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  1. crutschow

    Resistor wattage confusion

    1.2W still must be dissipated no matter the rating of the resistors, so they will get hot. If they are heating a close-by transistor, then you might mount the resistors with long leads above the board so they are not so close and can more freely dissipate the heat.
  2. crutschow

    CD4017B has the jitters

    That relay module has a built-in transistor driver with a diode across the coil, so you just have to apply power from your battery and directly connect the output of the CD4017 to the control input, no added transistor needed.
  3. crutschow

    CD4017B has the jitters

    The PULSE command determines the characteristics of the signal generated by the voltage source (generator) V1 (here a 4V to 0V pulse that's on for 5ms with a 10ms period, 1µs rise and fall times, for 10 pulses total, and then stays at the initial voltage (4V) for the rest of the time). That...
  4. crutschow

    CD4017B has the jitters

    Not likely, unless it's a really large relay. The diode only has to carry the relay coil current for the short time it takes to dissipate the coil inductive energy so, unless that current is above the peak current rating of the diode (500mA for the 1N4148), I don't see a problem.
  5. crutschow

    electronic Tesla valve (ETV)

    It does matter if the circuit is messy if you want others to understand it. Otherwise you can wallow by yourself in your vast confusion.
  6. crutschow

    Are some capacitors LOW ESR????

    We seem to be replying to a ghost post, which has apparently been removed.
  7. crutschow

    Checking Capacitor

    Do you mean "diode test"? A good capacitor will look like an open circuit with a resistance check. You can use a resistor (say 1 megohm) in series with the capacitor and charge it with a DC voltage to check the RC time-constant to see if it's good. Why do you think it's bad?
  8. crutschow

    please i need a mentor to guide to learn how to make basic electronic circuits especially led emergency lights, mobile phone chargers, laptop chargers

    Why do you want to learn how to make devices that can be readily purchased? You need to start leaning basic electronics before you can design those items, so find some tutorials for that. Also learning how to use a SPICE simulator, such as the free LTspice from Analog Devices, can help you...
  9. crutschow

    Use speakers with AV receiver

    An amp will always work with speakers that have a higher impedance, since the output current and power is reduced. And I see no problem with the higher power rating of the amp since the power with 4 ohm speakers will be 750W. Given that rating, it wouldn't surprise me if both amps are actually...
  10. crutschow

    CD4017B has the jitters

    And you definitely don't want the circuit ground to be connected to the AC ground, as that's a serious shock hazard. That's one purpose of the relay, to isolate the control from the output. You should be able to eliminate the multiple switching by connecting a large capacitor (try 470µF or so)...
  11. crutschow

    Are some capacitors LOW ESR????

    They are sold as low ESR types and it is specified in their data sheets. Why all the questions marks???????
  12. crutschow

    Closed loop for two brushless motors

    Then this is classified as homework and should be in that forum. With that, we don't do homework, so you need to show us you approach to solving the problem and we will help.
  13. crutschow

    Simple MUX circuit

    It likely should be a relay designed for low current (dry circuit) switching, usually having gold plated contacts, to avoid problems with high contact resistance due to contact oxide formation.
  14. crutschow

    DAC vs digital potentiometer

    So what resolution/accuracy do you need for that adjustment. That may well determine whether to use a digital pot or a multiplying DAC. What signal frequencies are involved?
  15. crutschow

    Variable DC

    Depending upon the motor current the 3055 will require a heat-sink. That's the advantage of using PWM, as the transistor requires little or no heat-sink.
  16. crutschow

    Small amplifier project power requirements

    The "warm" sound is from the tube rolling off the high frequencies, similar to a low-pass filter.
  17. crutschow

    Help Understanding Simulation Errors

    How did you build those models or where did they come from? Spice requires very particular syntax for all Spice models. But I'm not familiar with KiCad simulations so can't help you beyond that.
  18. crutschow

    Use speakers with AV receiver

    That's a short burst. The amp will likely only cut out from heat build-up for long duration, high volume sound. Also most of the sound energy of that movie blast is likely in the bass region which will be handled by the subwoofer, which should have it's own amp. (Are you planning to use the...
  19. crutschow

    Use speakers with AV receiver

    Not really. The manual says it will do: • 100 Watts/Channel @ 6 ohms (IEC) and it also states: • You can connect speakers with an impedance of between 6 and 16 ohms. If you use speakers with a lower impedance, and use the amplifier at high volume levels for a long period of time, the...
  20. crutschow

    Some input/help on this circuit

    No. Any output load on the op amp will unbalance the current and cause a problem, as it has no path to the AC supply. On way get a plus and minus supply is to ground one terminal of the AC supply, and use two diodes connected in inverse parallel at the output to get two half-wave rectified...
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