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  1. Alec_t

    Bee venom collecting device

    Here you go. Hope it works for you :-
  2. Alec_t

    Nordic semiconductor

    Welcome to EP! I'm not a software guy, but I assume you'd need a compiler to convert the program to machine code and then use a programmer device to load the code serially via pins 25 and 26 (per the datasheet).
  3. Alec_t

    Some Help With Volt Scale Reversal Needed For An Idiot.

    The LM3914 comparators do act like a switch. No turn on/off times are specified in the datasheet, but they would be negligibly small. But why are they a concern? There would be no significant heating of the transistors. There is, however, a deliberate slight overlap between the comparator...
  4. Alec_t

    Wall heater thermostat

    Why would you want to set the stat above 24C?
  5. Alec_t

    Some Help With Volt Scale Reversal Needed For An Idiot.

    I wouldn't dream of using SSRs. Far too expensive and bulky. 2N3906 (or almost any other low current PNP transistor) will be fine, since the maximum gauge current is only ~20mA.
  6. Alec_t

    I Want To Fix My Trimmer

    A battery of that size will typically have a capacity of ~500mAh to 1000mAh. If we assume 500mAh then a safe standard charging current would be, say, 40-50mA. It is likely, therefore, that the charger is rated for that sort of current. Your trimmer motor, however, will almost certainly draw a...
  7. Alec_t

    LED's that plug into 3.5mm???

    Strobe light?
  8. Alec_t

    Some Help With Volt Scale Reversal Needed For An Idiot.

    No. That should do the trick, but do your calculated resistor values take into account the internal components of the meter? By my reckoning the meter probably includes a 5V regulator and at least one series resistor in order to get the set of voltages given in the table in post #5.
  9. Alec_t

    Some Help With Volt Scale Reversal Needed For An Idiot.

    To get the voltage range you want (~0.5V - ~2.5V say) :- Remove RV1, Drive pin 5 directly with the pressure gauge output, Replace RV2 with ~800Ω (1k trimmer) and ~330Ω (500Ω trimmer) in series to ground, Connect pin 4 (Rlo) to the junction of those two resistors (trimmers). However, the circuit...
  10. Alec_t

    I Want To Fix My Trimmer

    The web-site doesn't have the info. In post #8 I asked you for the battery capacity. What does the label on the battery say?
  11. Alec_t

    I Want To Fix My Trimmer

    It's not just a matter of reducing the voltage. Do you know how much current the trimmer motor draws (the mAh rating of the battery, together with the number of hours trimming per battery charge you get, would give us a clue)? What is the mA rating of the charger?
  12. Alec_t

    I Want To Fix My Trimmer

    What is the battery capacity (mAh) rating?
  13. Alec_t

    I Want To Fix My Trimmer

    What are you trying to do? Eliminate the battery and power the trimmer directly from the charger? Or just use the charger to charge the battery?
  14. Alec_t

    Is This A Damaged Connector?

    Welcome to EP! The image link is broken. Post the image to this site using the 'Upload a file' button.
  15. Alec_t

    Led On Indicator

    Anything sold as a "12V LED" will already have a series resistor built in. For a normal LED (~2V), choose a high efficiency type to avoid draining the battery. If, say, the LED is bright enough with only 2mA current, then the series resistor would be (12V-2V)/2mA = 5kΩ.
  16. Alec_t

    Simcard Slot Issue ,not Detecting

    As davenn says. If a power pin was shorted directly to a component instead of via a current-limiting resistor, that component (and a train of others) may now be dead.
  17. Alec_t

    I Want To Fix My Trimmer

    What battery type? NiMH, lithium? ... ? (the type is probably indicated in small print somewhere on the trimmer body)
  18. Alec_t

    Wire color

    AC mains wires are colour-coded too, but the code varies from one country to another.
  19. Alec_t

    Questions conservation electronic

    Yes, if you keep the electronics in a vacuum or in a closed environment which has some other (e.g. mechanical) de-humidifer. Perhaps in a freezer?
  20. Alec_t

    Output 12-30V with 20mA Electrical Source

    Ohm's Law dictates that 12V will drive exactly 20mA through a 600Ω load; 30V will drive exactly 20mA through a 1.5kΩ load.
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