Search results

Search Forums New Posts
  1. Alec_t

    LT1528 voltage drops too much

    It would be unwise to try and push 0.7A through breadboard connections. You really do need a pcb/stripboard with soldered connections.
  2. Alec_t

    Creating 5V DC

    Four NiMh cells in series? The pad voltage isn't critical.
  3. Alec_t

    LT1528 voltage drops too much

    Welcome to EP. How much current do you need to draw from the regulator? Was the 200mA just for test purposes? Edit: Perhaps a high-resistance contact in the breadboard is dropping the voltage?
  4. Alec_t

    Current control and defence

    Diverting current through the transistor will place a heavier load on the AC supply. Unless the supply itself has some way of limiting current (e.g. significant resistance) it may self-destruct.
  5. Alec_t

    Step Down DC Buck Capacitor Blow up

    As I replied on another forum, it may be that the converter requires some minimum output current to regulate properly. A meter alone draws little current.
  6. Alec_t

    Cons of using large transistors?

    That's where the frequency response and large gate/junction capacitance that Bob mentioned become a problem, regardless of the heatsink size.
  7. Alec_t

    Cons of using large transistors?

    Welcome to EP. For many circuits, particularly those operating at DC or low frequency AC, there would be no drawback.
  8. Alec_t

    Term Project - Air Conditioner (of Some Sort.) - any aid is welcome.

    Welcome to EP. You could start by researching: "comparator schematic", "comparator hysteresis" and "PWM duty cycle".
  9. Alec_t

    A easier way to design a multilevel inverter switch

    Welcome to EP. Are you going to share this desigh then? Schematic?
  10. Alec_t

    Super Hot Capacitors...!

    Sounds like the hot caps have too high an ESR. Replace them with good quality low ESR 105C types.
  11. Alec_t

    Standard Incandescent Bulb Salvaging

    You may find that the lamp base solder has a high melting point, so less easy to solder with on circuit boards. Plus, you'd have to apply flux externally instead of having it in convenient wire cores.
  12. Alec_t

    transistor for open-drain / open-collector 25kHz PWM

    Almost any common or garden NPN bjt would do the job, e.g. 2N3904.
  13. Alec_t

    Overkill LEDs and PWMing with electric switch

    A mechanical relay will be too slow. MOSFETS would be the most practical switching devices. Different LED colours have different current maxima. Which colour are your LEDs? How many modules do you plan to combine? What power supplies do you have?
  14. Alec_t

    Cant get a voltage reading off an working AC/AC Adaptor with a multi meter ?

    Sounds like the unit is faulty.
  15. Alec_t

    need help with usb powered ultrasonic humidifier

    I thought all computer/tablet cameras could do stills?
  16. Alec_t

    Advice on antifreeze heater?

    ..... but, since the light is bouncing around inside a closed box, virtually all of the light energy will also be converted to useful heat energy.
  17. Alec_t

    need help with usb powered ultrasonic humidifier

    .... which unfortunately still aren't focussed sharply enough for a diagnosis. Treat yourself to a decent camera for Christmas :) .We need to be able to see all circuit tracks and component lettering clearly to have any chance of suggesting where the fault may lie.
  18. Alec_t

    ECG front end simulation

    Since this is simulation rather than real life you can use any comparable amp model.
  19. Alec_t

    why connect a jfet gate to source?

    What was the Vds when you measured it? The ON datasheet quotes the current for Vds=15V and a pulse time <= 630mS.
  20. Alec_t

    precision voltage regulator adjustable

    No, I mean two resistors in series, with output from the junction. Your PWM will be putting out 5V (or 3.3V, depending on your micro's supply) pulses, so you will need to reduce that in order to get mV levels without resorting to absurdly small duty cycles. The low-pass filter could go before or...
Top