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  1. duke37

    Trying to identify and locate component or suitable replacement

    There are some components shown on the diagram which are shorted. I think these may be optional and, if used, the links should be removed. There are lots of connecting points which are not used. I would suggest that M522C is not fitted and so would not cause a short.
  2. duke37

    whats the best way to wire 40 SLA batterys in parallel

    I have a capacitor box out of a transmitter. A couple of dozen electrolytic capcitors were connected with individual wires to the output terminal. One of the wires had melted presumably due to a faulty capacitor. I suggest that you connect each battery to a common bus with a fusible wire which...
  3. duke37

    how to make a non linear load setup for ups testing

    It is not clear what you wish to do. What is the purpose of the diode and capacitor? Capacitors are expensive to pass considerable current at 50Hz. For a load, I would use one or more 1kW radiant fire elements. You could also consider an electric motor with a water cooled brake.
  4. duke37

    4V, 0.5A BATTERY CHARGER

    4V is very unusual. Does it have two cells? A 12V car battery is charged to the top 14.4V so 2.4V per cell. 2.3V per cell will do for maintaining a reserve battery which is not normally discharged. Voltage regulator chips often have a 1A current limit.
  5. duke37

    T3J81 (Zener Diode ?)

    Variac is a trade name of products made by Claude Lyons but is often used for other variable transformers such as Regavolt. It enables you to obtain a variable voltage from the mains so could use a battery charger to excite the alternator at different levels. The idea is to separate the...
  6. duke37

    T3J81 (Zener Diode ?)

    The tractor shown is a Nuffield Universal petrol/TVO.(Morris Motors). It was produced in the 1950s with 5 speeds and electric starter and was a vast improvement on the 3 speed Standard Fordson. It was developed over the years and was taken over by Marshal, then abandoned. The Field Marshal was a...
  7. duke37

    T3J81 (Zener Diode ?)

    The way I have tested 'surplus' diodes is to use a high voltage supply and measure the voltage of this with a meter. Interpose the diode to see the amount of voltage drop. I used a meter with an input resistance of 1M which limits the current, I went up to 1000V for high voltage diodes - you...
  8. duke37

    Solenoid energized indication

    Put the led in series with a 1k resistor across the solenoid supply. Get the polarity right. If you are not sure, then use another led connected in inverse across the led. One led will light, remove the one which does not.
  9. duke37

    T3J81 (Zener Diode ?)

    If the diode is faulty, it would likely show the same connection in each direction, either open circuit or short. Some information on the generator may help. Three diodes side by side may be rectifying three phase from the alternator. I woukd guess that Colin #3 is correct.
  10. duke37

    Can it damage IC if connecting two speaker in parallel in output?

    That is what I quoted. Measure the voltage that you have in reality and see how it varies as the volume is changed.
  11. duke37

    Can it damage IC if connecting two speaker in parallel in output?

    The recommended load for the STK 4231 is 8Ω but to get the output you need a power supply of +/-51V. Do you have this?
  12. duke37

    Equipment. Curious about experiences.

    The batteries drive the meter only when measuring resistance. Digital meters use batteries for all readings.
  13. duke37

    Quality testing of an electronic item

    What do you mean by quality? There will be miriads of requirements and will need a specification for each.
  14. duke37

    Diode

    It would help if you gave information on the model and year of the Aga. A photo of the entire board, both sides may enable someone to deduce the purpose of the diodes. Are you sure the diodes are faulty. They are covered in dried gravy.:) If they are connected to a transformer they could be...
  15. duke37

    Strange node Notation (clear circle)

    The nodes are numbered. I would think that this is where a voltage can be acessed. There will be a connection between R1 and R2 and a connection between Q9 and Cext
  16. duke37

    Brain tester.

    No, not without a great deal of complexity and expence. Get her to fit the proper cable.
  17. duke37

    How connect AC motor to mains?

    It looks as if the capacitor is connected to the brown and red wires. The black wire is common (neutral) and one of the others is for the live feed. I do not know the type of motor but it is likely to be some kind of squirrel cage motor. The speed may be controlled by altering the leakage...
  18. duke37

    Battery Chemistry

    Ferrite is an iron based compound (spinel?) but can also contain other elements to optimise the magnetic properties. It is made with a very high resistance to reduce the Eddy currents in an alternating magnetic field. You will not be able to use it as a battery electrode.
  19. duke37

    I need help indentifying a component for an old CRT TV

    I have had another look at your photo. The capacitors that I suggested you replaced have been marked with a red blob. Another capacitor is also marked. Who did this, have you had someone looking for faults? Does your electrician know about electronics?
  20. duke37

    I need help indentifying a component for an old CRT TV

    If the electricion does ot know what it is, how does he know it is faulty? I think it is a ferrite cored transformer in the power supply. Probably not faulty. To the left of the picture are two fat capacitors. These are intended to smooth the rectified mains. One of the capacitors has a domed...
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