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  1. AnalogKid

    Light sensor motor control

    IF IF IF the sensor output is *not* switch contacts, then: Capacitor-couple the sensor to the Threshold input. If the light sensor is high when the circuit is reset, it will have to go low and then high again to set the latch. You can leave pin 7 open. ak
  2. AnalogKid

    modify press-on-press-off to high current

    2. If by low frequency you mean that it takes too long for the circuit to reset itself for the next button press, decrease R1 and R2 to 47K each and see how that works for you. 1. Check the 5551 data sheet for continuous collector current, and compare that to the calculated collector current...
  3. AnalogKid

    create circuit for on and off on second press only

    Both operation sequences are fairly easy to achieve without a controller, using simple logic chips like gates and flipflops. Of the two operations you described, the second one is much easier than the first. In text mode, it is a debounced switch clocking a toggle flipflop. If the switch is...
  4. AnalogKid

    Electronic Circuit error

    No, there isn't. The image in post #1 is not a schematic. It appears to be a wiring plan for a prototyping or perf board, but it is lacking a lot of information. It has two large and many small rectangles with no clue as to what any of them are, let alone their values. Please post a...
  5. AnalogKid

    Electronic Circuit error

    A 7812 has three pins. There are six possible ways to connect them, and five of those are incorrect. Please post a schematic with pin numbers so we can evaluate your circuit. ak
  6. AnalogKid

    Blocking DC voltage on an AC circuit

    You will get a lot of help here, but ... I suggest you rethink this business plan. Not trying to be snarky of defeatist, just warning you of a serious potential problem. And, still not enough information to determine where the mysterious DC is coming from or how it is damaging a power line...
  7. AnalogKid

    Blocking DC voltage on an AC circuit

    Can you share more information about this? Are these power transformers or small signal? In what way is the DC component "damaging" the transformer? Can you share the schematic that includes the transformer so we can see it in some context? ak
  8. AnalogKid

    Simply Sunday afternoon project turned nightmare!

    I don't have apple devices. From what I've seen, most of the charger brains are inside the phone, not the wall wart, so defeating this "feature" will be difficult. ak
  9. AnalogKid

    Forcing Capacitor Bank to Act as Harmonic Filter

    If a high-rise building with air conditioner motors, refrigerator motors, washing machine motors, dryer motors, and a butt-load of fluorescent lights has a power factor of 0.95, I'd call that a miracle and not do anything. ak
  10. AnalogKid

    Need help on 8 current sensor signal to RS232 signal to read by controller

    You will need more than one line. If the eight 5V circuits are analog, then you need an A/D comnerter since you say your controller has a digital input. You can have 8 A/D converters, or one converter with a 8:1 analog multiplexer in front of it. either way, you have to know how many bits of...
  11. AnalogKid

    Resistance + LED works on breakboard not on stripboard?

    On the second, topside image with the components, you need to indicate which direction the copper strips are going underneath. For example, no matter which way the strips are running, the top end of the resistor does not contact anything else on the board except its own other end. ak
  12. AnalogKid

    Equivalent Circuits

    Math check. ak
  13. AnalogKid

    New idea for oscillator

    I think that's a good plan. What you described is incorrect in so many ways... No fear of that. ak
  14. AnalogKid

    New idea for oscillator

    No, it isn't. You are (very poorly) trying to describe a multivibrator circuit, but that is only one type of oscillator out of dozens. "it goes ..." - What is "it"? And, what is "pinging"? ak
  15. AnalogKid

    Led electronic clock kit

    This type is switch is symmetrical. It can be turned 180 degrees and still will work in the circuit. ak
  16. AnalogKid

    555 timer

    Another way to go is with one 2N7000 or 7002 MOSFET and nothing else other than the R and C. No schematic capability right now, but here is the circuit: R (2.2 meg) and C (1000 uF) in parallel from transistor gate to GND. Switch from gate to Vcc. Source to GND Drain to LED to resistor to Vcc...
  17. AnalogKid

    Timer for laundry machine

    Are T, T1, T2, and the time the finish signal is on adjustable or fixed? I suggest renaming them T1 to T4. ak
  18. AnalogKid

    555 timer for a fan

    Can you post an updated schematic? ak
  19. AnalogKid

    Voltmeter ideas

    I think that might be less accurate. An LM324 with 5%, or even 1% resistors in a standard diff amp config will be less accurate than his pot and voltage follower when adjusted with a decent 3-1/2 digit meter. Note that the adjustment tweaks out the 324's input errors, there is no gain error or...
  20. AnalogKid

    555 timer for a fan

    Change to a CMOS 555 - LMC555. 98% less idle current. The circuit in post #8 seems overly complex. I suggest going back to post #3, configure the output transistor as a saturated switch as in Q1 in post #6, with the fan in the collector to Vcc. With the CMOS 555, off-state energy is about...
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