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  1. AnalogKid

    IR carrier frequency

    Was that a serious response to this OP?
  2. AnalogKid

    Stabilising wienbridge sine wave using FET

    The sinewave oscillator that started the Hewlett-Packard company used a light bulb for stabilization. Still, there is nothing wrong with using a FET if done well. ak
  3. AnalogKid

    Oneshot Timer

    The standard 555 astable circuit cannot do what you want, because it can produce duty cycles only above 50%. What you want is a duty cycle of 6.25%. This can be done with a different 555 configuration. http://www.electronics-tutorials.ws/waveforms/555_oscillator.html ak
  4. AnalogKid

    Raspberry Pi to linear actuator circuit

    Yup.
  5. AnalogKid

    need of voltage and current

    For all power supply devices - battery chargers, laptop floor-warts, industrial computer power systems, whatever - The nominal output voltage and maximum output current are stated so you can determine if they are adequate for the application. If you have a 5 V 2 A device, you now know that your...
  6. AnalogKid

    Measuring Amps, Am I Reading This Right!?

    A schematic is worth a dozen photos, but a picture still is worth a thousand words. Gimme. Also, is there a label or sticker or something on the power supply with its input and output ratings? ak
  7. AnalogKid

    IR carrier frequency

    Program for what? An oscilloscope and a frequency counter are pieces of test equipment, not apps. To determine the freequency of an IR system, you have to either have an optical detector that you can measure, or measure the signal going to the emitter. ak
  8. AnalogKid

    amplifier gain not stable

    The schematic in post #1 is a photoshopped version of a Linear Tech datasheet image. Where did you get it and where did the gain equation come from? I've never seen anything like that gain equation anywhere, ever. For the circuit in post #1, the gain is 1.212765. Note the similarity of part...
  9. AnalogKid

    Lots of transistors. What do they all do! (schematic)

    There is one differential amplifier, one dual current source with different outputs, one voltage amplifier, one active zener, one Darlington pair, and one Sziklai pair. Almost all of these have Wikipedia pages. Don't know what the intent of the Filter box is; that is where the output coupling...
  10. AnalogKid

    Raspberry Pi to linear actuator circuit

    So M2 is actuator power on/off and M1 is direction. As above, you have both FETs connected as source followers. This can work if you can supply a gate voltage that is 5-10V greater than the 5V and 12 V supplies, but you can't. Best to change the arrangement so the FETs are switching their...
  11. AnalogKid

    Variable Voltage Regulator and Pass Transistor

    The supply linked to in post #3 is less than 7 cents per watt for a single piece. That is stupidly cheap, and I do mean stupid. I wouldn't touch it. ak
  12. AnalogKid

    Digital Walking Cane

    Everything you describe already is built into your phone or your tablet. ak
  13. AnalogKid

    Variable Voltage Regulator and Pass Transistor

    Without being snotty, your preliminary approach indicates that you're probably already out of your depth. A few things... Double-converting power never is efficient, and always is expensive. At 80% efficiency, your boost converter would need to handle 100 A input current to deliver 20 A of...
  14. AnalogKid

    How to improve upon this comparator driven LED circuit?

    In that case you will have only about 1 mA through LED2. Again, there is nothing in your schematic that would cause the device output to change state because of a variation in Vcc. No input circuit, no good answer. ak
  15. AnalogKid

    4 digits digital watch Freezing last number - Is that possible???

    Your question still is not clear at all and there are no details to use to form an answer. If you search for "digital clock schematic" you will find hundreds of schematics to choose from. To make any of them do what you want, do not connect the last display digit to the clock circuit...
  16. AnalogKid

    4 digits digital watch Freezing last number - Is that possible???

    Do what?
  17. AnalogKid

    How to improve upon this comparator driven LED circuit?

    You don't give the opamp input conditions for the various Vcc conditions, so there is no clear answer. Also, what is the purpose of R1? Also, what is the need for Q? If the LM158 can sink enough current to light LED1, can't it source enough current to light LED2? ak
  18. AnalogKid

    4 digits digital watch Freezing last number - Is that possible???

    If you are asking about modifying a commercial product like the one pictured, that is would be very difficult to impossible, depending on the design. For a project built from scratch, easy. ak
  19. AnalogKid

    Multiple astable 555's

    Not the 10K resistors in series with the input, the 10K resistor in series with the opamp output. It is in the wrong place. https://en.wikipedia.org/wiki/Operational_amplifier_applications#Summing_amplifier ak
  20. AnalogKid

    Multiple astable 555's

    Those two things are not even remotely related. By your own posts, you are taking something that works and changing it to something that does not. Definitely not the same thing, but also definitely not up. ak
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