Search results

Search Forums New Posts
  1. AnalogKid

    delay on timer

    Based on the part number, your LED has no internal current limiting. If actually true, the only reason it hasn't failed is that the battery voltage is so low. You can increase the circuit's output current capability by adding a small, n-channel, power MOSFET between the 555 output and the...
  2. AnalogKid

    delay on timer

    Probably because the LED draws less current than the laser. Note that the laser overloads the 555 output stage. If you want a better answer, consider providing enough information to form one. LED make LED part number LED voltage LED current LED current limiting ak
  3. AnalogKid

    delay on timer

    Datasheet - front page: "Output can source or sink 200 mA." ak
  4. AnalogKid

    delay on timer

    The NE555, and the LM555, which is National's copy of the NE555, are rated for operating voltages between 4.5 V and 16 V. Source: datasheet ak
  5. AnalogKid

    Old School Bell reloaded

    You should start your own thread, with a link to this one for reference. Missing from the *entire* previous thread was a schematic. A sketch of the components and connections (with reference designations) will be a great help. Nothing fancy, just enough so that we can discuss things...
  6. AnalogKid

    Single 3.3V Inverter

    Could work. Post a schematic to be sure. ak
  7. AnalogKid

    Single 3.3V Inverter

    The mere mention of a 741 will bring down a plague of locusts from some members. their "passion" not withstanding, they are correct in this case. A 741 will not perform this function with the power sources you have available. This will: One NPN transistor as an inverting saturated switch...
  8. AnalogKid

    How to choose this PNP transistor

    The schematics are completely unreadable. What are the functions of the two circuits? What is it you are trying to achieve? Think. How are we supposed to advise you about selecting a transistor when we do not know the current through it or voltage across it? the link you posted goes to a...
  9. AnalogKid

    Question on reversing polarity for DC Motors #2

    This thread is over 2.5 years old. To ask your own question, start a new thread. You can have a link to this thread for reference. ak
  10. AnalogKid

    Jacobs ladder help

    Post a close-up image of the top of the coil. It looks like there might be + and - markings molded into the plastic near the threaded terminals, but it is hard to see. If yes, then follow the instructions you posted. In the schematic in post #2, the lower red wire goes to the insulated center...
  11. AnalogKid

    2 mosfets switch

    1-transistor inverter, CMOS inverter, TTL inverter, etc. What is the circuit voltage? What is the switched current? How fast do the output currents need to turn on / turn off? ETC. ak
  12. AnalogKid

    Need to generate a 1kHz square wave with amplitude +12v to -12v

    Way to bury the lead. No "standard" opamp can supply anything near that voltage and current. A power opamp from Apex or Burr Brown can, but they are expensive. I have a circuit somewhere, from another thread. ak
  13. AnalogKid

    Need to generate a 1kHz square wave with amplitude +12v to -12v

    How much output current do you need? What is the +/-12 V signal driving? Do you need a fast rise or fall time? Depending on the answers, this might be done with a 2-transistor booster stage driven by the 555 output. ak
  14. AnalogKid

    Audio emitter resistor

    Please post a photo of the resistor. ak
  15. AnalogKid

    Curious guys

    The battery is protected from non-ionizing radiation, and from CIA thought control programs. ak
  16. AnalogKid

    Power switch for commercial citrus juicer

    Not at all the same. A looks like a circuit breaker with a remote-trip solenoid built-in. B looks like a switch and relay combination for a specific, but unknown, application. C is an actual on/off switch. You need to figure out what kind of switch your application - and your country's...
  17. AnalogKid

    Requesting Ideas for my Next Venture

    If you connect the LED correctly, the standard 555 astable circuit will produce a constant LED on time (blink/flash) and a variable off time (metronome period). According to Wikipedia, "A metronome's tempo typically is adjustable from 40 to 208 BPM." That's a 5:1 range, easy for a 555. 555, 3...
  18. AnalogKid

    Power supplies

    Convention. A fully isolated, single output, DC power supply, adjustable or fixed, has no external reference. Therefore, it is equally acceptable to connect the + output or the - to the Ground of whatever it is powering. Two identical 12 V supplies (again - fully-isolated) with the + from...
  19. AnalogKid

    Transistor XOR gate

    At the start, S1 and S2 are open, Q1-Q4 are off, the base of Q5 is floating so it's off, there is no base current path through Q5 for Q6 so it's off, and the LED is off. For XOR inputs = 0,0, the output is 0. Note that if there were any Q5 emitter current, it has a two paths to GND, through Q1...
  20. AnalogKid

    555 continuous timer

    What does the datasheet say? ak
Top