Search results

  1. W

    Does MAX232 support UART?

    The MAX232 is nothing more than a level shifter taking in 0-5V and outputting +/-10V
  2. W

    DC/DC Converter (the proper diode)

    Your diode needs to be a Schottky diode for its speed. Any normal diode (1N4001 etc)will be too slow, the energy in the inductor will not dissipate quick enough into the output capacitor and you will get a spike where the diode and inductor meet. Not good for noise and long life of the diode
  3. W

    Polarity Switch

    I am surprised no one has replied to this. You need an H Bridge circuit: http://en.wikipedia.org/wiki/H-bridge and apply your load across the centre. You can then set the polarity of the voltage to your load by the switching of the transistors
  4. W

    Power electronic converters

    back to the asylum on Monday....
  5. W

    0-30 VDC STABILIZED POWER SUPPLY HELP

    Connect the positive terminal of your ammeter to the output of your power supply and the negative end to your load. This will read the current going into the load
  6. W

    How to use a BJT as a switch..

    get two pnp transistors. connect their emitters together and connect these to the power input. Drive the bases low via a 10k resistor. Take the outputs from each collector. Once again, your posts do not make a lot of sense. If you used proper English, you might get more help. At a guess, I...
  7. W

    What is the value of component R4 in UltrasonicRadar

    If you posted more sensical questions, you will get more replies. I cannot understand what you are asking... It sounds like it is 3.9k. 3.9k and 3,9k sound like the same thing
  8. W

    Capacitor help for a newbie

    ... and you need to place the capacitors as close to the supply pins as possible...
  9. W

    power supply ircuit Help

    It depends on what type of battery you have. To charge batteries you need a constant current source, but the method of charge termination varies from chemistry to chemistry. Lead acid batteries charge with a constant current then need a float voltage top off. NiCads and NiMH need a change in...
  10. W

    [b]Questions regarding Switched-Mode Power Supply[/b]

    I appreciate inductors and capacitors have resistance and will dissipate heat. I was talking theoretically to make the point easier to understand. Considering the wider picture, you need to look at switching times (passing through the linear region of the FET will dissipate heat). You will also...
  11. W

    audio circuit to say "Wikommen" once when car ignition turned on

    Have a look at ISD.com and their Chipcorder range. You can just record your own speech into it and play it back. You dont have to worry about triggering an MP3 player etc. Not sure what you amp looks like and whether you can feed a line in signal into it, so connecting this circuit up could be...
  12. W

    [b]Questions regarding Switched-Mode Power Supply[/b]

    switched mode power supplies rely on 2 priciples: a switch does not dissipate any heat: heat = volts x current in a switch the current is zero when switch is open or voltage is zero when switch is closed. therefore heat dissipation is always zero (theoretically). Also inductors and...
Top