The Electronics Engineering Technology program at Lewis-Clark State College is a two-year Associate degree program designed to prepare students for entry-level employment within a wide range of industries.
The INA126 seems to have a cut in requirement before it begins to increase the output signal. Mine reads 0.645V with no weight on the cell. As I slowly add pressure it holds 0.645V until reaching a force threshold and then the voltage slowly climbs as anticipated. I have a different style load cell reader and it does not do this. It will read a force increase as soon as its applied. Why does the instrumentation amplifier have this cut in requirement? Changing out the resistor for a higher gain reduces the cut in, but then the output becomes saturated too soon.
O amigo eu sou um escrito no teu canal e esse projeto de osiloscopio de Leds ficou top Eu já tentei fazer igual mais não consegui você passaria o esquema elétrico desse?
Have you ever seen a video where the refresh rate of a camera matches the spin speed for one blade of a helicopter to move to where the blade in front of it was when spinning (bad explanation) either way it’s sick and refresh rate is an amazing thing to mess with
This student used an INA126 which is a self-contained instrumentation amplifier (laser-trimmed internal resistors!) and lets the user control gain through a single external resistor labeled Rg, in this case Rg = 500 Ohms.
We needed a means of controlling the crane through a glass window pane, and this was the method we chose. Other methods would have required the use of some hand-held device such as a remote-control unit or magnet, and the purpose of this was for random visitors to be able to control the crane from the hallway outside our classroom.
@@lcstate_eet7381 Oh that's pretty cool. Magnetic or capacitive touch would probably be overkill for this yeah, so LDR might be the cheapest approach for this. What if you add a small white LED facing the LDR above it, so that it gets kind of constant light till blocked with finger, that might improve things I think
Indeed, the simplest way would have been to sequence the columns of LEDs digitally using a decoder or shift register. However, the main LED board was designed to use analog driving signals in order to mimic the operation of a legacy CRT display. That way we can do things like Lissajous figures driven by two analog AC signals.
@@lcstate_eet7381 I still hold to my statement that your sweep generation could have been done far more simply. One 8-pin IC, two resistors (one being a potentiometer), one fixed capacitor and one switchable array of capacitors for various sweep frequencies. OK, probably a small series of trimpots to accurize / calibrate it. Maybe throw in a CMOS opamp buffer if it acts like it needs one. All analog, as they should be. Nothing digital (digital doesn't belong in an oscilloscope and nearly never even belongs in a multimeter). B&K Precision did that in a commercial oscilloscope, and it worked remarkably well. I had one for a long, long time.
@@timhofstetter5654 Agreed! There are definitely simpler ways to generate an analog sweep signal, and your proposal works fairly well. A student in a previous course tried something similar using the sawtooth waveform from an astable 555 timer circuit as the sweep and found that the non-linear ramp profile created a noticeable "compression" of the waveform toward the right-hand side of the display. Regulating charging current through the 555's capacitor fixed that problem and gave a nice, linear ramp. One detail I didn't mention for this project is that it was done in a course focused on microcontroller applications, so it's more or less a gratuitous use of a microcontroller to generate a linear ramp analog waveform using an R-2R ladder network.
That would be W. Forrest Mims to you. 8) Why did you use discrete LEDs instead of integrated LED arrays? Just so your array would fill the real estate you laid out for your drivers to make your board tidy? It could have been about 40% of this surface area. BTW... an ever-so-simple 555 timer can be used for the horizontal sweep. The charge on its timing capacitor is easily linear enough for a purpose like this, and you have all sorts of control over its sweep frequency, especially if you use a CMOS version of the timer.
The lack of a standardized LED array was one reason for using individual LEDs. The main board itself is something I call a "half-project" where students assemble the components on the pre-etched PCB and then they add their own vertical and horizontal driving sections. As such, I wanted a "motherboard" design that would not have to be re-done every time my favorite LED array became unavailable. Another reason for individual LEDs is simply to give students LOTS of soldering practice!!
@@lcstate_eet7381 I'll certainly grant the lots of soldering practice! 8) ...and desoldering, when three of the LEDs get installed backwards... 8) That's hair-raising in the middle of an array, where it's so difficult to tell which pin you're heating up. I'd almost be tempted to suggest wire-wrap. Oh, but wait - they could test each row of LEDs as they solder them down, couldn't they? That'd help a lot.
Fantastic video, extremely comprehensive. Lots of videos on the bird meter, but nobody shows the in-depth data on the different slugs, and reading the meters different scales. Thank you for taking the time.
Nice I built a LED oscilloscope based on the lm 3914 from 13 years ago, Back then i use smd led in order to make it it was 20 horizontal × 30 vertical That gave me a 600 dot . with two signal inputs and a trigger circuit. It served me very well with maintenance until I replaced it with an oscilloscope with a tube screen any way thanks for posting
Awesome! Really cool that you're uploading again like the old BTC days. Certainly less viewers than your old well established channel, but just know there's still those of us out there looking forward to these uploads!
I don't give complete instructions for this because it's intended to be a student project where the student must do their own design, construction, and testing of the vertical and horizontal control circuitry. However, the basic LED array and driver circuits are downloadable as a PCB layout file and schematic diagram: PCB layout file (using gEDA's "PCB" circuit board editor software: www.ibiblio.org/kuphaldt/socratic/model/apps/LED_oscope_v2c.pcb Schematic diagram: www.ibiblio.org/kuphaldt/socratic/model/apps/LED_oscope_v2_schematic.pdf
