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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33 views

Does it matter if I shield the antenna wire or the interference source

I have a problem. My car radio is picking up interference when ever I plug a device into the power outlet/ cig lighter. I know that the solution would be to put shielding around the antenna wire, but ...
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0answers
14 views

Does AEC-Q101 Certification mean a part has some ESD protection?

I'm working on picking out some FETs and would like to use some with ESD protection. While picking some parts out on Digikey I keep coming across datasheets that say AEC-Q101 compliant or sometimes ...
0
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0answers
49 views

Is it necessary to have the good car's engine running when jumpstarting [migrated]

When jump-starting a vehicle, one first connects the positive and negative terminals between the two cars: positive to positive and negative (good battery) to a bolt head on the vehicle with the dead ...
2
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0answers
56 views

Android CAN bus connectivity via Bluetooth (or USB) [closed]

I'd like to read sensor data from existing CAN buses using a bluetooth (preferably, though USB would also work) device of some sort. Trouble is, I've never done CAN bus, bluetooth or android ...
8
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3answers
1k views

How do the streetcars in Toronto draw power from the lines?

I've tried googling this but to no avail. I've been trying to figure out how streetcars can draw power from a short circuit. For reference: If I imagine the power lines simplified as a shorted ...
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2answers
50 views

12v capacitor / UPS system [duplicate]

I am looking to make a capacitor/UPS system for a few different electrical components in my car. I want to power the rear view camera, headrest monitors, and possibly the head unit for about 30 ...
1
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1answer
65 views

Detecting vehicle on parking spot

For a project we're working on we need to detect if a car is standing on a parking spot. We're using an ultrasonic sensor for this, SRF05. While using the correct timings we can only sense for about a ...
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0answers
20 views

Troubleshooting my antenna power delay

Awhile ago I build a circuit to fool my power antenna into sensing a constant voltage while I started my car. enter link description here It worked great. So installed a new power antenna and ...
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2answers
54 views

Automotive Logic Signal Switching and ESD/transient susceptibility

Sorry...can't think of a succinct question for the subject line! I am working on a project on my car. The car's existing ECU is connected to a pressure switch, which opens when the A/C refrigerant ...
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1answer
206 views

What do chips like ELM327 and STN1110 do?

What problems are the chips ELM327 and STN1110 solving? If I connect the necessary interface ICs (I mean dumb ICs, like level shifters, inverters, etc., not pre-programmed devices like ELM327) ...
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2answers
124 views

Combine two audio signals

I'm currently building an in-car alert system using a Raspberry Pi. My car has an AUX port (3.5mm jack) which I currently use with my phone - to play music. I wish to be able to play music, and play ...
0
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1answer
79 views

What are the components used for the iPhone-sized car hack? [closed]

Recently two security researchers hacked a car with iPhone-sized gadget according to this link. They didn't release any technical details, but I think we can guess from the picture of the gadget: ...
2
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1answer
66 views

How Do Vehicle Backup Sensors Work?

How do the backup sensors on vehicles work? There are 4 round sensors in the rear bumper of many vehicles to provide a backup alarm. Are they optical or ultrasonic? And what measurement principles ...
3
votes
2answers
141 views

12V Battery Backup Supply for GPRS Tracker

I have little knowledge on electronics apart from following a few guides. I have made a few 7 segment displays, nothing complicated. Recently my girlfriends car was stolen and she has an insurance ...
0
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3answers
280 views

How the Current Flows in a Car?

My BIG question is : why does positive battery cable in a car is directly connected to the starter to crank the engine and does that mean the current actually flows from positive battery post to ...
2
votes
2answers
108 views

How to select a power transistor to protect old school automotive ignition and headlamp switches

WAY back in my past I did some serious EE work, but not having used it for nearly 40 years, I'm a little lost on how I do this... I have some 6 and 12 v cars I'm trying to restore and was lucky ...
0
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1answer
79 views

Electric car control

I have a school project where I have to control the brake and accelerator of a electric car. These two are controlled by a signal and a potentiometer to vary the voltage. The problem I have is that I ...
6
votes
1answer
268 views

Automotive circuit works but with lots of heat. Is there a better way?

