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  1. pgib8

    Soft power on circuit

    Yeah, I guess I would just use one mosfet, with extra capacitance at the gate and a resistor to limit the charging speed of the gate. it was just a thought, maybe i'm wrong
  2. pgib8

    another bad circuit

    Hi. I came across another bad circuit at my work. It's producing a ridiculous amount of noise and actually failed conducted and/or radiated emissions during UL certification. This project is not under my responsibility and I'm sharing it because I would like to hear your opinion, to provide you...
  3. pgib8

    Soft power on circuit

    I would let the gate be charged from VIN but add extra capacitance and a resistor. Once power is applied, the gate will charge slowly.
  4. pgib8

    Will it effect laptop's battery if I use charger connected when fully charged?

    I keep mine plugged in almost always. Everything is taken care of automatically. In a couple of years when the battery may actually degrade too much, I'll just buy a new one, provided the laptop still works. Also there are settings. For example you can tell it not to even charge the battery...
  5. pgib8

    LCD is Dim

    Check the voltage on VO as you turn the pot. It should be adjustable just about from Vdd to Vee. Make sure Vee is in fact a negative voltage compared to GND/Vss. Take out the pot. and connect VO directly to Vdd, then disconnect from Vdd and connect to Vee, and see how that interacts. The LEDs...
  6. pgib8

    newbie trying to make a basic monitoring circuit

    You said you want to keep it simple so with that in mind here is what I would do... Use two resistors in series, one is in a safe place (call it R1), the other is where one may tamper with it (call it R2). If R2 is bridged, R1 will still limit the current so things hopefully don't catch on fire...
  7. pgib8

    Why don't I get a Sine wave?

    Quite easy, all you need is a good teacher ;) Declaring a simple array with 10 elements (each element is one byte): unsigned char MyArray[10]; Assign a number to the first element: MyArray[0] = 55; ..... MyArray[7] = 20; .... And the last element: MyArray[9] = 222; There you go, pretty easy...
  8. pgib8

    Why don't I get a Sine wave?

    Regardless of what the OP wants to do, if the task was to generate a sine wave I would totally go with a microcontroller setup. The code can be very simple, 100 lines of code is a walk in the park. The lookup table and timing can all be calculated dynamically at startup. A little bit of...
  9. pgib8

    Why don't I get a Sine wave?

    I've created very pretty sine waves with microcontroller/DAC output (filtering also required)
  10. pgib8

    Looking to get into Atmel programming, few questions...

    well if you're considering other chip manufacturers also have a look at the TI launchpad with the many boosterpacks.
  11. pgib8

    Looking to get into Atmel programming, few questions...

    Getting a board that has a programmer built-in and that does also provide an integrated USB-to-serial interface for debugging is a very good choice, like the middle link. On this board you have nearly no peripherals, probably one or two LEDs and maybe a button. This will be good to learn some...
  12. pgib8

    how to make a non linear load setup for ups testing

    For the inductive load, I'd go with a vacuum cleaner or if that's too much, maybe a blender, or if that's too much some kind of fan. Finding a capacitive load in the household sounds a bit more tricky but buying one or more properly rated capacitors should do the trick. To add some real...
  13. pgib8

    Why don't I get a Sine wave?

    Yeah, maybe use multiple filters in a row, I think they call it a filter with multiple poles, possibly also use active filters and it should give a pretty good cut-off. Possibly combine different types of filters so that the end result is such that the wanted fundamental is still a good signal...
  14. pgib8

    Why don't I get a Sine wave?

    I'm not sure if the following will be in anyway helpful and I'm not sure if it is correct (disclaimer): The square wave already contains the sine wave that you are looking for, along with a ton of odd harmonics. I think you can feed the square wave through a low pass filter that blocks all the...
  15. pgib8

    electromagnetism

    You mean like with a syringe? You know what I really enjoy are opportunities to teach interested people about a complicated subject and see them actually understand it and take enjoyment from learning something new. When you teach someone, 20% of effort can cover 80% understanding, while it...
  16. pgib8

    electromagnetism

    Maybe I got my wires crossed but here are some things I remember (and get ready to scroll buddy). One of my jobs I was doing firmware work for a synchronous switching device for high voltage breakers. The device’s purpose was to try to time the opening or closing of the contacts relative to...
  17. pgib8

    electromagnetism

    Hey AnalogKid, I was just testing you, looks like you passed although you didn't get the A but close anyways. Often times I don't know what I'm talking about, so I just throw stuff out there :-P
  18. pgib8

    electromagnetism

    The most significant difference is this: An electromagnet, you keep pumping current through it, in the same direction, doesn't have to be a lot necessarily but its DC and you use like an iron core. This means more an more of the magnetic domains within the iron start lining up until the core is...
  19. pgib8

    What is the best Program to Design PCB

    I used Altium in the past and yes PCB software is complicated but I thought that Altium was too difficult to learn. I have used gEDA PCB which is free. It's a total pain in the butt, I have to edit some files manually to get things done but it does work and it is free. Now for my all-time...
  20. pgib8

    Mind-boggling schematic of power supply.

    That's what I said, what about them? I think the 12V changes a little (I have to find out) but it definitely stays plenty above the minimum input voltage of regulator. Regulator will dip even when little or no current is drawn. If anything the the problem exists slightly less when more current...
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