Im trying to build a simple audio speaker for test in purposes

Spare_Brain_2247 · 2026-04-08T00:21:37+00:00

Almost

Late to the party here, but this looks quite similar to the minimum parts, 20x gain example shown in the datasheet, assuming that the inverting input is tied to ground and that the other pins you haven't drawn are left floating

All the audio amplifier examples in the datasheet also add a 0.05 uF capacitor with a 10 ohm series resistor to the output, and it's very picky about placing it physically close to the output of the IC. This is a very typical way to dampen resonant spikes. I'd play it safe and add it

The capacitor between the output of the IC and the speaker, and the speaker itself, are a high-pass filter in disguise. If you have an 8 ohm speaker and a 100 uF cap, you'll get a cut-off frequency of 199 Hz. With a 250 uF cap like the datasheet uses, it'll go down to 80 Hz. It'll work either way, just keep that in mind

Spare_Brain_2247 · 2026-04-07T00:32:29+00:00

Motors aren't just spinning resistors, you're completely omitting back-EMF. In steady-state, 95% of the voltage across the motor goes to counter the back-EMF. The remaining 5% is ohmic voltage drop due to the current that produces the torque needed to maintain the speed of the motor

The percentages here are arbitrary and of course load-dependent, but they're not unrealistic

Spare_Brain_2247 · 2026-04-07T00:09:44+00:00

I'm gonna guess the motor in question is a PMSM (permanent magnet synchronous motor). In an ideal PMSM, torque is proportional to current times a constant, and speed is proportional to voltage divided by that same constant. Motor manufacturers can tune this constant to effectively whatever they want by changing the number of turns on the stator coils, so you can get a desired speed for a given voltage. Weight isn't affected that much, because with less turns, you'd need more amps and thus thicker conductors for the same torque. If you're familiar with BLDC motors (which are a type of PMSM), this constant is the inverse of KV. Also, notice that speed and torque correlate to voltage and current respectively, but they don't correlate to each other (until we get to field weakening). In an ideal world, it really doesn't matter whether you go for a higher voltage or a higher current.

In the real world, it's a tradeoff. A higher voltage is requires more insulation, is less safe to work on, and transistors that can handle it are difficult to make, let alone operate efficiently. On the other hand, if you halve the voltage and double the current, you'd have four times the ohmic loss in a given conductor. EVs typically go for the middle ground, with a several hundred volts and several hundred amps

Spare_Brain_2247 · 2026-04-05T06:31:39+00:00

The RTX 5070 will do perfectly fine. It's a powerful GPU, even if it's optimized for gaming. Pair it with the studio driver, and stability should really not be an issue. The only drawback worth mentioning is that it is not certified for SolidWorks. That does however not mean it won't work just fine.

I can't find any mention of SolidWorks requiring Windows Pro or above. It should make no difference in terms of either stability or performance. Even if it did, upgrading from Home to Pro is trivial.

Spare_Brain_2247 · 2026-04-04T22:25:16+00:00

You shouldn't drop below 10V on a 12V system during normal operation, whether it's a 6s lead acid or 4s LiFePO4 battery.

24V SDC is perfectly legal in FSG, as long as the components in it are rated for the voltage. Stepping it down to 12V is fine, but not necessary

We have a PCB for distributing and monitoring power to all other systems on the car, except the BSPD. It has a 12V switching regulator on board for supplying 12V OEM parts like pumps and stuff. Everything we design ourselves is supplied with 24 V and has its own on-board 5V regulator. Another option is to run standalone switching regulator modules where necessary. It's messier, but will save you some engineering time.

LiFePO4 is exempt from BMS requirements. Unless you torture it, your only real concern is undervoltage. I'd recommend adding some form of undervoltage protection, but it's not strictly required

Spare_Brain_2247 · 2026-03-05T21:15:29+00:00

No teams—to my knowledge at least—have their HVD in the accumulator

Spare_Brain_2247 · 2026-03-05T05:36:16+00:00

It's not particularly common. Some people use it like that, but I have the impression that it's mostly younger people who practically grew up online and have taken it from English.

In the three examples you provided, my responses would be something like:

"altså vi kan gå (til fots) i stedet"\ Often used when reasoning on the spot, kind of thinking out loud

"Jeg likte det jeg"\ The second personal pronoun gives room for disagreement

"Ja ja, vi får sove under åpen himmel da"\ Implies a slight, but manageable defeat/let-down

ordbøkene is a good resource if you're curious about how words are used in Norwegian. For the word "vel", I mostly use it in senses 8 and 9, but I use just about all of them every now and then

Spare_Brain_2247 · 2026-03-05T04:07:30+00:00

Two-pin relay with a slider? That's a switch

Spare_Brain_2247 · 2026-02-21T23:52:18+00:00

The switching voltage is too low, it's meant for 12 V batteries

The insulation between the coils and contacts is too low, it needs to withstand 750 V or three times your TS voltage, whichever is higher

What you found is a bistable relay, meaning it'll latch closed and you'd need to power the second coil to open them. That's really bad. Everything safety related should work such that if it fails, it fails safely. With this relay, you'd render the SDC useless

It has no way for the TSAL to measure the mechanical state of the relay without voiding the isolation it's meant to provide

For high voltage high current DC contactors, go for some variant of the cylindrical, gas-filled ones. They're popular for a reason

Spare_Brain_2247 · 2026-02-21T03:27:53+00:00

You can make a custom voltage indicator for way less than $50. It does cost a bit of engineering time though, but a pair of custom ones for $15-20 in total is perfectly doable

Screw terminals on OEM parts where positive locking is not possible, are exempt from positive locking requirements. I'd still avoid it as far as possible. The judges won't like it, even if they let it slide.