The Problem I have a vehicle that is ‘smart’ enough to detect when a trailer is attached. When a trailer is attached it changes ABS and vehicle stability control parameters, turns off the reversing ...
3
votes
2answers
174 views

Low-Side versus High-Side relay driving concepts

What are the pros and cons of Low-Side versus High-Side relay driving concepts in an automotive environment? The questions popped up when I was looking for an 8 channel relay driver IC for a ...
0
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1answer
170 views

IC to interface between digital switches (12V) and microprocessors (3.3V)

I am working on an automotive general purpose ECU where I need to interface 12V digital inputs with a µC (3.3V). The PCB space is limited, so I am searching for a single IC as an interface between ...
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0answers
327 views

How to hook up a Car Stereo for use in Home [closed]

I have a Sony cdx-gt820ip that I would like to hook up in our kitchen. I like the idea of using a car stereo in the kitchen because it has a small footprint and does everything a normal stereo would ...
0
votes
2answers
165 views

best way to detect if vehicle is running

Plan is to place in vehicle Raspberry Pi with camera. And fully automate startup/shutdown of raspberry. So - what is best way to detect that vehicle is running? ...
-9
votes
1answer
84 views

car air compressor power supply unit [closed]

I want to power 12 V 180 W car air compressor from a 220 VAC source, without transformers. I want to power the pump after rectifying the 220V AC. Does that mean the pump will draw 3A or will it draw ...
0
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2answers
98 views

Electric vehicle power component selection help

I need your advice on high power device selection. I'm working with a similar application to this schematic, with the descriptions being in this forum. Without reading through the dozens of pages ...
0
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2answers
119 views

USB car charger with LED

This is related to Is it okay to keep a USB charger plugged into the cigar lighter? - I have a 12v charger that is connected to a phone dock with an integrated micro USB connector. The difference ...
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2answers
114 views

How can I charge secondary car battery? [closed]

I want to install a secondary car battery for a system/project that I am working on. However, somehow I need to be able to charge it while car is running, but not let the car modules use secondary ...
0
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1answer
168 views

Working around voltage drop in a classic BMW

I have an '87 BMW 535is that has had an odd electrical gremlin for years. The previous owner tried gallantly to address as have I. I am not done trying to diagnose and fix the underlying problem, but ...
4
votes
1answer
350 views

Using/Charging a backup battery in a 12VDC circuit

EDIT: I've revised the circuit in response to comments from Andy aka. I have also updated my questions to make it more clear what I am asking. I'm leaving the top paragraphs for completeness' sake. ...
0
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1answer
1k views

hard-wire 4-port usb hub to my car's 12v switched cig outlet

I would like to hard-wire a 4-port usb hub to my cig outlet. I currently have the hub connected to my power inverter and have to flip a switch to turn on the power. My goal is to do a complete ...
1
vote
1answer
105 views

Noise from car amp when grounded to the body [closed]

I am busy installing sound in my car. I have installed an amp and have VCC running to the battery and ground connected to the body of the car. I have noticed that there is noise, seems to be a high ...
3
votes
2answers
265 views

Q: ultrasonic sensors - distance detection

I have a question about ultrasonic sensors. By connecting the car parking sensor to the scope I always get the same wave. But by changing the distance from the sensor, the parking system respond as ...
0
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0answers
83 views

isolate switches in resistor ladder

I am looking to re-purpose some automotive switches in a project. My goal is to extend or relocate the buttons of a garage door opener to my dash board. The buttons on the dash board have 3 ...
0
votes
1answer
122 views

Basic DC Fan Controller

I have been tasked with retrofitting some small fans to an old car, to help move heated air into the footwells. Being a computer-type, I immediately bought some standard computer cooling fans. The ...
5
votes
2answers
237 views

Automotive power filtering, protection - feedback needed

I'm working on GPS tracker for automotive applications. Device should work in 9V-30V supply voltage range. In practice it will be fed from 12V car installation. This enforces the implementation of ...
2
votes
3answers
449 views

Electric car “J1772” charger - “pilot” signal sequencing with passive circuitry

J1772 Some background: Many electric cars are designed to use a "J1772" charging point. The main signal in the J1772 specification is called the pilot. Long story short, the car is expected to ...
2
votes
2answers
345 views

Arduino project, powered by car electric system

I want to assemble an Arduino project that would be powered by car, and also it should be power-independent to some degree. This project will be a simple car alarm system, with gps reciever and will ...
1
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0answers
60 views

What are some good resource for learning how car key and wireless door lock systems work?

