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  1. duke37

    Resistors

    3/5W I doubt if this is 0.6W. It could be either 3W or 6W, perhaps depending on size or how it is connected.
  2. duke37

    Lynx LMX4 Micro Mixer power fault

    The first thing to do to find the fault, is to get the DC voltages right, it will not work if it they are wrong. Get the details of the IC to see what the voltages should be. When measuring, make sure that you do not short two pins together.
  3. duke37

    Help with Antennas

    What is HOA? You have not said the frequency that each antenna is intended to be used for. If the frequencies are similar then there will be interactions between signals from each antenna. A resistive combiner will reduce the interaction at the cost of loss of signal. You could use an...
  4. duke37

    Lynx LMX4 Micro Mixer power fault

    I assume that the components with the prison bars are electrolytic capacitors but the values are absurd. Possibly 4.7M is 4.7µF. The amplifier and electrolytics are polarity sensitive and will be damaged if the battery is connected the wrong way round. Did you do this?
  5. duke37

    Cuchen WHK-V0620CP Rice cooker faulty

    There is another difference, the cooker was made for 60Hz whereas we have 50Hz in the UK. As far as the transformer is concerned, this pushes up the flux by 20% which may be over the top. Another transformer made for 50Hz would be the best but what would be the voltage?
  6. duke37

    understanding Ferrite Rings

    I have looked up RTV silicone. Some of these emit acetic acid which attacks soldered joints so I would avoid them. I use hot melt glue for fixing. It is quick and easy and can be removed if necessary. If you want high and permanent strength, then epoxy resin would be prefered.
  7. duke37

    Tv remote jamer

    Why should I answer your questions if you will not answer mine? You can get details of the 555, use Wikimedia "555 timer i.c." "ASTABLE". R1, R2 and R4 set the duty cycle and frequency of the output. The base voltage of the transistor should be looked at relative to the 9V (it is pnp)...
  8. duke37

    Tv remote jamer

    You can get much information on the 555 on the net. It is cofigured here as an oscillator with the frequency set by charging and discharging C1. The output is pin 3 and this changes from 0V to 9V. When it is low, current is passed through the two diodes so giving about 1.2V at the base of the...
  9. duke37

    Grounding question

    Ground is ground is ground. You should avoid ground loops since the loop can pick up electromagnetic energy and give different voltages around the loop. This is a common problem in audio equipment where the voltages are low so giving mains hum. To avoid this, select a central common point...
  10. duke37

    can anyone tell me what part is this???

    What is an HW? I have not seen these symbols before with the squiggles. 1. A capacitor , possibly variable. Normally the capacitor has an arrow through it for variable or a long T through it for preset. 2. Light sensitive resistor? 3. Light emitting diode? 4. Light sensitive npn...
  11. duke37

    understanding Ferrite Rings

    When you have learned about ferrite rings, you can teach me. Ferrite rings are used to suppress voltage/current transients. They will be inportant in RC flying since the transients can be radiated and affect the radio signals. The sound that you hear will come from some component which is...
  12. duke37

    Want to on and off solanoid valve using MOSFET

    I looked up the data on the IRF540, It has a threshold voltage of up to 4V and will need at least 6V to turn it on, depending on the current needed.
  13. duke37

    wiring of AC speed motor control

    The module can be used with a universal (AC/DC) motor or a DC motor with a rectifier. I do not think your motor is suitable for speed control.
  14. duke37

    Want to on and off solanoid valve using MOSFET

    Have you checked that 4.5V is sufficient to turn on the FET fully? You could switch a Darlington BJT and not use a relay.
  15. duke37

    wiring of AC speed motor control

    An induction motor is an inductive load. A capacitor start induction motor uses a capcitor in series with a starting winding. This is disconnected when the motor is up to speed. If the motor does not get up to speed then the capacitor will not be disconnected and will be overstressed. An...
  16. duke37

    Two garage doors from one switch

    I can't think of a way. There will either be two transmitters (unlikely) or two coded pulse sequences sent. Two transmitters on nearly the same frequency will interfere with each other, Two codes cannot be sent simultaneously.
  17. duke37

    Need help with a PSU schematic

    I have not been following this extesive thread but I see that the diagram in #126 rectifies 250V, smooths it and only gets 170V. It is more like double this.
  18. duke37

    wiring of AC speed motor control

    I do not think this controller is suitable for an induction motor. It looks to give a phase angle control. Funny things can happen with capacitive and inductive loads. The examples given are for series wound (universal) motors or resistive load.
  19. duke37

    Step-down transformer suddenly stopped working - but why?

    If you know the correct voltage (24V ?) then get a cheapo transformer and tack it in to test the rest of the circuitry. If that works then look for a transformer to fit or get the original rewound. I have never been able to repair a primary with a thermal fuse. Wall warts are subject to...
  20. duke37

    LM317T and how it works

    I believe that the connections as shown in #11 are correct when looking at the labeled side of the LM317T. The output is the centre leg in any case. Solder can be removed by solder braid, you can even use the braid from the outer of a co-axial cable.
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