An application field of electronics that requires high reliability and fail-safe systems. Application can vary widely in temperature ranges and a wide voltage range, typically 12v (or 24v) while off and higher when on.

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1answer
63 views

How does wireless mobile charging work in BMW 7 series car?

I've seen a video in which the presenter just keeps the phone in some small chamber and closes it for automatic charging of smartphone.
0
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1answer
36 views

Mysterious Noise Issue in Automotive Ignition Coil Application, Arduino

I'm building a circuit to count RPM based on watching the negative pole of the primary coil in an old automotive ignition coil. I had no illusions this would be easy, but here I am stuck even though I ...
0
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1answer
65 views

What is the correct way to hook up a second battery and solar panel to a vehicle? [closed]

I'm looking to install an aux battery in my van and hook it up to a small solar array ( 200w ). I would also like to be able to charge the second battery from the alternator when the van is running. I'...
0
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1answer
97 views

How can CAN transceivers ouput CANH=3.5V and CANL=1.5V?

When sending a dominant bit (0bit) on the CAN bus, I understand that CAN transceivers output CANH=3.5V and CANL=1.5V. But when looking at the schematics of a CAN transceiver, I do not understand how ...
0
votes
1answer
48 views

Reading the closing of 12 volt circuit over RS232

Car trouble. I suspect the fuel injector circuit. I am trying to construct a com port reader that will place a timestamp into a log on the closing the 12v fuel injector circuit. The fuel injector ...
0
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2answers
66 views

What type of connector / terminal end is this?

This wire comes off a automotive multi-pin relay block/connector housing. Requesting help to identify what type/name of connector it is. -Thanks
0
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0answers
6 views

Power to seperate starter switch only when motor isn't running [migrated]

I need a circuit to disengage power to the start switch which is seperate from key switch when engine has started so there is no chance of accidentally engaging the starter with the already operating ...
1
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3answers
87 views

Detecting a break in continuity where no voltage drop occurs

I have a solar charger on a vehicle which I need to protect: Schematic is down there... The charger connects to the main battery, and the solar panel, but the manual specifically states that you MUST ...
0
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1answer
65 views

Will my car's AM/FM antenna boost the signal of a tablet/carputer GPS?

I'm installing an Android tablet as a carputer in my '97 Hunk-o'-Junk Crapwagon, and saw a reddit post detailing a carputer install where OP linked his Jaguar's antenna to a USB GPS adapter. OP also ...
2
votes
2answers
58 views

OBD port power source [closed]

I've read on forums that OBD port can provide max 5A current at 12V. What is the source of the power? Is it coming from battery directly or is it regulated power supply from somewhere else, maybe ECU? ...
1
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1answer
39 views

Turn on 12v car amplifier with ATX POWER_GOOD?

Does anyone know how to turn on a 12v subwoofer amplifier, using the ATX power supply control wire for POWER_GOOD? I am using an Azza model PSAZ-1000A14S, 1000 watt, single 12v rail, computer power ...
1
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1answer
57 views

Practical differences between putting circuit complexity on the ground side vs the hot side

I'm wiring some computer fans behind the fridge in my camper-van to help increase ventilation. As part of this circuit, I have a temperature controlling microcontroller plus relay and a series of SPDT ...
39
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6answers
6k views

Why are there so many relays used in a car, instead of transistors?

Recently I did some work on my car electric circuits. I see many relays are used in car circuits. These relays are used for simple switching, and I wonder why these circuits are based on relays and ...
0
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1answer
69 views

Measuring vehicle's forward and lateral acceleration using a smartphone

I want to measure the acceleration (forward and lateral separately) using an android smartphone device in order to be able to analyse the driving behavior. My approach would be as follows: 1. ...
1
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1answer
86 views

How to reliably sample a sensor during the rotation of a wheel in a car?

I would like to sample the acceleration of the wheel axis (vertically and left-right) N times per rotation (for example once per spoke, but not necessarily). The data would be processed with Arduino. ...
0
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0answers
42 views

Floating Ground Adapter for Car audio line level signal?

