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  1. (*steve*)

    Current limiting in a CC/CV power supply

    Many commercial power supplies are linear, but switch taps on the mains transformer to maintain a sufficient, but not too high, voltage overhead to the linear regulator. Why is efficiency your first priority? Have you considered noise or transient response? What do you consider "somewhat high...
  2. (*steve*)

    Need to drain off curent.

    This thing you describe as "bleeding off current" is the two quadrant power supply I mentioned If you require power to start the downward movement (which is, I think, what you're saying) then you can insert a diode between the power supply and the motor. This will prevent current flowing back...
  3. (*steve*)

    120VAC --> 12V LED chip

    60Hz.
  4. (*steve*)

    Crimp connectors

    And for many of the crimping tools for these you'll need to make sure you can get the crimping tool over the component.
  5. (*steve*)

    ST. VN05N component

    It's very hard to recommend a Chinese knock off. There's a chance they may be ok, but there's also a chance they are cheap knock off that won't meet the original specification. There may be some suppliers still selling nos (new old stock) items which are original and this meet the original...
  6. (*steve*)

    FM transmitter hack

    It might just be best to remove all the black boxes. I note the recommended method of using wire-cutters. Also it's a great demonstration of sodering skills
  7. (*steve*)

    Multimeter Spec

    If you have one multimeter you are sure of your measurements. If you have two or more you can never be sure again. Also note that adjustment may be separate from calibration (depending on your use of the word). There are (generally speaking) three types: Calibration only Adjustment, then...
  8. (*steve*)

    need help with fm transmitter

    It calculates as 277MHz. My guess is that a factor of 10 is error is hiding there somewhere (because 277/sqrt(10) ≈ 88) Often in the really cheap circuits, the inductor is squeezed or stretched to change the frequency. My guess is that the original circuit had an inductance about 10x what is...
  9. (*steve*)

    need help with fm transmitter

    There are pages on the web which will allow you to determine the inductance of a coil of wire of a certain gauge, formed into a helix of a certain diameter and length. My guess is 1.5 turns of 0.5mm wire with a coil diameter of 6mm.
  10. (*steve*)

    Smd resistor unbelievable

    If you have a large image in terms of pixels, and in terms of space required to store it, you may be able to find a program to store the image at a lower quality. This can dramatically reduce the size without making the image itself smaller in dimensions.
  11. (*steve*)

    Help to identify markings in schematics

    I would suggest the arrows on #13 may be backwards.
  12. (*steve*)

    Help to identify markings in schematics

    Probably. The dotted lines on the first diagram show where the cables go. The solid lines between them give you a rough (but incomplete) indication of the wiring on those boards (the schematics give a more full indication). The wiring diagram doesn't make too much sense to me, especially...
  13. (*steve*)

    Project MOSFET H-Bridge to generate single phase signal

    I'd say no. From the sense that I can make of it (and it is both badly drawn and has insufficient information as to the signal sources) your mosfets will likely either run very hot, or fail.
  14. (*steve*)

    Help to identify markings in schematics

    The wiring diagram (the first image) shows which connectors connect to what other connector. In this case these are actual connectors, not pointers to offpage (or at least, distant) connections.
  15. (*steve*)

    Help to identify markings in schematics

    If it points away from the wire it's connected to then it's an output. If it points into the wire it's connected to then it's an input.
  16. (*steve*)

    What is your troubleshooting sequence?

    It's obviously important to consider what the fault is. If it's "one digit does not display" then if take a totally different initial approach to "blows fuses and makes arcing noses and emits smoke". The source is also an important distinction. Was it sitting on your workbench, and one day it...
  17. (*steve*)

    Help with power for sous vide circulation pump

    Probably. If it works, it will likely draw lower current than specified because it is running at a lower voltage. You don't need much circulation. I'd recommend that you have the inlet near a cold spot furthest from the heating element and return the flow to near the heater.
  18. (*steve*)

    How To Interface 12v 10w Solar Panel To 12v 1.3ah Battery

    No, like a 7805. The microcontroller requires 5V. Many arduinos have a voltage regulator allowing them to be powered from a higher voltage. If you're using one that doesn't, then 12V will kill it very dead.
  19. (*steve*)

    Led pinspot 2

    Yep
  20. (*steve*)

    Led pinspot 2

    You see that capacitor with the domed top in pictures 2 and 3? Replace that capacitor on all devices. Use a low ESR capacitors.
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