Questions tagged [automotive]
Questions about the design of electronics for use in an automotive environment. (Questions about the installation and use of automotive electronics are unlikely to be appropriate for this site.)
947
questions
0
votes
2
answers
37
views
PWM Driver for PIC12F1572
I have rear lights for car (VW Passat) controlled by default with PWM. I want to create another circuit who do like follow:
When I press brake, car send PWM into LEDs and turn it ON. I want to use ...
- 67
1
vote
1
answer
76
views
How can a CAN transceiver that doesn't support sleep mode emulate a logical sleep state?
Here it is mentioned that the controller will be in a logical sleep state?
If the hardware doesn't support this sleep mode, then how will this logical sleep state be achieved? What is meant by logical ...
- 19
1
vote
0
answers
25
views
How to create a load dump test setup using two power supplies?
I have a Keysight N5771A which goes up to 300V but the response time is not fast enough to be used for the load dump test. So I use it to supply the 202V and another power supply to supply the 24V. ...
- 11
0
votes
1
answer
45
views
Measuring voltage on an edison outlet in a hybrid vehicle
Forgive me for what may be a fairly basic question, but I'm a student and I just happened to run into this while doing a recent project.
I own a hybrid car, and in the cab is a 400w inverter with a ...
2
votes
4
answers
2k
views
Help finding a circuit for discharging a high voltage capacitor
I am on a college project where we make F1 style cars for competitions. Ours is an electric car using a 588 V(maximum) battery to drive the motor.
The inverter has a capacitance that, by the ...
0
votes
1
answer
29
views
Why does loading a circuit cause voltage drop in DVOM?
So this question relates to cars but applies to all electronic circuits really.
I was watching a car diagnostic video on youtube and in the video he demonstrates the difference between doing voltage ...
- 27
-1
votes
4
answers
167
views
What is wrong with this circuit?
This is a circuit of a vehicle ECU. It should turn on the ECU but there are some mistakes and the ECU won't turn on but I can't figure it out:
- 25
3
votes
3
answers
69
views
Bypassing battery to power car while camping [closed]
I'm considering going camping but I only have a car, not an RV. The campground has a 50 amp socket for RVs.
In order to have power insider the car for air conditioning, charging phones and laptops, I ...
- 133
0
votes
0
answers
14
views
Simulink question about a electrotechnical system (simple autonomous vehicle)
I am rather new to all the simulation work and its complex applications. I have been tasked to work on a rather complex project that is creating autonomous vehicle digital twin and then anayaize how ...
- 1
4
votes
2
answers
584
views
Will a buck converter clean the power output from an automotive?
I want to permanently attach an ESP32 module and an LTE modem/hotspot to my car. I want to power these two devices using the car's cigarette lighter socket. The socket gives 12 VDC so I will be using ...
- 41
0
votes
0
answers
34
views
Lithium battery pack in series or parallel
The goal is to build a 200V Lithium battery pack using 21700 cells.
I am trying to make a design decision on lithium battery pack architecture for an electric vehicle and it boiled down to below two ...
- 1
3
votes
1
answer
93
views
Charging car battery with another car - circuit schematic
I came across an example in a textbook that talked about charging a dead car battery with another car battery. They provided this picture of how to connect the two batteries: -
Source: Engineering ...
- 3,656
4
votes
3
answers
521
views
Choosing a relay - what are these extra components for?
I'm working on a project for my vehicle which will involve a few relays controlled by toggle switches.
I'm searching online for relays that fit the parameters I know I'm looking for (voltage, current ...
- 155
1
vote
1
answer
44
views
51 V clamp on load dump; will this IC survive?
This is about the Texas Instruments TPS2HB50-Q1 40-V, 50-mΩ Dual-Channel Smart High-Side Switch.
Vbb is the battery (suppy) voltage
Page 7 gives a VbbCLAMP > 58V
...
- 1,050
1
vote
1
answer
38
views
Reading a resistance to earth sensor with a microcontroller
What are the options for reading a resistance to earth sensor from a microcontroller?
Scenario: I'm building a digital dash for a vintage car, using a Teensy 4 as the microcontroller. The car is a ...
- 1,185
-1
votes
1
answer
44
views
Confusing terminology? [closed]
I posted this question at motor vehicle stack exchange but I believe it's more suited for this.
I've noticed that many computer errors (diagnostic trouble codes PXXXX) in cars use confusing ...
- 27
1
vote
1
answer
42
views
Will this circuit work for wiring a 3.8v screen into my car's power? [closed]
I'm trying to wire a 3.8V screen, 3.8V battery, and my car's 5V power source together and ensure that the device will be powered by the 5V power source when it's available and that the battery is ...