I have a an Audi that uses the Bose external amplifier. Bose/Audi designed the system to use a single common between the head unit line out and the Bose amplifier line input, so it is four wires (FR+, ...
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2answers
50 views

Test car phone charger amperage [closed]

I have at car usb charger. It has 2 ports and is rated 2.1A when one port is used and 1A when both ports are used. I attached samsung tablet (N8000) witch requires 2A output. So, tablet isn't ...
0
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3answers
144 views

Using Li-Po or LiFePo4 for diy motorcycle battery

Basically just after opinions on using LiPo or LiFePo4 for building a diy motorcycle battery. My current lead acid battery just died and i'm sick of replacing them after 1-2 years. Background info - ...
1
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2answers
89 views

First Time Using Integrated Circuits

I am building a circuit for a custom application. I have an old Toyota truck, and I keep leaving the headlights on, because there is no warning buzzer! I have designed a circuit that takes 3 inputs: *...
1
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1answer
117 views

Battery isolator reminder for classic car [closed]

I would like to add a small buzzer or led light to the dash of my old MGA which activates only when: a) the ignition is off AND b) the battery switch is on. (i.e., I have forgotten to shut off ...
0
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1answer
59 views

Transient Voltage Protection of an automotive circuit

Im an electronics engineer student, and im doing a project where im designing a circuit which will be used in automotive applications. More specific it contains a PIC controller which has 16 digital/...
0
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1answer
35 views

Run CB Radio from AUX power [closed]

Sorry if this isn't the right place for this. I have a Uniden UH015SX (https://www.uniden.com.au/resources_main/pdfs/uh015sx_OM_2yrWarranty-Updated.pdf) which requires 13.8v of DC power, but I'd ...
0
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0answers
41 views

voltage drop when probing a NPN transistor's emitter to collector, collector to emitter for PNP

I have some old 2SD1785 and 2SB1258, NPN and PNP transistors that I pulled off of a car audio amplifier. Using this site, I tested the transistors in question and find that they fail on the test on ...
0
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1answer
51 views

Switching power supplies with a relay, how to account for delay between connections? [duplicate]

this is my first post on this site (but I will have more, have no doubt), so if I have posted in the wrong section or something please forgive me. Anyway, I am currently doing a battery powered pc ...
0
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1answer
54 views

Wiring a car radio with two power sources

This is on a land rover I'm helping sort out for an off-road expedition I'm trying to wire up the radio with two different power sources, but what I've got at the moment is having some undesired ...
1
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1answer
60 views

Audio amplifier car board

I have a old autoradio (cassette and not AUX input ) in my car. But i don't want change because it pretty. I just want to add bluetooth. I leave fm receiver side for the true audio / radio. I want to ...
0
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1answer
59 views

Check my automotive solid-state power switch schematic for mistakes

I've spent a lot of time designing a simple circuit for my car. Here's what it does: it has 2 inputs, and whenever one of them is triggered, the output switch is shorted, connecting power supply to ...
0
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2answers
78 views

Charging a car battery with two chargers simultaneously

My car, which has a 12v silver calcium battery, is flat and I would like to get on the road as soon as possible. I got two car battery chargers that are not identical, but both can operate at 6 an 12 ...
0
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1answer
77 views

voltage regulation for car computer

I am looking to install a home PC computer for the car. I am concerned about voltage regulation. The car voltage can range from 10 - 14V, so would the standard PC power supply have voltage ...
0
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1answer
67 views

charging and discharging car battery [closed]

Apologies upfront if this is inane... I cannot find a succinct and exact answer to my question though! I have a constant water flow source in my garden - it fluctuates but with a little damming or ...
0
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2answers
174 views

Can I replace FP50N06 with IRFZ44N?

