire electrical system as it is only design for 6v. My issue? I'm not in the electrical trade and i'm trying to ...
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68 views

Want to reverse AC Motor direction - need help

I have this old Westinghouse motor it turns clockwise and I need counter clockwise. It has 3 leads at a junction on the rear, 2 line and 1 middle lead labeled 0. Anyone know how to help? It is a 110v ...
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3answers
93 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 ...
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1answer
57 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 ...
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2answers
62 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 ...
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0answers
59 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 ...
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1answer
97 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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1answer
38 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 ...
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0answers
47 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 ...
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1answer
61 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
63 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 ...
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1answer
96 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
271 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 ...
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1answer
38 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). ...
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1answer
396 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. ...
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2answers
58 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 ...
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1answer
161 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 ...
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1answer
85 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
26 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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28 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
88 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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71 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
117 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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1answer
60 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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1answer
66 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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4answers
316 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

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
228 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 ...
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1answer
100 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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