Search results

Search Forums New Posts
  1. Audioguru

    Hi guys/girls. Car project

    A switch will stay turned on until you turn it off. But a button is turned on only as long as you keep pressing it. Which do you have?
  2. Audioguru

    Wiring together LED lighting for a display

    I agree that there is probably a series resistor inside the battery case. Their 20 LEDs string that is powered with three AA cells has an visible resistor.
  3. Audioguru

    Project Help-8 Channel Piezo Signal Booster/Mixer

    The schematic and parts layout drawing of your Chinese amplifier do not match. Does it have and where are Ri, Rf, Cin, and a 100k resistor and switch to SD pin 1? It probably will not work if the Mode pin 3 is not high or low, if pin 1 is not grounded and if Rf is missing. I also downloaded its...
  4. Audioguru

    I have a question about power supply requirements

    I think many laptops use a 19V power supply. A car radio uses a 13.8V power supply.
  5. Audioguru

    Wiring together LED lighting for a display

    The LEDs survive when powered by the weak little battery cells because the battery cells have series resistance in them that limits the current. A CR2032 battery cell is rated at a very low current of only 0.19mA. A 6VDC power supply will quickly destroy the LEDs. You must add a separate...
  6. Audioguru

    Battery - Charge or be Charged?

    You must learn about the dangers of charging and discharging a Lithium-Ion battery to avoid an explosion and/or very hot fire. Usually a charger IC is used that is programmed for the spec's of your battery. The IC has many safety features in it. The phone already has a charger circuit in it. It...
  7. Audioguru

    I have a question about power supply requirements

    The biggest most powerful wall-wart I have produces 12V/1A with a fairly large low frequency transformer. I have tiny lightweight 5V/2A switched mode high frequency power supplies but their voltage is too low for my amplifiers so I do not know if they produce noises. Your amp needs 12V at...
  8. Audioguru

    I have a question about power supply requirements

    When I design an amplifier then I make it have its own filter so that it works fine with almost any power supply. But I don't buy cheap power supplies from ebay.
  9. Audioguru

    Optical Pickup

    Some singers (Drake and many more) read the lyrics of a song and the electronics of "Autotune" can make anybody sing accurate musical notes. Is that what this optical guitar needs to do?
  10. Audioguru

    I have a question about power supply requirements

    I think a filter costs money so if the wall wart is a cheap one then it has a poor filter.
  11. Audioguru

    I have a question about power supply requirements

    If the 12V amp has a 3A fuse then it can be powered from a 12V at 3A or more power supply. If the power supply is a cheap wall wart then the amp will probably produce hum.
  12. Audioguru

    Total Newbie Question: Using a relay as a switch?

    A red LED uses only 1.8V. The 12V relay needs at least 9V that your doorbell does not have. The input to a transistor can behave exactly like the LED in the doorbell circuit but the bright lights it drives need an extra power source.
  13. Audioguru

    Project Help-8 Channel Piezo Signal Booster/Mixer

    There are many audio mixer circuits in Google with a single opamp that allow each input to have its own volume control. Please post the schematic of your mixer circuit that did not work.
  14. Audioguru

    Sometimes a monster

    I know nothing about your cheap tools but I found the horrible old project:
  15. Audioguru

    Current hogging prevention

    An RC receiver uses a battery, not a power supply. Nobody makes a 5V battery, it is probably two Li-PO cells in series making 8.4V when fully charged and delivering a massive current, much more than a puny 3A. My very small and lightweight two-cell Li-PO batteries are rated for a continuous...
  16. Audioguru

    Rolling Up a Flatscreen TV

    Will the TV work with the Brazil TV system that might be different to the American TV system?
  17. Audioguru

    can IR sensor be changed?

    I do not have interference between my remote controls. I do not know their carrier frequencies and encoding method. I was thinking about the common TSOP17... IR receiver that is made with a selection of 7 carrier frequencies:
  18. Audioguru

    AAA Battery charger

    R9 crudely limits the maximum charging current. D7 and D8 limit the voltage across R9 which causes even higher maximum current which is wrong. D7 and D8 should be removed then the maximum current is limited by R9. C3 prevents LED2 from flickering on and off when the battery is near a full voltage.
  19. Audioguru

    Portable Amp

    Then I guess you also removed the muffler and pollution controls from your car or motorcycle? I see, hear and smell them every day.
  20. Audioguru

    Fan speed control

    We Canadians say the same things, Eh!:)
Top