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  1. Braeden Hamson

    Very high current power supply

    I am in the process of building a ~300A power supply with the intention of testing fuses at 300-70A over the course of 0.01 seconds to 60 seconds. So far I have an appropriate heatsink, 1 AWG conductors, and 300A capable contactor. I'm confident that all of my supporting elements are capable of...
  2. Braeden Hamson

    Recommendations for a battery and dc dc converter powered system

    I'm part of a student EV racing team. In my EV I have a regular 12V battery and a 300V - 12V dc dc converter. When the vehicle is first powered on, the 12V battery powers the systems long enough for the 300V supply to take over. In the past I've connected the output of the dc dc converter to...
  3. Braeden Hamson

    Building a supply to regulate between 400A-100A

    I've got a bit of a bear of a problem to tackle. I need to determine the rating of in house fuses for my student racing team. This is an overcurrent protection fuse for a 21700 cell. The issue is that a the 21700 we're using can handle 45A and not really mind. This means the fuse for overcurrent...
  4. Braeden Hamson

    Audio Source Switching

    Hello, I've been having a pretty persistent problem switching between two audio sources, one is a generic bluetooth radio from amazon, the other is an Adafruit Soundboard FX https://www.adafruit.com/product/2220 I'm using a Maxim Integrated source selector chip...
  5. Braeden Hamson

    Op amp comparator troubles

    Above is my circuit it used the LM2903 op amp https://www.mouser.com/datasheet/2/389/cd00000534-1795799.pdf One half of the chip is grounded and not used. The other is functioning as a comparator. The circuit should function as a brake light switch. Such that when the BSE_IN voltage is...
  6. Braeden Hamson

    Sensing 0-10 RPM of a shaft continuously

    I feel like I'm really over thinking this. I want to measure the speed of a shaft at low RPMS down to zero to detect when it first turns. I think a hall effect sensor system is a good candidate. If I mount the magnets on the shaft I will be able to detect a change in voltage indicating the shaft...
  7. Braeden Hamson

    Why do relays struggle to switch high voltage low current loads?

    I'm reading through this datasheet: https://www.mouser.com/datasheet/2/307/en-g7l_x-1061788.pdf On page 5 it talks about microloads: These Power Relays are suitable for switching and breaking high-capacity DC. At high-voltage and low-current, breaking characteristics may become unstable. For...
  8. Braeden Hamson

    Audio noise problem.

    So I'm effectively building my own bluetooth speaker. I have an RN52 bluetooth module mounted to a PCB I made. https://www.microchip.com/wwwproducts/en/RN52 I then output the audio from the bluetooth module to an audio amp...
  9. Braeden Hamson

    Best course of action for high current DC supply

    Hi, I'm on an FSAE team that's making an electric car. We're making a battery pack out of discrete 18650 cells. In the pack every cell must have a fuse between it and its bus bar. So we have to size the fuse and, rate it for the appropriate current. Somewhere from 300A-200A at ~1V. I need to...
  10. Braeden Hamson

    Advice on setting up realistic documentation standards for a student club

    I'm part of a FSAE team at my university and I'm looking to make function just like an engineering firm would. (Tips on that unrelated to my question are appreciated too) Since we're going to begin designing soon I'd like to set up a documentation format that is similar to that found in the...
  11. Braeden Hamson

    Changing a positive and negative audio signal to positive only

    Hey guys long time no post, I've got a standard audio signal out if a computer which has a positive and negative portion. I'd like to shift the whole signal up so it's only positive. I've seen this done with a voltage divider where the signal is connected to the node of R2 that isn't connected...
  12. Braeden Hamson

    Sonicator

    Braeden Hamson submitted a new Project Log: Sonicator Read more about this project log here...
  13. Braeden Hamson

    Varying the output frequency of an ultrasonic driver board

    Hey guys, So I've got an ultrasonic system with a driver board and transducer. I would like to be able to vary the output frequency, as I've developed a horn that resonates at 26 kHz and not the 28 kHz the board outputs. The circuit looks something like this...
  14. Braeden Hamson

    Power calculations aren't this easy are they?

    So uhh, I realized today that some of my basics are shaky. Lets say you have a device that consumes 10W of power, and it runs for 5 hours. Did it consume 50 watts? What if it ran for 5 seconds? Now lets say you have a resistor that is 1000 Ω, running at 10 V. P = V^2/R so 10V^2/1000Ω = 1 W. If...
  15. Braeden Hamson

    What is this piece in a cell phone camera?

    Hey guys, I pulled apart a cell phone camera and found what looks like a filter but as far as I can tell doesn't act like one. But hey I can only see in visible light. This sat right above the sensor. [mod edited to correct images]
  16. Braeden Hamson

    Is anyone an expert in wafer fabrication?

    I don't need an "expert" per say, I'm simply looking for someone knowledgeable in wafer manufacturing to answer a question. I'm writing a paper on how the electronics industry has impacted the Chinese economy, specifically the middle class. In my research I've found that Chinese manufacturers...
  17. Braeden Hamson

    I think I can log in by pressing "Forgot password"

    Its very strange I've kind of forgotten my pass word. Yet as soon as I press forgot password, boom. I'm logged in.
  18. Braeden Hamson

    What should I do with unused outputs?

    First off, damn this new website looks nice! I really feel like I should know this answer but just to be safe. I'm going to use a 74HC163 without any other counters. http://www.ti.com/lit/ds/symlink/sn74hc163.pdf ←Datasheet Therefore I don't need the "carry out" pin. I know that you should...
  19. Braeden Hamson

    A couple of questions on accelerometer specs

    So I've joined my schools Formula SAE racing team. Pretty neat. They've stuck me on the task of building an impact data logger for their car's impact attenuator. The impact should not exceed 18G max. Taking into account the length of what is in essence a crumple zone, I've calculated the main...
  20. Braeden Hamson

    What's up with my ground plane?

    So here's my first board design: https://jlcpcb.com/quote/gerberview/aa2ca0f4-898b-44e2-bb7c-5b7aad202830_2_53_1_0_0.html If you look in the upper right corner, the ground plane is striated. Then if you look towards the center that ground plane is solid. I have no clue what is going on. I'm...
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