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  1. BobK

    Soldering Problem

    Looks to me like the pad is gone. But the other pins nearby look like bad solder connections as well. What kind of solder are you using? Are you using extra flux? Bob
  2. BobK

    Effectively defeating PWM on Jeep Wrangler

    Easier would be to simply bypass the PWM module that is driving the headlights. It must have 12V going in and 8-12V going out. Just detach the module and wire the in to the out. Bob
  3. BobK

    I need some fresh eyes

    Hi, and welcome to E.P. "Isn't working" is a pretty vague description of a problem. Can you be more specific? And the link you posted is for a site one must subscribe to. We are not going to subscribe to a random site to look at you files. Sorry to be so negative, but your post does not...
  4. BobK

    Miniature Speaker Selection

    Can you explain a little more about the configuration? Does the speaker mount outside the box over the 35mm hole, or is the speaker inserted into the box through the 35mm hole, and hence must be smaller than that in diameter? Are you aware that a speaker with the back open has very limited...
  5. BobK

    Cheapest way to get data from multiple(100s) of sensors?

    Actually, if we take this statement literally, the multiplexer does not help as it does not read them all at once. To do that, a sample an hold is required for each sensor. At that point, I would just go to a 6-pin micro per sensor, all tied to a clock signal to start the acquisition. So...
  6. BobK

    Simple Motor Controller Circuit

    If you are using an H-bridge configuration, the body diodes are indeed exactly in the positions called for (you cannot use a diode across the motor with an H-bridge since it will see both polarities). But, you must ensure that they can carry the full motor current. Often, they are not rated as...
  7. BobK

    Cheapest way to get data from multiple(100s) of sensors?

    No, it will not be able to read proximity, the shift registers work only for digital off / on data. You need a huge analog multiplexer to get proximity readings. Bob
  8. BobK

    Kayak stand with sensors ?

    How much experience do you have? This is not a simple project. Bob
  9. BobK

    Cheapest way to get data from multiple(100s) of sensors?

    I second Harald's suggestion. Bob
  10. BobK

    Electronic Equivalent of a 3P6T 'Rotary' 3-Deck Switch

    An 8 pin microcontroller + 3 MOSFETs is what you need. You also did not need the switch you are using, a single pole 6 throw switch would do it with a few diodes. Bob
  11. BobK

    Building a current source

    I believe a typical constant current source is a PID controller, minus the I and D. It supplies a correction proportional to the error. Because the response time of electronic circuits is so fast, this is sufficient. Bob
  12. BobK

    SK Capacitor

    That is 2.6uF, 1,000,000 times larger than the 2.6pF you stated! And it makes much more sense. Look for motor start capacitors having the same 2.6uF and 400V rating. The voltage can be higher but not lower. It needs a 400V capacitor because 220V mains have a peak of over 300V. Motor start...
  13. BobK

    Help for a Project please!

    May not need a rectifier if output is DC. But it will be pulsating DC. If you want something to respond to the DC voltage, you need to smooth that, otherwise it will see a constantly varying voltage. Bob
  14. BobK

    Need help selecting a transistor for a large power load

    What is wrong with the way you are doing it now (with relays?) Transistors would disapate a lot of power and need heat sinks. Bob
  15. BobK

    Batteries in series

    Lithium ion battery chargers generally charged them in series, with additional circuitry to bypass any cell that has reach full charge. Bob
  16. BobK

    Need super capacitor voltage advice

    Basically, a capacitor is two conductors separated by an insulator. The shorter the distance of separation, the more capacitance you get, but the lower voltage it can stand without breaking down the insulation. Bob
  17. BobK

    DIY Laser Tag

    The microcontroller can do everything you want to do. To do it without a microcontroller would take maybe 10 logic chips, so the microcontroller is way simpler than discrete logic to build this. The other advantage is that all the behavior is controlled by a program that can be changed at will...
  18. BobK

    Solar yard light stopped working

    Did you charge those NiCad batteries after you got them. They generally come uncharged. Bob
  19. BobK

    tda 2003 general audio amplifier circuit

    Hi, and welcome to E.P. The size of the capacitor depends on the impedance of the circuit. A resistor and capacitor make a high pass filter. For audio, we want it to pass everything above about 20 Hz. In the input, you might have a 10K input impedance, and the capacitor that would result in...
  20. BobK

    Help for a Project please!

    But you will need to rectify, smooth, and divide down the output of the generator. Bob
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