Search results

Search Forums New Posts
  1. BobK

    New projects

    I would suggest an untied shoelace alarm, with bluetooth interface to a smart phone. Bob
  2. BobK

    Usb trigger for 12v TV backlight

    IRF520 requires 10V to turn on fully. It might work at 5V, but typically cannot pass more than 2A at that gate voltage, and will be dropping between 1 and 2V at that current. You need a logic level MOSFET like the IRLZ44. Bob
  3. BobK

    Sensor choice for pond water depth

    Yep, my pond has a mechanical float based auto-fill valve. Bob
  4. BobK

    Help with increasing the power of a Philips hue bulb Frankenstein "hack"

    I am still cofused about what you are trying to do. The Hue bulb allows you to change the color and brightness. One SSR is not going to do that. At best, you would get on / off control. Is that what you are expectinng? Bob
  5. BobK

    Need to abort a 555 1-shot timer with same pulse that triggers it

    It depends on where you are starting. I am a software engineer and electronics hobbyist, who had not done anything with microcontrollers before, and I was able to program PICs with a PICkit 1 on the first day, and had built my own NiCad charger on stripboard within a week. And PICs are way...
  6. BobK

    Help with increasing the power of a Philips hue bulb Frankenstein "hack"

    What was the signal originally connected to on the Phillips bulb? I can't think of any reason whe they would have a 3.3V signal out of the controller board. Have you neasured it? If the SSR is being energized when the bulb is supposed to be off, I submit that the signal is not what you think...
  7. BobK

    Help with increasing the power of a Philips hue bulb Frankenstein "hack"

    What is this 3.3V output? I thought you were using the output from the controller board to the LEDs. That output is likely to be in the range of 30 to 100 V and it would be a PWM signal, which is not appropriate for controlling an SSR. Bob
  8. BobK

    Consumption of a Led Matrix

    You could, just barely, use strings of one of each color to run off 9V. Then the resistor would be (9-3-3-2) /0.020 = 50Ω. Bob
  9. BobK

    Need to abort a 555 1-shot timer with same pulse that triggers it

    Thats is a bit pessimistic. I think most people with some electronics experience could learn enough about Arduino for this project in a matter of days. Bob
  10. BobK

    9v Guitar Amp w/out LM386

    Nice, but does it go to 11? Bob
  11. BobK

    Need to abort a 555 1-shot timer with same pulse that triggers it

    I think the RC delay is probably way too large. Actually, not sure why it is needed at all. Bob
  12. BobK

    How to wire up this ssr i have

    The in1-in4 inputs are connected to the positive of the signal driving them. And the assumption is that DC- is the negative for all of them. Bob
  13. BobK

    Transceiver Circuit

    They are whereever you put them. Bob
  14. BobK

    Transceiver Circuit

    Are you talking about the position of the components in the scematic, or the position in the circuit when built? Bob
  15. BobK

    3D Printer Thread

    Yep, always go for the twofer when you can :) Bob
  16. BobK

    Transceiver Circuit

    You realize that a schematic has nothing to do with the placement of the parts, right? Bob
  17. BobK

    12V-5V converter

    In a buck converter, the heat is dissipated in multiple components, not just a single pass transistor, so it is easier to manage. 3A without a heat sink should be quite doable. Bob
  18. BobK

    3D Printer Thread

    But if I bought a machine for its 3D printing capability, it would be nice if I could also use it for making PCBs. What is 3D printing, but laying down 2D layer over 2D layer? I would be looking at using a different type of nozzle., of course. Although, using plastic filament with a narrower...
  19. BobK

    3D Printer Thread

    Well, here is a question for you. Would it be difficult to use a 3D printer to squirt resist ink onto a PCB? Are such nozzles available? It seems like the highly accurate positioning these things can do would work very well for making PCBs. Bob
  20. BobK

    MAX883C/D (Just because!)

    I guess that is the kind of thing people put under the black rounded blobs on PCBs. Bob
Top