- 11
0
votes
0
answers
55
views
Should the DC-DC and solar charging go through the main fuse or dedicated fuse?
I am planning a 12V dual battery setup to be used in a car. The aux battery is a LiFePo4 battery and it will be charged via a combined DC-DC and solar charger (50A, fuse 65A).
I want to add a fuse and ...
- 1
2
votes
1
answer
78
views
Purpose of an inductor in an automotive brake light switch
I recently opened a brake light switch I replaced in my car. Here is a quick schematic I drew up of the switch design and the way it's wired:
V is the switched 12V supply feed. SW1 is normally open, ...
- 21
2
votes
4
answers
266
views
How to use a capacitor to maintain power when switching between car batteries
I've added a 'House Battery' to my vehicle, which I keep charged by various means, including solar panels. When the vehicle isn't running, I can switch various accessories from the Car Battery to the ...
- 137
1
vote
0
answers
69
views
How do I combine positive and negative pulses into one single signal?
EDIT: I kinda solved the problem. I swapped both diodes polarity and then added an op-amp to amplify the resultant signal.
I'm trying to emulate a motorcycle crank pickup signal as shown by CH2 below (...
- 31
3
votes
4
answers
110
views
What is the optimal method for interfacing a 12VDC or 24VDC relay using a 48VDC supply in an automotive application?
I need to interface a 12VDC or 24VDC relay into a 48VDC (nominal voltage) battery pack for switching applications in my automotive design.
Directly driving the relay coil with the 48VDC battery pack ...
- 31
2
votes
1
answer
43
views
How to test or substitute a frame ground point in a modern, small-motor vehicle? [closed]
I have a ATV that I am trying to install a horn and light set it. Lights worked out fine but the horn worked for a bit then stopped, and now a replacement horn keeps blowing fuses. I checked and the ...
- 139
0
votes
2
answers
86
views
Fog lights on motorcycle with 2 power sources
I am trying to add fog lights to my 2023 fltrx. I am having trouble figuring out the wiring and praying someone here can help. I would like a setup where:
I turn on the high beams and the fog lights ...
1
vote
2
answers
106
views
Ways to ground electronics in a car
I'm trying to set up an electronic device to operate inside a vehicle. Power should be 12v 1 amp fuse. I was going to use a cigarette lighter for power, but the instructions say to ground one of the ...
- 11
0
votes
1
answer
77
views
What is the point of triple JCASE automotive fuses?
Some JCASE automotive fuses come three in one enclosure. What problem do they solve? What do they do that three individual fuses couldn't do?
{My pictures}
The BUSSMANN MPF spec sheet (PDF) says;
&...
- 17.6k
3
votes
2
answers
155
views
Identification of a 12 V Quick-connect disconnect
I am looking for help in identifying a specific type of Quick-connect disconnect:
It's used in the context of 12 V vehicle or boating electronics (think 12 V "cigarette lighter" outlets, ...
- 133
0
votes
1
answer
58
views
Missing a part from a plug for a DC car charger, don't know where to find it
I am in a predicament, I need to replace the part highlighted in blue but don't know what it's called or where to get it. The black nut holds everything inside, and it came loose so everything fell ...
0
votes
1
answer
58
views
I need a datasheet for an IC of 8 Pin 3*3*0.9 dimension with Top marking 20042Q Q2KK46 2N1B
I need datasheet for this 8 Pin IC with top marking 20042Q Q2KK46 2N1B and its Dimension is 3*3*0.9. This IC is used in automotive vehicle Power Conversion Module.
- 85
0
votes
2
answers
89
views
CAN protocol for communication between EV and Charging equipment
I am trying to understand (and hopefully build) DC fast chargers (GB/T) for electric vehicles, specifically the communication between the Electric Vehicle Supply Equipment (EVSE) and the electric ...
- 443
0
votes
1
answer
143
views
Battery Kill/Disconnect Switch on Truck
I have a question with regards to surge and continuous amperage ratings as they apply to battery disconnect switches.
I recently had a battery kill switch installed on my light duty truck as a theft ...
0
votes
3
answers
154
views
Using capacitor bank in parallel with lead acid battery
I saw some DIY projects about boosting car lead acid batteries. A supercapacitor bank is connected in parallel with a lead acid battery to stabilize the supply.
However, in the market, I can only find ...
- 343
-1
votes
1
answer
78
views
I need help identifying what this might be [closed]
This is my DRL module for a 1998 Toyota corolla. Not exactly an easy find to replace. This three pin SMD is on the board. I initially thought it might have been a transistor, but PCB is marked as ZD, ...