I own a car audio amplifier which uses a DC to DC converter having a MOSFET of the type of FP50N06. However, after prolonged use, the three of the positive rail switching MOSFET cooked and smoked. I ...
0
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3answers
110 views

Digitally Pressing a keyfob button with a microcontroller

For a project I'm working on, I need to press a car keyfob button with a microcontroller. So I soldered two wires to the circuit thing on the keyfob so I can send signals to it. This is what it ...
0
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1answer
37 views

Need component/device to power a light from two seperate inputs

First question here, and don't work on electronics often, so tips are welcome. This might have a very simple solution. I tried to use the schematic editor to the best of my knowledge to recreate an ...
0
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2answers
106 views

Boost +12v from ATX PSU to ~13.5-14.5v [closed]

I understand that what I am doing requires the utmost care and that numerous precautions should be taken in completing a project like this. Out of necessity, I am going to fashion a car battery ...
0
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1answer
83 views

Stabilizing the 12 volts from a car battery

I'd like to put a small gadget that I made into my car and power it from the car battery. The gadget works on 12 volts and the car provides 12 volts also. And the consumption would be somewhere around ...
0
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3answers
103 views

Car battery capacity in colder countries

The capacity of the battery is affected when the temperature drops, particularly Lead-acid batteries. So how in cold countries this situation is solved. In this PDF about automotive batteries at low ...
4
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2answers
228 views

Relay for Intermittent Wiper Function

I want to add an intermittent function to the wipers on my 40-year-old car without any additional switches. The details of the wipers can be found here [http://www.globalsoftware-inc.com/coolerman/...
0
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3answers
74 views

Automotive: how to safely connect the car's power grid to the input of an intelligent switch?

I have an intelligent switch. Let's take this one as an example - it's the one I'm plan on using, unless I find a better one. What I need to do is drive it by the voltage from the car's power grid. ...
0
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2answers
196 views

Bulb replacement in a car 12V 60mA vs 14V 65mA

The climate control in my car needs to have some backing lighting bulbs replaced. Can I use a 14V 65mA bulb instead of the 12V 60mA bulb that is suggested by other people who have replaced these ...
1
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1answer
92 views

Invert ground vs. open “signal” - relay?

first post here. I'm trying to design a circuit to invert a ground/open input signal. I.e., output is grounded when the input is open, and vice versa. I have a feeling this can be accomplished with ...
0
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2answers
90 views

Use of a capacitor to accomodate temporary voltage drop

I recently added a small circuit board to delay my car stereo powering up. The idea was to prevent the stereo coming on in the brief period between turning the key from ACC to START and back again. ...
0
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2answers
66 views

can someone help identify and how to test this component

I'm new to this forum and I am looking to properly identify and how to test this component. It is from a vintage Suntester power timing light Model 45XA, 6-12vDC. If anyone can help in describing ...
0
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2answers
97 views

Why Exactly Car Charger Stop When Car Is Off?

Just out of curiosity, I'm wondering why car chargers can provide no power when the car is off in most cars. Is it because the electrical system that connects to the car chargers is running off the ...
0
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1answer
93 views

Bare bones dual 12V battery isolation circuit?

I'm putting together a bare bones dual battery system for the car so I can run an inverter from the second battery while the car is off. Was thinking I could leave the starter battery as is, connect ...
4
votes
2answers
133 views

Supercapacitor with a rated voltage value greater than 2.7V feasible?

I've been researching into the development of electrical power units for Automotives (motorsports in particular, as I participate in my Uni's Formula Student team) and have started by looking into the ...
1
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0answers
100 views

Flashing of ECUs using UDS

Can someone please tell me if flashing ECUs is a standard procedure? Is it done the same way for all vehicles and for different ECUs? Or do manufacturers have their own methods? What exactly is ...
5
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1answer
121 views

In Field Car Battery testing

I need to determine the "health" of car batteries in the field. My objective is to predict when a car battery is likely to fail from data collected while the vehicle is in use. I am targeting 3 ...
4
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2answers
134 views

How to stop Car Alternator audio noise / buzz?

I connected a Raspberry Pi 2 in the car to add OSMC media player capabilities. However, there seems to be a buzz / hum of background noise in the audio. The noise is correlated to the engine speed so ...
0
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2answers
125 views

How to reverse engineer a motorcycle speedometer? [closed]

I hope this is the correct forum for this type of question. I'm trying to start a project to figure out and create a replacement for my motor cycle speedometer. my goal is to take the current unit, ...
0
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1answer
96 views

12v LED Turn on and Dimming based on either MAP signal, or RPM of Car

I've got a simple 12v Red Led strip installed in my car, and i currently have it hooked upto a relay which turns it on when you unlock it from the key fob (the same as the interior / courtesy lighting)...