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  1. Hero999

    Noise Noise Noise

    What are you trying to monitor?
  2. Hero999

    detectors in soccer

    Short of using a complex image recognition system the only way to distinguish the ball from the goal keeper is to tag the ball in a similar manner to how goods are often tagged to tackle shoplifting. The trouble is I'm not aware of any anti-shoplifting system fast and accurate enough to be used...
  3. Hero999

    50V, 50A H-Bridge IC needed

    That's not always true. It depends on the MOSFET and the IGBT, as I said before, for devices with higher voltage ratings IGBTs are best but for low voltage devices MOSFETs are much better. If you're going to use zeners then you might as well replace R1 and R3 with zener diodes to limit the gate...
  4. Hero999

    audio amplifiers

    Yes.
  5. Hero999

    digital angle measure?

    You could use a micro-controller with an ADC to display the reading on an LCD. It depends on how accurate you want it to be: a pot will have a typical linearity of 1% which is an error of 2.7
  6. Hero999

    lead acid battery charger

    It should work.
  7. Hero999

    thermo electronics

    Heat loss is power which is not converted to electrical energy. Calculate the thermal power in, calculate the electrical power out and work out the efficiency.
  8. Hero999

    audio amplifiers

    A 20W amplifier can be used to power 60W speakers providing they have an equal or higher impedance than the speakers the amplifier is designed to drive. For example a 4Ω 20W amplifier can drive 8Ω 60W speakers but it can't drive 2Ω speakers.
  9. Hero999

    thermo electronics

    What do you mean Watts are J/s?
  10. Hero999

    how can i reduce current of 1A to less than 50mA

    Agreed, it isn't very well drawn but it does seem to be correct. The correct and normal convention is for the positive power supply to be at the top and the negative to be at the bottom. Where possible real symbols should be used rather than the IC outline. The symbol for a comparator is show...
  11. Hero999

    0-30V Stabilized Power Supply

    You're not listening, you need a 30V transformer capable of supplying 4.2A
  12. Hero999

    Contact Resistance Tester

    I think you need to be able to measure resistances lower than 100mΩ, perhaps 10mΩ? You need a constant current source, an amplifier and a volt meter. For example, if you use a 100mA constant current source, the voltage across the unknown resistance will be equal to 0.1V/Ω, adding a amplifier...
  13. Hero999

    how can i reduce current of 1A to less than 50mA

    Why would it be damaged? Use Ohm's law to calculate the current and power dissipation and choose a resistor with a higher power rating.
  14. Hero999

    i need schematic diagram on measuring devices.... pls post...

    No single device can do all of that: you need a different sensor for each of those measurements.
  15. Hero999

    60W Guitar Amplifier

    Yes, that will do: Cat. MT-2114 25+25 Volts 3.2 amps  6.4 amps. Connect the two 25V windings in series to make 50V. Be careful, even the secondary side of the transformer is a high enough voltage to shock you, it shouldn't kill you but it will hurt.
  16. Hero999

    60W Guitar Amplifier

    The capacitors are in μF. Use a transformer with twin 24V windings. It's also possible to use a transformer with a single 24V winding but the rectifier needs to be configured as a voltage doubler and the filter capacitors need to be twice the size.
  17. Hero999

    A cool project website i found

    That depends on the size of the transformers, small mains transformers are very inefficient, typically 50% for a 1VA unit, larger transformers are much more efficient 98%. Superconducting transformers are 99.9% efficient.
  18. Hero999

    A cool project website i found

    It's a matter of opinion I suppose but I'm not very impressed. The colour scheme makes my eyes sore. I thought about going around copying loads of projects for Silicon Tronics but I decided against it, even if it would increase the amount of traffic. In the end I decided to slowly add more...
  19. Hero999

    50V, 50A H-Bridge IC needed

    R1 and R2, and R3 and R4 form potential dividers which limit the gate voltage to the high side MOSFETs to a safe level, whether their values need to be changed for operation at 25V depends on the drain current at the lower gate voltage. The MOSFETs are normal enhancement MOSFETs with built-in...
  20. Hero999

    I need some help - My first electronics project

    Sorry, I can't help you much with microcontrollers because I don't have much software knowledge. Here are some tutorials I'm currently reading. http://www.gooligum.com.au/tutorials.html http://www.winpicprog.co.uk/pic_tutorial.htm
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