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audioguru last won the day on January 11

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About audioguru

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  1. We will help you if you build or design a circuit that does not work properly. But it sounds like you want somebody to design a circuit for you. Somebody might do it.
  2. We talked about fixing the cheap Chinese Banggood kit on another website and I do not want to talk about it again.
  3. I think the kit from Banggood and copies of it are selling at a clearance price today because it has been replaced with a better kit maybe with its errors corrected. Of course the new kit costs much more and comes with voltage and current displays.
  4. SUBJ1

    If I write your essay so that you cheat then do I graduate, not you?
  5. The original circuit has many overloaded parts and cannot produce 30VDC at 3A. It is also missing the calibration trimpots that are used in the improved version that can be set to exact maximums of 30.0V and 3.0A.
  6. None of your voltages match. The solar panel produces only 0.5V. The battery produces only 3.7V and is charged from about 5V or 6V. The pump needs 6V. A battery charger does not dump power when the battery is fully charged. It simply turns off the charging.
  7. Nope, your math is wrong. 104 is 10 followed by 4 zeros making 100000pf which is 100nF which is 0.1uF. 222 is 22 followed by 2 zeros which is 2200pf which is 2.2nF which is 0.0022uF. The highest value for a ceramic disc capacitor I have seen is 1uF so use an electrolytic type for 50uF. My multimeter measures capacitance. It also measures frequency, AC and DC volts, current, resistance, continuity and forward voltage of a diode. The AC is measured with True RMS and it automatically switches its ranges when I want it to do it.
  8. ebay means "manufacturer's rejects" and "sweepings off the floor". Don't buy anything from ebay, instead buy from a reputable and reliable Western electronics parts distributor. Haven't you see a datasheet of an old 2N2222 transistor? Like all transistors its hFE is a range of 1 to 3 times and the actual hFE also varies with the collector current. With a collector current of 1mA the minimum hFE is 50 with no guaranteed maximum hFE. With a collector current of 150mA the hFE is guaranteed to be from 100 to 300. hFE is DC current gain that is listed and shown on a graph on a datasheet. hfe is AC current gain that is usually a little less than hFE at low frequencies and is usually not shown on a datasheet.
  9. I can buy a transformer with any voltage that I want. A 28VAC one or a 30VAC one will work in this modified circuit and the circuit will have a maximum regulated output of 30VDC at 3A. If you use a transformer that is 24VAC then the maximum regulated output from this modified circuit will be about 25VDC at 2.5A, and if the voltage and current controls are at maximum then the output will produce lots of unregulated ripple.
  10. I answered on the other website that your suggestion of using a tiny A23 12V battery will light 4 LEDs for only a few minutes and you might even see the LEDs dimming as the tiny battery runs down. Use eight AAA or AA alkaline cells in series instead. Buy Name Brand batteries locally because I think Amazon sells cheap Chinese batteries that have been leaking on a boat for ages.
  11. The datasheet shows how the output voltage is marked. It could be from 2V to 7V in 0.1V increments. I think yours is 2.3V.
  12. 31W a lot of power in the small area so the LED will get extremely hot. How will you cool it? A number of lower power LEDs will be easier to cool. An LED sets its own voltage that you cannot adjust. Its current sets its brightness.
  13. fm

    The circuit is too simple to be an FM radio.
  14. Why are you using the TIP122 darlington to short the 3V battery? The collector and emitter currents will be whatever the shorted battery current will be which might be 8A if the cells are new or be a few mA if they are old. The current gain of a TIP122 is a range from 1000 (the minimum) for some of them to maybe 10,000 or more for others. The Arduino output voltage at 3mA will be less than 5V, maybe 4V so the base current of the TIP122 might be 2mA. Your current meter has a voltage drop so it measures currents low. Maybe the Arduino pulses the Currents and your meter shows the lower average currents. The high current is not going into the Arduino, instead it is going from the battery into the TIP122.
  15. How do you know which ebay Chinese part is a fake and which one is real and good that will work?