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  1. ramussons

    Trans former rewind

    Wind about 20 turns of 22 gauge enamalled wire through the gap. Measure the voltage. That should give an idea of how many turns are required for 10 volts. Add 2.5% more turns. Hope there's enough space to wind the required turns. Take care when pulling the wire through the gaps so it does not...
  2. ramussons

    Help identifiying these burnt resistors

    It would help more if we get an idea of where these resistors were in the circuit. Can we get a photo of the PCB where these resistors were? And the corresponding Track side if possible.
  3. ramussons

    Tecsun R9700DX Multiband SW Radio goes blank

    Could be a band select switch problem. They don't last long if used frequently.
  4. ramussons

    Need help finding power supply

    Long story too short. :D To what does the power supply belong to? Those transformers very rarely fail. Check that switching transistor / IC mounted on the heat sink between L2 and C43.
  5. ramussons

    Laptop won’t turn on, short circuit?

    Maybe he has headphones with DIN plugs. And plugged it into a (very very) old motherboard Mouse connector... If I recall correctly, those old boards would not turn on without a keyboard connected.... And the Keyboard wont come on because the power feed blew thanks to the phones.....
  6. ramussons

    Green picture from scart

    Additionally, do all the monitors have a RGB option? Maybe the working ones choose Composite irrespective of the Pin 16 status.
  7. ramussons

    Green picture from scart

    The SCART connection handles both RGB and Composite video; Pins: 7 Blue, 11 Green, 15 Red 19 Composite OUT (video source), 20 Composite IN (Monitor). 16 RGB or Composite select (decided by the video source) What is (are) your Monitor(s) selecting? RGB or Composite? Let's say that for the VCR...
  8. ramussons

    Green picture from scart

    If the problem is only with a particular display, the problem is there. Check the SCART connections (though unlikely), pins 7 and 15, the Blue and Red signals. The problem could be the Red and Blue signal amplifiers.
  9. ramussons

    3-phase 380V inverter with EGS031 and EGP3000W boards

    Does this help? I have some info on the egs002, but its 4 Mb and its here: https://we.tl/Qp7xBUFKa3
  10. ramussons

    Green picture from scart

    If the output is set to RGB, where does the SCART come in?
  11. ramussons

    Tinkering with my stereo

    Model? Schematic? Photos? .... would be highly welcome for suggestions from members...
  12. ramussons

    Variable current power supply with varying duty cycle

    I think these are 2 different projects. The power supply is one and the "duty cycle" will be an oscillator with adjustable duty cycle, which in turn drives a "driver" or "bridge". Is your "power supply" to give a fixed power pulses or free running ?
  13. ramussons

    Battery monitor question

    Waiting for the schematic...... Meanwhile, if the Zeners are in series, why do you need a current limiting resistor for each zener? Why not use a LM 3914? It's much simpler and flexible. https://www.electronicshub.org/battery-level-indicator/
  14. ramussons

    Is this something fixable?

    The 2nd photo shows that there is more damage, a overheated / burnt resistor, PCB, .....
  15. ramussons

    Multivibrator of varying frequency

    When Q2 is in Saturation, C3 has to charge thru' R2 to finally switch on Q3. When Q3 is in Saturation, C2 has to charge thru' R3 to finally switch on Q2. R2 and R3 control the charge timing and hence the frequency, not R1 and R4 If the hFE of both Q2 and Q3 is same, yes, Q3 turns on first.
  16. ramussons

    What are real example of " While Loop"

    Its good practice to include a "break" statement to exit from the "while loop" routine without having to power off. while(......) { do the following . . {if (.............) break } }
  17. ramussons

    It’s time for consumer Electronics Manufacturers to label their transformers!

    Why not label the Wall Wart the moment it is received with its device. I do it and there is no confusion later.
  18. ramussons

    Have been given a disassembled Whirlpool grill-microwave oven with missing decals & fuses?

    As long as the Hi Voltage fuse is not in circuit, you can connect a 100/250 watt incandescent bulb in place of the main fuse to do the testing. Saves on Fuse replacements.
  19. ramussons

    Electret Microphone Help

    An Amplifier is needed for the microphone to drive the speakers. Have you used one? Can you give a schematic of what you did? Google for "simple FM transmitters" and you will be flooded with schematics.
  20. ramussons

    LED setup help needed.

    You can make a circuit using 8 D Flip Flops. The clock will be the switch. At each click, the output of the D Flip Flops can be Hi to light the LED's. At the 8th pulse, the Output of the Last FF will Reset all to Lo. An 8 bit Shift Register is also a possibility. But unless you know some...
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