0
votes
1
answer
234
views
ESP32 TWAI/CANBus bus errors cause bus off state
I have multiple devices using ESP32-WROOM-32E and TWAI (CAN). There was an issue where they would have bus errors and then fail to recover via twai_initiate_recovery(). I solved the recovery issue by ...
- 23
0
votes
0
answers
59
views
Calculate car battery charge time given constant voltage
I just bought this 55 Ah AGM car battery https://www.costco.ca/energizer-35-agm-battery.product.100408225.html it is currently at 11.9 V. My car idles at approximately 13.6 V. How can I approximate ...
- 313
10
votes
8
answers
6k
views
Why don't we use the 7805 for car phone chargers?
What are the disadvantages of using a 7805 (with a heat sink) to use in a car USB phone charger?
Another option: It gives a 1 A current, so could I maybe wire two of those and give a 2 A output?
In ...
- 287
0
votes
0
answers
43
views
How to safely use a USB bus powered device in a car
I want to use a USB bus powered USB 2.0 audio interface in my car for DSP.
Specifically a MOTU Microbook II https://motu.com/products/motuaudio/microbook_old
My car doesn't have a USB port near the ...
0
votes
0
answers
61
views
Protecting a Schottky diode against negative spikes greater than its specified V_rrm
It appears this can be made to work, but I am not sure how. Related:
Protection against transient voltage spikes regarding ISO7637-1/2: TVS diode with Schottky diode suitable?
or a 40V schottky plus ...
- 1,050
1
vote
1
answer
133
views
Does car alternator speed increase during load dump?
I am trying to understand the mechanism of voltage surges during load dump in automobiles.
As per this article -
The load-dump event has two components. First is the pulse amplitude (VP), which ...
- 2,621
0
votes
1
answer
75
views
What does this coil do in car door handle
This door handle is from a Range Rover L405. I tried searching car manufacturer's documentation and car door handle tear downs, but I cannot find what this coil is doing in the the door handle.
This ...
- 107
1
vote
3
answers
121
views
Electric fan motor acting as generator
I wired electric 12V DC fans to my vehicle. Fans are relay controlled by the negative. Relays are controlled by a thermal switch. Fans, fans relay control and ignition are all fed through the same ...
1
vote
1
answer
54
views
Hacking an RC car controller using an Arduino to electronically control an RC car from computer [closed]
I want to control an RC car from my computer so I can link my RC car with my racing wheel and pedals. To do this I was planning on modifying a dumbo X6 controller and connect an Arduino to it by ...
- 11
3
votes
2
answers
114
views
Using a PCIe 6/8-pin connector on a modular PSU to power on a car head unit temporarily
I would like to temporarily wire up a standard 650W ATX to power on a car head unit to check if it is working for about 30 mins. Based the pinout below, do I hook up pins 1 and 4 (or 1 and 5) only?
- 31
1
vote
0
answers
64
views
Relay to switch between 2 circuits
I am a novice with regard to electrical circuitry, and am in search of a potential solution for something that spans across the automotive/electrical engineering universe. I am working on an engine ...
- 11
0
votes
0
answers
69
views
How to use a CAN BUS USB Connector
I have one of those "cheap" ODB2 CAN bus cables to access the CAN bus of my car with a software. I would now like to log the CAN bus. I would like to develop my own software for this. ...
- 65
0
votes
1
answer
55
views
Automotive transients: which rail goes how?
Presumably it would depend on each transient
http://www.sft-lab.com.cn/uploads/ISO_16750-2-2010.pdf
http://sft-lab.com/uploads/ISO7637-2-2011.pdf
Or is there a more general rule - i.e. when a -100V ...
- 1,050
0
votes
1
answer
79
views
Electrical tachometer
Could anyone explain to me how electrical tachometers work? I know how mechanical ones do, with cable and drag cup. But i can't find any info or illustration what components drive the electrical ...
- 183
0
votes
2
answers
180
views
Fuse tap direction. Please help me understand which way is correct
I have a car fuse tap and was wondering if it is directional and why?
Please help me understand from bottom 2 variations which direction should I install it and why.
Thank you!
Fuse Tap:
- 103
4
votes
3
answers
323
views
Are ATmega48/168/328 suitable for automotive applications?
I'm trying to figure out if it's ok to use ATmega48 in a homemade project involving some safety-related aspects with moving vehicles. (the project will be a control board for excavator joysticks)
...
- 886
3
votes
2
answers
133
views
What happens when you pull too much power from the DC-DC converter of an electric car? [closed]
Electric cars use a DC-DC converter to charge the 12 V service battery and power the various 12 V devices from the ~400 V traction battery.
What happen if you pull too much amps from it? Does it break ...
- 131