New answers tagged automotive
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You should see the "beat frequency" between the two flasher rates. I suspect modern cars, especially from the same maker, might have rates that are almost exactly the same (crystal controlled).
The rate is apparently specified in (paid standard) SAE J590 (60 - 120 flashes per minute, with 90 being the ideal).
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Figure 1. Beating of two frequencies. (Illustration by Transistor.)
Any two systems operating at differing frequencies will "beat" at the difference between the two frequencies. So if one turn signal / indicator / blinker is running at 60 flashes per minute and another at 62 then they will come into phase twice per minute.
Links:
Beat (acoustics).
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It's not you, it is a real thing.
While there probably is a specified frequency range for turn signals, there is no one standard frequency. In most cars today the freq is determined by one of the many microprocessors running the vehicle.
Back when the flasher was an electro-mechanical device that used a bi-metallic strip that bent when heated by the current ...
1
The camera and radar are ASIL-B level devices. In a Level 2 ADAS, if they fail, they fail passively such that the driver is warned to take over.
Being ECU inputs (and not logic 1/0 type) detecting stuck-at for radar and camera on the ECU interface side doesn’t make sense. Loss of signal is enough.
Do these sensors need internal diags to detect stuck-at? I ...
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In a vehicle you really have no choice - ground IS the chassis. You can get your 0V from the battery or the chassis - they’re tied together with heavy wires.
I’d suggest you have a look at the wiring diagram of a late model vehicle to get an idea of how the manufacturers resolve your issue. The average vehicle has a number of electronic control units ...
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Should I use an LED or look for some other light source? (I am reading the old posts related to LED on and off latency).
I've built strobe lights for a 20 kHz camera system. For simplicity I used an array of 1W Cree white LEDs, a 12 V power supply, a resistor, a power FET for switching, and some optics to focus as tightly as I could. With this setup I ...
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Almost certainly your problem is that you are attempting to use white LEDs. These LEDs use a blue LED and a phosphor which provides the other colors. The phosphor has a fairly fast turn-on time, but has a long persistence time, so latency is not the issue.
Persistence for white LED phosphors is typically in the milliseconds, so your target of 20,000 RPM (333 ...
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The question is not whether you can, it is whether you should, and you should not.
And for a 10A load, a relay that is only rated to switch 3A is not a good idea, because the contacts are not rated for switching 10A. The contacts can heat up more than intended due to the current, so they can degrade faster and might even weld together. Especially when ...
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"My question is this : for 500ms can i use this 5v relay (3A) and if not why ?"
I would advise you to use switches made of semiconductors like MOSFET for switching which are more fast switching components than the magnetic relays. These magnetic relays are not much sensitive and efficient at high switching frequencies. While, on the other hand, ...
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According to the datasheet, there are two series of relays FBR51 and FBR52.
Both are available in 6, 9, 10 and 12 volt versions.
For the FBR51 series, the coils are rated at 0.6 watts
6V^2/60Ω = 0.6W
12V^2/240Ω = 0.6W
For the FBR2 series it's 0.8 watts
6V^2/45Ω = 0.8W
12V^2/180Ω = 0.8W
See page 4 for the voltage and coil resistances.
What happens if you run ...
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Chassis in vehicles is used for the return back to the battery all the time, so you should be OK doing that. You just need make sure you have a good, low resistance, moisture resistant connection where you tie the negative side to chassis.
Also, you need to make sure you properly fuse or otherwise protect the connection from the + side of the battery to the ...
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You definitely need to connect the Dc-Dc converter negative input to the battery negative - whether directly to the battery negative or to vehicle chassis is a matter of convenience.
If you want the DCDC converter output to be isolated from the vehicle electrical system, the negative side of the DC-DC converter output and its loads must not be connected to ...
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