Search results

Search Forums New Posts
  1. BobK

    Need help with prototype.

    [wild guess mode] To produces 100, maybe $100 each. To produce 1,000,000, maybe $2 each. [/wild guess mode] Bob
  2. BobK

    Not fully understanding the inductor

    Yes, that would be correct. Bob
  3. BobK

    PIC Hex Files

    You cannot program the RAM of a PIC in the .HEX file. The EEPROM and program ROM are in the same address space, so no conflict. Bob
  4. BobK

    Need guidance; newbie project - LED controllable steps

    I see no reason this could not be done with a single microcontroller. It sounds like you need 12 inputs and 12 outputs. A 40-pin micro should give you plenty of extra pins. Bob
  5. BobK

    Starting a new project, a smartwatch

    Learn how to program. I would suggest that you start with C programming on a PC. You do realize that Apple, with all of its resources, has been working on this for years? Do you expect to be able to match what they come up with? Bob
  6. BobK

    Please help with flyback current protection

    A flyback diode is placed across the winding with the opposite polarity that it is driven, i.e. the cathode goes to the positive side and anode to the negative side of coil. If you are indeed using a H-bridge to drive the solenoid both directions you cannot use that configuration. In this...
  7. BobK

    Woo-Woo Power saving speculation

    You seem to have the misconception that amps determine power. No, amps * volts = power. If you reduce voltage from 240 to 12 you can get 20 times the amps (minus some losses) but the power is the same. If you bump the 12V back up to 240, you will get 1/20th the amps and again the power is the...
  8. BobK

    this bugs me / noob question`

    You turn up the current slowly unitl it pops and then reduce it by a factor of 2. Do this with each of your LEDs, then you will have to buy new ones, and you will know their specs. Bob
  9. BobK

    noob needs help

    3 supplies is a little extravagant, 2 should have done it. With dual supplies + and -, you can use a half-bridge in place of an H-bridge, which is what I expect you built with your 2 relays. An H-bridge allows you to send either polarity to the motor with a single supply. Bob
  10. BobK

    power loss/heating question

    Electrons bound to molecules. The electrons carrying the current are free electrons. The amount of free electrons are what makes something a conductor. Bob
  11. BobK

    Conditionally Allow A Bridged Circuit

    Usually this is done with a pin strip header with 2 pins and a shorting block that can be easily placed or removed. Bob
  12. BobK

    Building a LED driver

    You cannot have a fixed voltage and a constant current at the same time. LEDs are current driven devices. They are best driven by a constant current source, which will adjust the voltage automatically to get the desired current. One of the simplest ways to do this is with an LM317 voltage...
  13. BobK

    Starting a new project, a smartwatch

    To program this from scratch is a HUGE project for an experienced programmer. I would suggest that you start with something a lot simpler. Bob
  14. BobK

    noob needs help

    You need an H-bridge. The trick with open-collector outputs is that they can only make something low. When they are set to high, it is like and open connection (hence the name). So if you want to a signal to go high and low, you need a resistor from a positive voltage connected to the open...
  15. BobK

    Converting PWM output into a voltage using low pass filter.

    Motors are typically driven by a PWM without filtering it to produce a constant voltage. Is there a special reason this will not work for you? Bob
  16. BobK

    Problems with DC to DC converter

    Give us more information than that. How about a schematic for starters? And what is the load? Bob
  17. BobK

    Creating Theater Magic

    I don't understand why two circuits are needed. Why can't you simply have a single photocell that turns on the street light when it sees light? (with it positioned so the street light itself does not illuminate it) Bob
  18. BobK

    PCB tips...

    You can make a ground plane out of the copper on the PCB. Typical PCB design software will allow you to mark a rectangle as ground plane, and then will separate any traces from it automagically. Bob
  19. BobK

    power loss/heating question

    Electrons are moving through the wire. They bump into things, losing electrical energy and creating heat energy by making the things they bump into move Bob
  20. BobK

    Retractable Toy Hatchet Mechanism

    What does this have to do with electronics? Are you taking about an axe that is an autonomous flying robot? Bob
Top