Search results

Search Forums New Posts
  1. Alec_t

    Energy storage - alternatives to batteries

    Twisted rubber bands? Clockwork?
  2. Alec_t

    Uploading pictures to the forum

    In the dialog box, yes. Why not in the sticky text too?
  3. Alec_t

    Uploading pictures to the forum

    Could the sticky also show a list of permissible file types (extensions)?
  4. Alec_t

    Simple JFET Switch Question

    Can you list them?
  5. Alec_t

    Cell phone detector circuit

    It just might do that, if it's very close to the phone and if C1 and C2 are both rubbish capacitors with a high enough equivalent series resistance.
  6. Alec_t

    Heat batteries

    Google 'resettable thermal cutouts'. Do you also have a suitable battery management system to prevent over charging and discharging of the battery? That is important, as lithium batteries can catch fire or explode if not treated properly.
  7. Alec_t

    My inverter is not working and, please help I may not graduate because of this

    That's where it should be connected, but I don't see it in your schematic or board layout.
  8. Alec_t

    My inverter is not working and, please help I may not graduate because of this

    I don't see a connection between the VS input of the IC and the top MOSFET's source. Without that the boost won't work.
  9. Alec_t

    2 Q about antennas.

    Each dish would need to have a diameter of several wavelengths to be really effective. One wavelength at 120MHz ~= 2.5 metres !!
  10. Alec_t

    Grid tie inverter controller?

    If you're planning to feed power back into the grid you would need the approval of your mains power supplier and your inverter would have to be type approved.
  11. Alec_t

    Activating Carbon for conductivity.

    Have you tested the conductivity of artists' charcoal sticks?
  12. Alec_t

    Potentiometers not working? (Stylus organ)

    Looks as though the black and red wires from the speaker aren't connected to anything.
  13. Alec_t

    How to make transistor ON

    Sort of. For an NPN transistor, if the base is taken negative far enough (typically about 5-6V) with respect to the emitter then the base-emitter junction breaks down and current can flow. But the breakdown damages the transistor to some degree.
  14. Alec_t

    Low frequency piezoelectric actuation optimization of waveform

    I would do an experiment to measure the difference.
  15. Alec_t

    Low frequency piezoelectric actuation optimization of waveform

    Welcome to EP! Horses for courses? If the main criterion is pumping at maximum pressure and flow rate I would have thought a square-wave voltage excitation would be the most effective and certainly the simplest. If the main criterion is achieving non-pulsatory flow, then trapezoidal or...
  16. Alec_t

    Designing a soldering iron for limited dexterity

    For how much longer, I wonder? The trend these days, at least in commercial products, is to use surface-mount components rather than through-hole ones. The latter are getting more difficult to source. A tool which simplified the soldering of surface-mount components would be really useful.
  17. Alec_t

    Wahl "Peanut" Electric Razor blown

    No. It's a bridge rectifier to convert the AC mains to DC for the motor.
  18. Alec_t

    Repair to Control Board PCB of Whirlpool Oven

    Members may be struggling to work out what is connected where. You have the benefit of a board in front of you. It would help if you could highlight/annotate/label relevant points in an image. You can upload images to this site to make it easier to follow the thread.
  19. Alec_t

    SCR Motor Controller

    Yes. Since the average current through the motor is reduced the torque will likewise be reduced.
  20. Alec_t

    Help with 555 latch circuit

    If R1 and R2 are both made 100k that will certainly help, but the existing 100k should be reduced to ensure >2/3 of the supply voltage and < 1/3 of the supply voltage is reached when the button is pressed.
Top