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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25 views

Electrical issue in vehicle - horn and 12 volt (fuel gauge) [on hold]

Here is what I have been dealing with. Posted over on my vehicle specific board, but no one seems to have any idea. Instead of reposting everything hashed over there, I will post the original question ...
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1answer
52 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
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2answers
40 views

OBD port power source [on hold]

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 ...
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0answers
444 views

Which 18-pin automotive connector is this? [migrated]

What type of automotive connector is on the images below? The last image (from device docs) says "pa66-gf35" which leads me to this Tyco Electronics connector catalogue where this "housing material" ...
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0answers
4 views

Create Car Battery Load from Smaller Batteries [migrated]

I want to determine if it is possible to chain together smaller household batteries to produce the equivalent output of a 12V car battery (temporarily). There is a practical reason for this bizarre ...
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1answer
33 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 ...
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1answer
49 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 ...
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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 ...
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1answer
54 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. ...
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1answer
82 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. ...
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0answers
34 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
44 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 ...
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3answers
105 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 - ...
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2answers
87 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: ...
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1answer
115 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 ...
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1answer
51 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 ...
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1answer
33 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 ...
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0answers
38 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 ...
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1answer
50 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 ...
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1answer
48 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
53 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 ...
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1answer
57 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 ...
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2answers
73 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 ...
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1answer
71 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 ...
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1answer
60 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 ...
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2answers
129 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 ...
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3answers
96 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 ...
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1answer
36 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 ...
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2answers
90 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 ...
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1answer
81 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 ...
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3answers
100 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
202 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 ...
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3answers
67 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. ...
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2answers
161 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
85 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 ...
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2answers
85 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. ...
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2answers
65 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 ...
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2answers
92 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 ...
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1answer
83 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
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2answers
130 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 ...
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0answers
82 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
votes
1answer
119 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
122 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
122 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
79 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 ...
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1answer
95 views

Actuating a horn

I recently tried to sound a horn (the type normally used in cars) using a 12V battery. The problem is that that, if I directly connect the horn's terminals to the battery, it works perfectly fine. But ...
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1answer
61 views

Designing amplified speaker for legacy car navigation system

We have a 2003 Honda Odyssey with built-in nav and stereo. The two were integrated -- the nav audio went through the stereo, there was also a mute signal to signal the stereo to play the nav audio on ...
0
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1answer
90 views

12V active-low on/off switch

I have a microcontroller that I want to install in my car. One wire coming from the car supplies +12V from the battery independent of whether the car is on or off. This works fine to power the ...
2
votes
1answer
76 views

220µF 35V capacitor replacement

I'm using this circuit to run a small device within my car (12V): Now I need to consider the height of the PCB and C1 is currently 10mm height. Is there a way to replace this component either with ...
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1answer
28 views

~12VDC+ Automatic Dimmer Switches

Most automotive vehicles typically have their interior lights fade out 30 seconds or so after the doors are closed. The way I understand it, closing the door will usually depress a momentary on/off ...