Search results

  1. Hero999

    Solenoid driver circuit

    I've never heard of Livewire so I Googled it. Maplin sell it for an overinflated price. http://www.maplin.co.uk/livewire-circuit-simulator-33100 When you mean it blows out, do you mean Livewire thinks the absolute maximum rating of a component has been exceeded so shows it exploding?
  2. Hero999

    timer to trigger latch

    The 555 timer is the obvious one but it depends on what you're doing.
  3. Hero999

    Where to find solder tips

    I doubt it will last a year but good luck with it. You really need a temperature controlled iron. You can substitute this with a cheap plug-in lamp dimmer but the iron's wattage may be too low.
  4. Hero999

    Beats by Dr. Dre Headphones

    For cheap wireless headphones buy an FM transmitter an a tiny FM radio.
  5. Hero999

    950 watts at 12V using 80 AA batteries

    It's possible but is a silly idea. You need to be very careful when connecting batteries in parallel because they need to be balanced to ensure each cell has the same level of charge. You should use a large lead acid battery which will work out cheaper. If it really needs to be compact use...
  6. Hero999

    how to send ECG through gsm

    Sounds like a silly idea to me. Email is a better method.
  7. Hero999

    IR Switch for LED

    You're right about the comonent values and capacitor suffix. Tolerance isn't important for capacitors either. You've got the diode right. Just pick an 74HC14 in a through hole DIL package. You'll also want some strip board to assemble it on.
  8. Hero999

    inverter

    The IRF750 springs to mind. http://www.ic72.com/pdf_file/i/49649.pdf The hardest part of building a switched mode inverter will be controlling the MOSFETs across the isolation barrier. You can use a pulse transformer for this but it needs to be able to work down to 50Hz.
  9. Hero999

    inverter

    It looks like a good article. I like the way you figured out you need to use a modified sinewave and that the peak voltage needs to be the same as the mains. If you use a ready made transformer, you can use 9V-0-9V for 12V input and 18V-0-18V for 24V input. The only thing I have to pick you up...
  10. Hero999

    IR Switch for LED

    You've got the value of R7 wrong there. In the previous schematic you posted, you got the values of R1 and R5 wrong. You need to be more careful with your decimal suffixes. Resistors are always specified in Ohms. If there's no suffix, or the letter R is used, it means *101 so a resistor with...
  11. Hero999

    Roms for N64oid

    You won't find them, because they're illegal all the good ROM sites have been shut down. The only place to get them now is bittorrent.
  12. Hero999

    IR Switch for LED

    My criticism was aimed more at not showing the gates inside the box, than drawing it that way to help you to lay it out. I've corrected the resistor values. The wattage can be calculated by looking at the voltage across the resistor and applying Ohm's law. P = V2/R So for R3 P = (4.5-1.2)2/82...
  13. Hero999

    current spike

    To allow one 555 to control another you're better off just connecting the output to pin 4, rather than switching the eintire power supply. Don't worry about the power spike, it's unavoidable  and is caused by the fact the transistor can't turn on/off instantaneously. It's not a problem because...
  14. Hero999

    ILL PAY$$$--NEED HELP TO DRIVE 35-40 SMD RGB LED

    Reading through what you've posted again, you can connect the LEDs in parallel but each one needs its own series resistor. What's the power supply voltage? Note that the LED forward current specified is normally a maximum value, you should limit the current to less than that. The formula for...
  15. Hero999

    IR Switch for LED

    I've had a look at it. You'll notice that the pin numbers for op-amps are not normally shown on schematics. This is because you can use any gates in the package and what connection goes where will depend on how you lay out the PCB, i.e. whether you're using SMT parts or through hole,strip board...
  16. Hero999

    Good job!

    You're very lucky. We do get quite a lot of spam. Fortunately I or another moderator must've deleted it before you saw it.
  17. Hero999

    ILL PAY$$$--NEED HELP TO DRIVE 35-40 SMD RGB LED

    The specification doesn't make any sense, Amps is the unit for measuring current, not capacitance. Does it boost the voltage? The maximum LED voltage is specified at 35V but the maximum input is just 30V. LEDs should be connected in series not parallel. Does the controller limit the current...
  18. Hero999

    IR Switch for LED

    That's exactly what my circuit does. Except a 20% duty cycle is still too high for decent battery life which is why I chose a duty cycle of 1% and to lower the current to 40mA, which should still be enough to activate the emitter.
  19. Hero999

    IR Switch for LED

    Don't give up too soon it's not as complicated as it seems. The circuit is actually very simple. If you can build the circuit attached, you should be able to build the other circuit fairly easily. It's also pretty easy to explain. A Schmitt trigger is a logic gate with two trigger levels, one...
  20. Hero999

    Spice software recommendations?

    I use LTSpice too, it's a good program.
Top