I understand that most car keys include a 434MHz transmitter, as well as 125KHz RFID transponder. The 434MHz transmitter is used for operating the door locks, and the 125KHz RFID transponder is the ...
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votes
1answer
93 views

car Battery charger (3.3V)

I have a project in mind, but i'm stuck. I want to power a board (which works on 3.3V, 13/16 mah on reception and 37 mah on emission) with a battery from a car light adapter. It seems that standard ...
0
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0answers
90 views

Condition Car Ignition Signal

Background: I'm working on a project that needs to accurately and quickly measure the rotational speed of the engine in my car. It is a MK3 Ford Focus, and each spark plug has a coil-on-plug that ...
1
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2answers
4k views

Why do we connect a battery to ground when jumping a car?

This may seem like a very simple question, but I've searched all over the place and haven't found an answer. When jumping a car, we connect the + end of the charged battery to the + end of the dead ...
3
votes
2answers
896 views

Detect car +12V using Arduino

I am looking to detect 12+V from a car wire using an Arduino. I have found the following schematic: I know how crazy automotive voltage can get so I just want to make sure the schematic I found ...
0
votes
1answer
170 views

Is there any method to communicate with a car ECU?

I want to build a device with AVR to read the car RPM from its ECU. I don't know how to receive data from ECU at all. The thing is important for me is Reading car RPM. any suggestion? EDIT: The car ...
2
votes
2answers
189 views

Anti-Crank Power Supply for Car

I have a circuit that draws a maximum on 1 amp @ 11v. Its an ATmega328P running PwM through some Mosefts to run some LED DRLs (Daytime Running Lights). I want to prevent the situation where, during ...
0
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1answer
119 views

What causes the background hissing in car speakers?

My knowledge of electronics is very limited, but I think I should be able to understand the answer to this. In a car, if I turn the volume up as high as it goes with the auxiliary cable plugged in, I ...
4
votes
1answer
236 views

Automotive Voltage Regulation for MCU

To supply 5V to a PIC in a 12-15V automotive environment, I have so far been using variants of 7805s, or the HV varieties of PIC. While they work, obviously they aren't really of sufficient protection ...
5
votes
1answer
289 views

Automotive Relays - What is the actual difference?

Or maybe my question should be 'do I really need one?' I have a circuit where I am driving an SPDT relay with a PIC (and transistor). The relay is switching 12V and ~150 mA (it is switching the ...
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votes
2answers
232 views

Diagnosing and programming car/bike ECUs [closed]

I want to learn how to do this. I am interested in a universal programmer (if that exists). Is there a machine (or laptop program) that I can connect all cars and bikes to, and diagnose problems on ...
2
votes
1answer
162 views

Diode selection for truck wiring light application

I need to know what diode I need for a light set up I am working on. The main current flow through the diode is going to be 9v going to power a 55watt roughly ??? amp bulb. There will be ocassional ...
2
votes
4answers
4k views

I'm trying to use 3v LEDs in a 12V circuit, in my car

I'm trying to make a circuit that will run 1-3 LED in a parallel, powered by a 12V power source. I used a voltage divider calculator and it said to use a 100ohm and 33ohm resistor. when I wire them in ...
0
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1answer
440 views

What is this connector called? (automotive blu-ray unit)

I have an automotive grade blu-ray unit and I'm missing a cable to connecti it to a second screen. The cable is the blue one I'm showing in the pictures (LVDS) and it is a universal FAKRA type, ...