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  1. BobK

    PWM setup

    Note that the output of the driver is 20 to 42V. Your 4 LEDs probably require something like 12 to 16V. So it is putting out 20V, sensing too much current, and shutting down. Notice that it also says 7-12 LEDs, thus, you have less than the minimum. Why would you expect it to work when you...
  2. BobK

    when you learnt and become pro, did anything amazing happen?

    I quit grad school after passing the PhD qualifier because I was tired of being poor, taking an MS degree in computer science. And I did it during a recession. Had to move to Kansas to get a job in my speciality (compilers) at NCR Corp. Yes, they made computers. Two years later I was in...
  3. BobK

    when you learnt and become pro, did anything amazing happen?

    Somehow, I doubts it ;) Bob
  4. BobK

    bluetooth module on digital amp

    I doubt that there is anything special about that amp. Any audio amp should do. Your bluetooth module should have two outputs which connect, probably through RCA plugs into the audio amp, which connects to the speakers. Bob
  5. BobK

    mppt charge controller

    How does it change the current with a constant voltage? Are you saying the average current over the duty cycle? Bob
  6. BobK

    About PIC18F4550 programming

    Glad to be of help. Bob
  7. BobK

    About PIC18F4550 programming

    Try getting rid of the capacitor on MCLR. I have never used one myself. The datasheet says you need a 220nF cap on the Vusb pin. You might try that. Bob
  8. BobK

    Simple DC Motor setup - NEWBIE HELP!!!

    You need more than just a plug, you need a power supply that reduces line voltage to 12V. And it must be sized fir the max current that the motor draws and then some for a safety nargin. How do you expect to couple the motor to the jug? How many RPM does it need to turn at? Bob
  9. BobK

    Just a quick check of my circuit

    Yes, connecting the switch directly between the row and column. And don't forget to enable the pullups. Of course, I would try a prototype before designing a PCB. Bob
  10. BobK

    About PIC18F4550 programming

    Things to look for. 1. Have you powered all of the Vdd and Vcc pins and have decoupling capacitors (100nF) on each pait? 2. Have you pulled PGM low? This can be a problem if it is floating. 3. Is anything, other than the PICkit connected to the MCLR pin? 4. Have you tried a second chip...
  11. BobK

    Using a logic signal to switch a load

    A Bipolar transistor, a MOSFET, a triac or scr (if AC), a relay, a solid state relay. Which one you would use depends on the details of what you are trying to switch. Bob
  12. BobK

    2N2222A

    First of all, it is unlikely you have any 2N2222A’s. They come in a metal can. If you have a TO92 package it is either a pn2222 or a p2n2222, which have different pinouts. So, what exactly do you have? Bob
  13. BobK

    how to make the circuit of a wall e robot

    Not without knowing what you want it to do. Bob
  14. BobK

    Does mAh rating of a battery affect the device at the same rated voltage?

    Nitpick. I am not saying this caused your problem. You cannot always replace a battery with a higher capacity battery and have it work correctly. I replaced NiCd batteries in a drill driver with NiMH of higher capacity, but it did not work because the new batteries could not supply the needed...
  15. BobK

    Proximity sensor and SS relay

    [crystal ball] Remove the orange and white wire from the terminal marked QH and connect it to the one marked ZO. Then change jumper J2 to to connect pins 2 and 3 instead of 1 and 2. [/crystal ball] If you expect better help than that, you will have to give us some info, I don’t say more info...
  16. BobK

    Programming languages and MC selection.

    It is probably better to learn C on a PC before trying to program PICs with it. Bob
  17. BobK

    Resistance + LED works on breakboard not on stripboard?

    It looks to me like you have an LED, a resistor, and two wires, with all leads connected together. Bob
  18. BobK

    Just a quick check of my circuit

    No. First, put a pull-up on each row and each column to V+. If this can be done internally in the microcontroller, as it can on PICs, then use that, otherwise you will need to add a pullup resistor for each column. Now, to read a row, set that row as an output and output a 0. Read the...
  19. BobK

    Modifyling Electric Wheelchair Motor Control (H Bridge)

    You can control two motors from the same PWM controller as long as it can handle the combined current. Bob
  20. BobK

    Clocking an 8049 Microcontroller with Ceramic Resonator

    I don't know about that microcontroller, but for PICs, for example, you must set configuration bits correctly to choose the clock source. Have you programmed the micro with the correct configuration bits? Bob
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