Search results

Search Forums New Posts
  1. J

    PCB footprint question?

    Looks good to me now. I added in the ztt-resonator and added a decoupling cap of 1uF across the pic's power supply. Also added a few drill holes to mount the pcb. Cleared the traces away from C2 and cleaned up the component references, all are visible with parts soldered in. I didn't mess to...
  2. J

    Help for simple chematic

    Your gonna have to do a lot better then the above drivel if you want help. There is no schematic in your post to start with.
  3. J

    PCB footprint question?

    Olivier, I tried it again this time manually doing all the traces. I did what you said and did the bulk of my traces on the bottom. Once I ran out of avenues, I jumped to the top to finish off the connections. I have (2) GND planes. One on the bottom for GNDA and one on the top for GND. I...
  4. J

    PCB footprint question?

    Ok, few more details please. What do you means by this? They are connected. P4-1 can't be any more direct. Lost you here. Is it better to avoid the GND or VCC on capacitors and what is excepted as to close? 20mils? I would like to take credit for this design, but I can't. Where does the...
  5. J

    Impact sensor?

    Yes and they have a variety of tips you can buy. You can buy hard tips that make a tinking noise when striking cue balls. If absorption of the impact is not needed then look to buy a harder tip. I think they even have some made out of plastic these days.
  6. J

    PCB footprint question?

    Alright, well I think I finally did it. 3x2" board. The only question I have is should I separate the PGND from the SGND? PGND being the 50mil traces. edit: Instead of trying to set a ground plane on the SGND like an idiot for thermal dissipation, I decided to attach it to PGND (GNDA in...
  7. J

    PCB footprint question?

    Ok, I am getting really frustrated with this PCB layout stuff. I tried using a Ground plane to connect all my grounds, but what a crap shoot that is. I always seem to be breaking my ground plane, which would force me to connect the ground plane on bottom with a trace on top. This seems...
  8. J

    Idiotic statements from Engineers!

    Canada has vast influence from overseas. I actually hear it pronounced both ways in the US. But I certainly don't cringe and think of animals when someone says "soder". It actually has a meaning other then slang terminology and as a true blooded american I feel obligated to say it. American...
  9. J

    Idiotic statements from Engineers!

    http://dictionary.reference.com/browse/Solder Maybe because we are not idiots and actually understand pronunciation? :rolleyes: in fairness, I have only one reference, but I am assuming any dictionary will provide the same facts
  10. J

    Transistor/ current question

    The transistor released some magic smoke and saved your battery from exploding. Without a load, when the transistor conducts it creates a short between the + and - side of the battery. FYI, most people use an LED/resistor to help visualize what is happening.
  11. J

    PCB footprint question?

    Can anyone look at my footprint that created for the LMD18245. I just need a set of experienced eyes that can maybe point me to anything I might have done wrong. Datasheet: http://www.ti.com/lit/ds/symlink/lmd18245.pdf Pin 1 - Pin 15 = .700mils center to center on adjacent holes in same...
  12. J

    What software suitbale for programming robot?

    As far as I am concerned, the arduino is the best environment for new users. It has everything you need in a $30 dollar package to program the chip and to start designing with it. It has plenty of memory for programs so you don't have to be the most proficient programmer to use one. There is...
  13. J

    Amplifier circuit questions

    What knowledge? ;) An ideal opamp will have power gain of infinity. Again, in principal I understand this. The idea that you can actually amplify nothing in a perfect opamp. What that means in real world I am not exactly sure, but I know it will still be a huge gain.
  14. J

    Amplifier circuit questions

    Yep, so I am still with you. Working backwards from the designers comments seem to prove what you two have said (edited last post). I am a noob when it comes to this math relationship stuff with electronics. Right because the formula should be (1 + R2/R1) What would be a peak input voltage...
  15. J

    Amplifier circuit questions

    Thanks harald, I thought the idle current had something to do with the output. But now I understand. I got another question if you don't mind. How do they figure out the power output of this amplifier? I know the TIP125 has a Vce drop of -2v@saturation. So that means I will get a max of 13V out...
  16. J

    Capacitors

    Is it an electrolytic capacitor? These have a certain orientation, the negative side of the cap needs be connected to ground. I believe if you reverse it the capacitor has a higher internal resistance and this would explain why it drains slower. what capacitor in parallel? The capacitor is...
  17. J

    Capacitors

    Ground is your voltage reference, for there to be a voltage present there needs to be a voltage difference/potential between two points. If you never connected the capacitor to ground (or some other ref voltage) there would be no voltage difference and therefor electrons could not flow.
  18. J

    Amplifier circuit questions

    So pretty much what I thought. This is also a simple push-pull class AB amp correct? Now how do they know what value to select for the resistors connected to the base and Vcc of the op-amp? There has to be a fundamental way to mathematically calculate this value. What is it?
  19. J

    pressure sensitive plate

    This is not my idea so I have no idea if it will work. But, I remember someone telling me they had an idea to use that material you find in electronic packaging. The black foam like stuff that micro-controllers are stuck into. Put this between two plates and you should get an analog voltage as...
  20. J

    pic16f627a interface

    The micro-controller has PORTA and PORTB, both are 8 bit ports. In the code you set these to inputs or outputs. Depending on how you have this setup will determine how the external components need to be connected. Do you have code or are you just thinking of an idea?
Top