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  1. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Which two resistors are "wayward"?
  2. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Let it sit for one hour with no load. Feel everything, nothing should be hot. Current times voltage equals heat. Your current meter measures the load's current, not the entire project's current. The parts in the circuit draw a very low current when there is no load and nothing is wrong.
  3. Audioguru

    Replace 9Volt Battery with Solar Panel

    Using a solar panel then a battery charger circuit is missing and a diode is missing to prevent the battery from discharging into a dark solar panel. Energizer and other Ni-MH battery maunfacturers say the life of a Ni-MH battery is reduced if its trickle charge current is more than 1/40th its...
  4. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    When pin 3 of U3 has a higher voltage than the project output voltage then U3 is not reducing the current through D9 by reducing the output voltage. Measure the output voltage of U3 to see if it is wrongly reducing the input of U2. What resistance is the project's load?
  5. Audioguru

    TDA2030 amplification is very less

    You correctly copied the single supply circuit in the datasheet except the supply voltage is too low. Its minimum supply is plus and minus 6V that is 12V but you have one 9V battery that drops below 6V. Try the TDA2030A with two 9V batteries in series but power the 555 with only one of the 9V...
  6. Audioguru

    Amplifier

    A transformer was used in a class AB amplifier circuit 63 years ago. Why are you using a transformer today? Here is a modern circuit with no transformer:
  7. Audioguru

    Replace 9Volt Battery with Solar Panel

    They renovated a nearby shopping center and put a large glass ball on top. When it gets windy the curved glass panels on it shatter. They replaced the broken glass and maybe all of it with plastic pieces. It takes them 1 week to put up a scaffold so that the 9V batteries in the smoke detectors...
  8. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    The duration of the large capacitor charging is too short for a DMM or analog MM to accurately show its amount of current. An oscilloscope is needed to show it. I wonder if the core of the transformer is saturating by the high pulse of current that makes the amount of current even higher.
  9. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    I think your DMM cannot measure the short duration peak current of the big capacitor charging and your fuse is a fast blow not a slow blow.
  10. Audioguru

    Darlington transistor suggestion ?

    Graphs on a datasheet are for "typical" devices that you cannot buy, you get what is available. Devices with passing but minimum spec's are much worse and probably will not work if the circuit is designed with the graph numbers. When I design a circuit I look at all minimum and maximum specs so...
  11. Audioguru

    ebike with speaker amp as a watt amperage is it possible

    Almost every ebike I see on the road is creeping along with a dead battery or a rider who is very overweight. Since you want lot of power and high speed on your ebike then you need a jet turbine engine on your back. Then your ebike can pull a trailer full of fuel instead of a trailer full of...
  12. Audioguru

    ebike with speaker amp as a watt amperage is it possible

    Your original 250W motor used a 36V battery. Is the new 350W motor also designed for a 36V battery? Isn't the razor control box designed for a 250W/36V motor and 36V battery? Then of course the control box is fried. When the battery voltage is doubled then the current is also doubled. Then the...
  13. Audioguru

    Darlington transistor suggestion ?

    Instructors and books are often wrong. I find descriptions of hFE and hfe in datasheets. When will everybody understand that the threshold G-S voltage of a Mosfet is when it BARELY turns on with a very low current that is so low that it is almost turned off??
  14. Audioguru

    ebike with speaker amp as a watt amperage is it possible

    If you use a more powerful motor then each battery discharge will be shorter in time if you use the additional power or the battery might catch on fire. You will probably need a larger more powerful battery. A more powerful motor will also need a more powerful motor driver circuit and thicker wires.
  15. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    I looked in Google Images for Glass Slow Blow Fuse and it showed photos of fuses with a thin wire, a thick wire, a coil of wire and a thin wire with two or three dots on it like yours. Some are correct and some are wrong.
  16. Audioguru

    Darlington transistor suggestion ?

    No. hfe is AC current gain, hFE is DC current gain when the transistor is an amplifier, not a switch and is NOT saturating. Most transistors saturate as a switch fairly well when the base current is 1/10th the collector current even if the hfe and hFE are very high.
  17. Audioguru

    ebike with speaker amp as a watt amperage is it possible

    I translated the horrible "Engrish" to be: He thinks that an audio amplifier will amplify the power of a battery. He also does not know that the ebike motor uses 36VDC but the output of an audio amplifier is not DC, instead it is AC and 3000W into a 4 ohm speaker is a voltage of 109.5AC that...
  18. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Your 0.75A/250V slow blow fuse is fine if the project does not get hot when powered with no load.
  19. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Did the series lamp just flash for a moment when the project was switched on or did the lamp light continuously? 238V at 0.75A is a power that is way too high of 238V x 0.75A= 178.5VA. The project draws only 118VA when it has its maximum output current of 3A. A fast blow fuse might blow as the...
  20. Audioguru

    BMS for Lithium Iron phosphate battery bank LiFePo4

    If something looks too cheap to be true then guess what?
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