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  1. C

    Can we charge a battery using a power supply?

    There are 3 completely different types of Lead Acid Batteries. Which one do you have?
  2. C

    Understanding Inductors

    I have described inductors in a completely different way on my website but I am not allowed to give the link as I get banned from the forum for promoting my website. The most important part to understanding an inductor is the fact that it produces magnetic flux when a current flows and this...
  3. C

    Can the slipring handle the current?

    I have absolutely no idea what you are doing but delivering a signal or power through a sliding contact produces an enormous amount of noise and this is the first thing that will mess up all your results.
  4. C

    electrolytic capacitor polarity help

    Where do you get the reverse polarity nonsense from ??? The electrolytic charges to about 1v in the forward direction and when the circuit turns OFF, the base of the PNP transistor rises about 1v above the supply voltage. The base-emitter junction of a transistor can go up to about 5v in the...
  5. C

    4xLCD torches in series without using 4 lots of 3xAAA's

    "I have a small LED torch that uses 3 AAA cells as well, it's a high intensity white LED, and I'm pretty certain it's just a 1W LED." To start with, you cannot draw more than 100mA from AAA cells. You would be lucky to draw 25mA in a small LED torch and maybe up to 50mA.
  6. C

    Digital volt meter doesn't like a power supply?

    See, how clever you are.
  7. C

    Methods to reduce wall power current?

    "Haha. I was waiting for this kind of response. WT serious F Colin?" If you haven't done a 3 months electrical course and know what putting 4 resistors in series/parallel means, don't make a fool of yourself on this forum. He already said: My latest attempt was with a 25W 0.47 ohm resistor...
  8. C

    Digital volt meter doesn't like a power supply?

    Put 1,000u 25v across the output and see if the voltage can be read.
  9. C

    Amp measuring

    You have to connect the meter around only one wire. That's why it is best to take it to the meter-box where you will find individual wires. That's what electricians do.
  10. C

    Car Alarm Circuit

    The amplifier is just Q5. However Q4 will improve the gain of the amplifier by 100 if all the other components are removed.
  11. C

    Methods to reduce wall power current?

    Use 4 x .47 ohm in series/parallel
  12. C

    Digital volt meter doesn't like a power supply?

    All your "DC stuff" may have its own internal rectifier and regulator.
  13. C

    Wanted: Talema AC1015 current transformer

    Buy a new ELD from eBay for $25.00
  14. C

    Working with an RC timer and a transitor to power a high current device

    See the 120k resistor . . . . . . the transistor effectively reduces this value by 100 (the gain of the transistor). So, the transistor becomes equal to 1.2k. Put a 1k2 in place of the transistor and see how loud the piezo is.
  15. C

    How to make Toy Voice Changer (AA battery) Run on 12 Volt

    Fit a bigger speaker.
  16. C

    Powering a radio with solar cells

    A single solar cell is 0.5v
  17. C

    4xLCD torches in series without using 4 lots of 3xAAA's

    Just connect one to the 5v of the USB and look at it through a camera. Then connect the second third and fourth in parallel.
  18. C

    Single Digit Seven Segment Display Scoreboard HELP!!

    High Bright displays work perfectly with 4026 and 4033.
  19. C

    Single Digit Seven Segment Display Scoreboard HELP!!

    4026 and 4033 are designed to drive 7-segment displays.
  20. C

    Single Digit Seven Segment Display Scoreboard HELP!!

    What is the point of the ULN IC's ??
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