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  1. KrisBlueNZ

    Voltage converter 120V to 220V

    No, the transformer doesn't change the frequency! The amplifier will work with either frequency. But re-read Steve's advice.
  2. KrisBlueNZ

    Project - Conveyor system using 555's

    That's better. There are still a few errors. 1. RT1 shouldn't be there, obviously. It will limit the motor current to about 1 mA! 2. If the load is inductive, when the transistor turns off, the peak current through D1 could be as high as the operating load current. If that is 5A, you should...
  3. KrisBlueNZ

    Voltage converter 120V to 220V

    I don't know. Personally I wouldn't buy anything from Goldsource.
  4. KrisBlueNZ

    Remote Control Circuit with CD4017 - counter decoder

    It's OK that you don't measure any continuity between Vcc and OUT. The "resistor" inside the module is probably implemented as a current source made from semiconductor components, which are easy to manufacture as part of a silicon chip, instead of a real resistor. So it won't have any continuity...
  5. KrisBlueNZ

    switch that turns off upon trigger

    Do you mean that you WANT the "other" switch to close automatically when you switch the selector switch to position A or B? Normally, a switch can only change position when operated by a person. So you want a switch that can also be operated electrically? I don't know of anything ready-made...
  6. KrisBlueNZ

    Voltage converter 120V to 220V

    That transformer you linked to, Goldsource TC-500W, has a pretty low price for a 500W transformer. I suspect it may not be very good quality. An identical unit is shown at http://videooverseas.com/500-watts-tc-500w-universal-socket-step-up-step-down-voltage-transformer.html as "Simran" brand...
  7. KrisBlueNZ

    Remote Control Circuit with CD4017 - counter decoder

    Yes, in this case, Vs and Vcc mean the same thing. "Current is not able to flow from Vcc to OUT"? I'm not sure what you mean. Do you mean it measures open circuit between those pins when you measure its resistance? That isn't necessarily a problem. You can test it in the circuit. Measure the...
  8. KrisBlueNZ

    Help please

    Sorry for the delay! You can do a basic check by measuring the power supply voltage to the LM324. That's the 14-pin IC near the top of the board. Here's a diagram of it: This shows it viewed from above. Measure the DC voltage between pin 4 (V+) and pin 11 (GND) on the IC. I assume you have...
  9. KrisBlueNZ

    graph of time constant rc network

    Your first misunderstanding is in the definition of "time constant". The time constant of an RC circuit is defined like this: t = R C In other words, t, the time constant of an RC circuit is equal to the resistance (in ohms) multiplied by the capacitance (in farads). Its unit is seconds...
  10. KrisBlueNZ

    T4010A1 ultrasound Transducers

    Hi there and welcome to Electronics Point :-) It is "polarised" in the same way that a loudspeaker is "polarised" - when current flows one way through it, the moving part moves forwards, towards the open port, so it pushes air outwards; when current flows the other way through it, the moving...
  11. KrisBlueNZ

    Voltage converter 120V to 220V

    Yes, I agree with Steve and duke37. It doesn't look like there's any way to support 220 VAC. I did say "don't get your hopes up". I'm surprised to see both a large-ish power transformer and a large-ish switching supply. But neither of them looks like it can be changed to support 220 VAC, and...
  12. KrisBlueNZ

    Remote Control Circuit with CD4017 - counter decoder

    No, that's not the information I need. I don't think the data sheet has that information. It will probably be fine.
  13. KrisBlueNZ

    Voltage converter 120V to 220V

    That's a pretty impressive amp! Unfortunately I can't find any technical information on the power supply it uses. Can you open it up and take a couple of photos of what's inside? Especially anything that's connected to the mains input socket.
  14. KrisBlueNZ

    Voltage converter 120V to 220V

    What's the model number of your amplifier? It may be possible to make changes to the power supply to allow it to operate from 220 VAC. Don't get your hopes up, but if you tell us the model number, we may be able to find out enough to say whether that's possible. We may need to ask you for some...
  15. KrisBlueNZ

    Remote Control Circuit with CD4017 - counter decoder

    Yes. In the block diagram, there is a resistor connected between the OUT pin and VCC. Can you find out anything about this resistor? Either its resistance, or the output current when the output is high.
  16. KrisBlueNZ

    Remote Control Circuit with CD4017 - counter decoder

    The VS1838B will probably work. I found a data sheet but it's in Chinese and I can't read it, so I can't be 100% sure. If it's not too expensive, it's worth trying.
  17. KrisBlueNZ

    Project - Conveyor system using 555's

    Thanks for trying to help, but... 1. The OP is using his 555s as monostables, not astable oscillators; your circuit shows an astable oscillator; 2. Your circuit cannot provide 1A because the 2N2222 is only rated for 800 mA collector current (600 mA from some manufacturers). Even if it was rated...
  18. KrisBlueNZ

    Remote Control Circuit with CD4017 - counter decoder

    Sorry, I'm getting this thread confused with a different one! Right, it should be a 2-pin resonator. The one you have will probably work.
  19. KrisBlueNZ

    Remote Control Circuit with CD4017 - counter decoder

    Yes, the TSOP4038 looks suitable. Does that CRV455E have three pins? If so, it's very likely that it will work. OK, I've added your location to your profile. It's often useful for us to know where you are. So RS Components have the CD4069UBE and CD4024BE, but only in quantities of 25 and 10...
  20. KrisBlueNZ

    Help! What is this component and why is it getting so hot!

    I think you're right, superjon. It's probably a write-off. I can't find a suitable replacement on Digikey or Mouser, and they're the biggest electronic component etailers around. If you're really keen though, you could replace the regulator with an adjustable LDO regulator with two feedback...
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