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  1. duke37

    Op-Amp Help

    In #13 the circuit is hidden but it looks as if it is a virtual earth amplifier. If the output clips, the amplifier cannot work properly. The only part of the waveform which is correct is that at the crossover positions.
  2. duke37

    Op-Amp Help

    Try 4mV in rather than 4V and see what gain you get.
  3. duke37

    5 decade old battery pack bridge

    Why not answer the questions you were asked? mAh is not a measure of power, this is W. Get the units right and do the calculations.:)
  4. duke37

    Wiring a Bathroom Light

    The data you show means the light needs a line and neutral connection. No mention of ground. All lights must have an earth wire by law. Any moifications in a bathroom must be done by a qualified electrician. Get the job done by a qualified electrician and get a receipt.
  5. duke37

    Soldering High Amperage Transistors

    Zinc is difficult to solder and is soft to but what part is made of zinc? Iron is galvenised for roofs and zinc is sometimes used a a substitute for lead flashing. The parts you show in the pictures appear to be either copper or brass which are tin plated and should be easy to solder given...
  6. duke37

    +/- 15 volt dc power from battery

    You need more data. I suggest that you use four 9V batteries and a 7815 positive regulator and a 7915 negative regulator. The batteries must be big enough to provide the current.
  7. duke37

    5 decade old battery pack bridge

    Why do wish to use 1N295 diodes, they are germanium, only 40V 50mA. These will fail or be damaged if there is no load on the charger. What is wrong with !N4007 silicon diodes, 1000V 1A. Much more robust and very cheap. Do you drive a Ford model T? I suggested that you calculate the current...
  8. duke37

    Wiring together LED lighting for a display

    I have not checked the calculations but 26Ω should be replaced by 27Ω, a standard value 0.5W or bigger would do. 98Ω could be replaced by 100Ω 1/8W.
  9. duke37

    Passive Frequency Filter with Cut-off negative part of the sine wave

    A clipped sine wave will contain a lot of harmonics. The filter will select some of them. If this is audio, it will sound ORRIBUL. You could simulate it in LTspice.
  10. duke37

    ISO a particular switch. Don't know what it's called/to look for

    Most animals have four legs and if these are not connected to identical voltages then large currents can flow. A faulty 11kV mains transformer put a voltage gradient in the ground. The sheep did not seem to mind until they were touched with a shearing machine but the dog would not come near. He...
  11. duke37

    How To Control Amperage In A Breadboard ?

    Neither was your answer helpful. You will need to say what you want to do. You can only convert 2A to 2.5A with less voltage or with more power as Edd says. AC or DC? What frequency? What sort of stability? Will a breadboard take 2.5A? Say what you want to do.:)
  12. duke37

    5 decade old battery pack bridge

    I would not use the 1N60 diodes, if I remember rightly they are germanium and low voltage. You could look up the data. If there is no load, the diodes are subjected to the full mains voltage. 1N4007 diodes (1000V, 1A) are readily available and very cheap. The current and voltage could vary...
  13. duke37

    555 RC voltage rating

    Seven octaves? The frequencies seem to be a factor of two between each. Generate 4672Hz with your 555 and then put into a digital divider to get the other frequencies.There were dividers for organ frequency generation to do this.
  14. duke37

    Solar panel.

    If the motor struggles to start, then it is not getting high voltage. I have a digital meter which shows high readings when the meter battery voltage is low. I often use an analogue meter (without battery) for such conditions. Digital meters can be affected by AC fields.
  15. duke37

    AC current help

    You will need to get relevant data. Resistance, inductance, power factor, frequency etc Get a welder power supply.:)
  16. duke37

    5 decade old battery pack bridge

    C1 sets the current. Why did it fail, is the capacitor faulty? 1N4007 could do. The circuit is not isolated from the mains so is dangerous.
  17. duke37

    Simple voltage multiplier help

    The open circles are input, the closed circles are output. You will not get significant current out but then you do not need much. The 1N4007 are reputed to be quite slow but I cannot confirm this. I have seen it said that lower voltage diodes in the same series are faster. You could try...
  18. duke37

    ISO a particular switch. Don't know what it's called/to look for

    The picture shows a three terminal change over switch. The common terminal is tucked underneath and only the edge can be seen. I have never seen a two terminal microswitch but then I have not seen many types.:) The terminals on this size of switch will be quarter inch Lucas connections, you can...
  19. duke37

    Help Identifying This Part

    Looks to be part of a relay to me. Show an overall picture and give an indication of what it does.
  20. duke37

    Lenco 600 Transformer identification

    There is some correlation. A 6V amplifier would have difficulty in producing a watt. The operating voltage is often chosen to use easily available devices so 100V(+/-50V) is about the maximum for a domestic amplifier using 4Ω or 8Ω speakers. Many years ago, I was told that electric motors...
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