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  1. WHONOES

    Bose wave audio System

    Try the following link. I has a number of Bose related publications. Yours may be in there. https://www.eserviceinfo.com/index.php?what=search2&searchstring=bose+wave+radio Here is another. http://www.fixya.com/search/p194741-bose_wave_radio/schematics Plus, there is a DVD available on EBAY...
  2. WHONOES

    Domestic amp keeps blowing 3.5amp fuses

    Glad you have had a result.
  3. WHONOES

    powering a cordless drill with PSU in drill press DIY build

    I doubt if your battery drill outputs anything near 500W. It's probably sub 100W and may even be closer to 50W. They get their torque by using a high speed dc motor and then gear it down a lot. I recently made a small pillar drill that uses a 30W motor and is belt driven with home pullies. It...
  4. WHONOES

    Help me in calculating base resistance for transistor

    As I have pointed out before, digital device output levels are only guaranteed to be 0.8V for a logic "0" which is easily enough to turn on a BJT. In this sort of circuit you should always add a pull down resistor to the base emitter junction to ensure that it is below the value at which it...
  5. WHONOES

    P channel MOSFET Current Flow

    Must confess, I was thinking in terms of an N channel device. That's what you get for only scanning a post. You are correct for a P device the voltage would be within 7mV of the 5V rail. The datasheet I found quoted Rds as 35mV for 4.5V Vgs.
  6. WHONOES

    P channel MOSFET Current Flow

    Surely the drain voltage will be less than the supply voltage when the Fet is fully enhanced?
  7. WHONOES

    P channel MOSFET Current Flow

    If you power supply voltage is 5V then the voltage that will appear on you Fet drain minus the forward voltage of the LED. If you include a current limiting resistor in the LED as you should if it does not have one then, the drain voltage will be almost zero.
  8. WHONOES

    P channel MOSFET Current Flow

    The LED will only draw as much current as it needs. If it is rated at 20mA then that is what it will demand regardless of what the FET is rated at. Bear in mind that the LED will need a series resistor to limit the current into it. As an example, if your supply is 5V and the LED forward voltage...
  9. WHONOES

    Video signal amplifier.

    Have a look at the following link that explains it all. https://en.wikipedia.org/wiki/Impedance_matching
  10. WHONOES

    Replace power MOSFET in subwoofer plate amp, Sledge STA-1000D

    Don't get bogged down with the Gate Source Threshold voltage. Mosfets invariably require 10V on their gates to become fully enhanced. The VGs threshold is largely immaterial in a switching circuit. They are either on or off. The driving device will be designed to accommodate this.
  11. WHONOES

    IC-socket corrosion removal

    There was a fibreglass pen around years ago for the purpose of cleaning oxide off of components, boards etc. They are still available from RS Components (just checked). Not cheap but they do the job.
  12. WHONOES

    Need help to find an equivalent SMD.

    Try the following link. It is a smd reference document. https://www.sos.sk/pdf/SMD_Catalog.pdf
  13. WHONOES

    Video signal amplifier.

    Perhaps the originator could enlighten us but hen...………………………………………….maybe not.
  14. WHONOES

    Jumper wire

    I bought the 1/2 Kg reel I mentioned some 15 years ago and it still has plenty on it. Wasn't horribly expensive either
  15. WHONOES

    Jumper wire

    I just use 28AWG enamelled copper wire that has solder through insulation. A small reel lasts a long time. It's fine for connecting components together on a breadboard anything else may require a thicker wire for larger currents.
  16. WHONOES

    Video signal amplifier.

    No. you need to match cables at both ends.
  17. WHONOES

    JVC RX-450 receiver has high impedance outputs

    Pleased you got there without too much hassle.
  18. WHONOES

    JVC RX-450 receiver has high impedance outputs

    Could simply be that the speaker selection switches are a bit oxidised and are presenting a high resistance to the speaker path. You could try cleaning the contacts and see if there is any difference after.
  19. WHONOES

    AC Laptop Adapter -> How to make 19v output into 5v?

    I would suggest using a secondary buck converter as being the easiest option rather than try to mod your regulator.
  20. WHONOES

    Silent electric motor to drive turntable.

    Sorry, forgot to add link to post #7. It explains all about how to make gears much quieter by selecting the correct type. https://khkgears.net/new/gear_knowledge/gear_technical_reference/how_to_reduce_gear_noise.html Also, using a gear train would give a form of braking by shunting the drive motor.
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