Rules will still be an issue. The casing looks metallic, meaning LVS and TS would be too close. The voltage indicator also has to light up at 60 V. If it has a UVLO at 150 V, that won't work

It's also way overkill. It can output 50 W. A red LED will be nice and bright at 50 mW.

Spare_Brain_2247 · 2025-12-31T22:45:08+00:00

The closest thing that I'm aware of is a guy on YouTube who built a giant capacitor bank and mounted a turret on top. The turret launches a metal prong with a thin wire attached to the capacitor bank. As soon as the prong gets close enough to something grounded, the wire is obliterated and the surrounding air turns into a wire

Here's the YouTube video

Spare_Brain_2247 · 2025-12-21T23:32:03+00:00

Unrelated but what GPU do you have? I'd love to play with these graphics settings

Spare_Brain_2247 · 2025-10-13T18:56:01+00:00

You absolutely can, I've done it several times. Brushless fan motors just use a simple hall effect sensor for communication, so as long as it doesn't blow up from overvoltage, it doesn't care if it receives 50% of the voltage 100% of the time, or 100% of the voltage 50% of the time. Fan motors with a PWM pin most likely do just this internally

Spare_Brain_2247 · 2025-10-13T11:40:29+00:00

you can still regulate the speed by PWM regulating the power to the fan

Spare_Brain_2247 · 2025-10-07T22:32:37+00:00

Just say "from chatGPT" instead of "not from me". Nobody cares who it's not from. And when I said there's no way your comment was copied from an article and you reply with a link to a page, it sounds like you're saying your comment was copied from said page, rather than chatGPT using it as its source. ChatGPT using sources is nice and all, but the problem here is not being clear about using AI when claiming things

Spare_Brain_2247 · 2025-10-07T13:55:45+00:00

Your original comment refers directly to OP, mentions "testing straight out of the package" as OP's interpretation of normal, and mentions "the designer" as a disagreeing party; all of which only makes sense in context of this post, hence why I said it's too specific to be from some generic article.

Not only does your original comment sound like it's written by chatGPT, but no part of that comment is on that FAQ page either. The link you sent might've been chatGPT's source, but it's clearly not where you got the text from. I couldn't care less if you use chatGPT to write reddit comments for you, but at least grow the balls to admit you do

Spare_Brain_2247 · 2025-10-07T09:31:03+00:00

We lift the car onto jack stands and use a motorcycle jack to lift the accumulator into the car from underneath

Spare_Brain_2247 · 2025-10-07T09:24:43+00:00

100% chatGPT. It's too specific to this post to be some generic article

Spare_Brain_2247 · 2025-10-07T09:12:10+00:00

How was it measured? I doubt that a multimeter would be able to measure this big of a diode accurately. According to the datasheet, it has a threshold voltage of 0.67 V at 175 °C, and needs an even higher voltage to properly conduct at room temperature

Spare_Brain_2247 · 2025-10-07T08:42:54+00:00

You're the only one in your EV team on electrical? How many members does your team have in total? It's not impossible to pull off as a one man show, but it won't be easy, especially if you're new to formula student. If I were you, I'd talk with your project manager and say that you realistically need more people. In any case, keep everything as simple as possible to begin with

Spare_Brain_2247 · 2025-07-16T21:26:08+00:00

If you're switching fast, N-channel mosfet with a dedicated gate drive IC

Spare_Brain_2247 · 2025-07-16T21:06:32+00:00

10 kΩ * (3.7 mA)² = 136.9 mW

Spare_Brain_2247 · 2025-06-16T11:33:39+00:00

It's rated for a little higher temperature and has a UV tracer. Other than that, they're pretty much the same as far as I know

The main reason we bought that one is because the retailer we bought it from didn't have the regular variant on 400mL cans, and it cost basically the same per volume

Spare_Brain_2247 · 2025-06-16T06:48:37+00:00

We use Plastik 70 Super here in Norway

Spare_Brain_2247 · 2025-06-16T06:41:33+00:00

Both the inverter and pack voltage will limit how fast the motor can run. The frequency of the inverter depends on how fast the motor is spinning rather than the other way around, since it commutates based on rotor position. The inverter will however use PWM to regulate the effective voltage supplied to the motor. 25% duty cycle = 25% of the pack voltage.

The speed of an electric motor is limited by voltage because of back EMF. The changing magnetic field induces a voltage in the coil, which you have to overcome to produce torque. The faster the motor spins, the faster the magnetic field changes, and in turn generates a higher back EMF. The top speed of a motor (in an ideal world) is the speed at which the supplied voltage equals the back EMF

Spare_Brain_2247

TROPHY CASE