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  1. S

    Fluorescent lamps in series using electronic control gear?

    LEDs flicker at a rate detected by video camera and high frequency control gear don't plus the LED tubes don't light up 360 degrees and my plan is all about aesthetics.
  2. S

    Fluorescent lamps in series using electronic control gear?

    Thanks. I suppose making my own dimmable high frequency control gear for 16 6 W fluorescent bulbs isn't feasible for someone with no background in electronic engineering? They don't seem to make dimmable control gear for wattages less than 14 and 14 W tubes are too long for my application.
  3. S

    Fluorescent lamps in series using electronic control gear?

    I would like to make a lamp using many small T5 fluorescent tubes (maybe 12 or 16). I would like to use a dimmable high frequency electronic control gear (not a starter and ballast). You don't seem to be able to get dimmable control gear for 6 W tubes. I was wondering if I could put four 6 W...
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    Which leg is which for PNP power MOSFET IRF5305PbF?

    Thanks very much. It was for a project to light a green LED whenever my ESD grounding point is connected to ground but it turns out that neither a transistor nor MOSFET is suitable (a MOSFET even less so because it lights up when I touch the probe without a need for two connections to ground)...
  5. S

    Which leg is which for PNP power MOSFET IRF5305PbF?

    I have PNP power MOSFETs called IRF5305PbF. The datasheet doesn't say which leg is which. Should it be obvious?
  6. S

    Reverse character LCD polarisation?

    You seem to suggest that an LCD cannot be inverted by rotating the polariser but if that's the case then what is the basis of this LCD watch modification?
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    Reverse character LCD polarisation?

    If I buy a cheap character LCD that displays black characters with a yellow/green background, should it be possible to change it to yellow/green characters with a black background by removing the polariser and replacing it with another oriented 90 degrees to the original? Would the old polariser...
  8. S

    Making a flashing mains indicator LED

    I previously added a mains indicator LED to a hot glue gun by connecting an LED and resistor directly to the mains connection with a diode across the LED to allow current to pass in the opposite direction when the direction changes. For some devices I'd prefer the LED to flash because I think it...
  9. S

    Cheap N-type MOSFET for PWM driving many LEDs with 3.3 V logic?

    I think the answer is RFP30N06LE or FQP30N06L.
  10. S

    Modifying 4.5 V (alkaline) lamp to run brighter with 3.6 V (NiMH)

    Fresh alkaline batteries can have a voltage of 1.65. I'm not concerned. The voltage from the booster will not go above 4.5 V unless more than 4.5 V are supplied which is not going to happen.
  11. S

    Modifying 4.5 V (alkaline) lamp to run brighter with 3.6 V (NiMH)

    4.5 V is the voltage I want to run it at. I never said I want to run it higher than 4.5 V. I tried a cheap variable voltage boost module set to 4.45 V and it seems to work pretty well. I was originally worried about accidentally overdischarging the cells but the lamp begins to flicker when the...
  12. S

    Cheap N-type MOSFET for PWM driving many LEDs with 3.3 V logic?

    I'd like to copy this project to automate some RGB LED strips. It calls for some N-type MOSFETs to turn on and off LEDs in a pulse-width-modulated way. What would be some suitable MOSFETs that can permit at least 1 A? I know I could find something myself but I wouldn't know whether it was some...
  13. S

    Small low-power light sensor

    I can test the LDR resistance in-circuit and it seems to be working fine (20 K in light, 1 M in dark) so I don't think it's the LDR at fault.
  14. S

    Small low-power light sensor

    I ended up implementing this in a slightly different arrangement than I first intended. It worked as expected for a day or two, turning on only in low light, but now when I turn on the circuit, the light comes on immediately and stays on regardless of the intensity of ambient light. If I try to...
  15. S

    Modifying 4.5 V (alkaline) lamp to run brighter with 3.6 V (NiMH)

    The battery compartment is designed for three. A fourth cell would be an awkward thing to add to the outside of the case and I think would leave the cells vulnerable to reversing polarity during discharge, plus the voltage might be too high when freshly charged? It would also no longer be...
  16. S

    Modifying 4.5 V (alkaline) lamp to run brighter with 3.6 V (NiMH)

    It doesn't use a bulb but three SMD LEDs which are connected in parallel. This is the circuit that feeds the LEDs (there are no other components on the board with the LEDs). I figured the simplest thing to do would be to add a circuit between the battery and the original circuit which would...
  17. S

    Modifying 4.5 V (alkaline) lamp to run brighter with 3.6 V (NiMH)

    I have a lamp which takes three D-size batteries. It seems to have been designed to function best with alkaline batteries and is relatively dim (in fact the bright and dim settings both appear the same) using 1.2 V NiMH batteries. I was wondering what circuit I might use to increase the...
  18. S

    555 timer for a fan

    Adding a momentary switch across the 10 nF capacitor at pin 5 cancels the timer.
  19. S

    555 timer for a fan

    Can it not be done with a momentary switch? I'd like the circuit to stay on so I can use a single button press to start the fan again.
  20. S

    555 timer for a fan

    I'm using a cheap module which takes the voltage of a lithium cell and increases it to 5.3 V (it's meant to be 5 V but 5.3 V is what it actually provides) since I have a few of them already. I'm not really happy that the 2N2222 Vce is 2.7 V even after reducing the value of the base resistor to...
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