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  1. Audioguru

    FM Antenna Connection

    I forgot to say that an antenna amplifier is usually overloaded by strong local stations or its output overloads the radio causing them to be smeared all over the dial of the radio.
  2. Audioguru

    FM Antenna Connection

    Connect the amplifier's adapter's red wire to the radio antenna screw and connect the black wire to the radio's ground.
  3. Audioguru

    Brake light flasher (555 - based) circuit works on breadboard, but not PCB

    I think they painted the board almost black so that you cannot see their mistakes and so that they can use white text. I have never seen a pcb before that does not have its tracks very visible.
  4. Audioguru

    R/C Relay Driver

    1) The opamp has no power supply. 2) Since the LED lights then the base-emitter of the transistor is blown up or the pins on the transistor are connected wrong. A LED needs at least 1.5V but the maximum base-emitter voltage of a BC547 is about 0.8V so if the transistor is good then the LED will...
  5. Audioguru

    Circuit validation & improvement

    I understand why you want to use more battery cells in series than you need. They will make heat and steady power. A 34V battery can provide regulated 24V at full current until the battery is dead but a 24V battery provides full current only for a few minutes then the current drops as the...
  6. Audioguru

    LED headlight build

    The 50W monster headlight has 48 extremely bright LEDs as a floodlight, not for a headlight on a motor vehicle. A vehicle low beam is supposed to be a spotlight aimed at the ground with the bright part blocked from shining ahead. The monster LED s has a very wide viewing angle and is much...
  7. Audioguru

    LED headlight build

    The circuit was designed to drive an ordinary little 20mA LED not a monster LED headlight. R2 limits the current to almost nothing (the schematic wrongly shows 4700 ohms but 47 ohms is used in the video) and the maximum output current from a 555 IC is only 200mA (your headlight draws up to...
  8. Audioguru

    Circuit validation & improvement

    My RC airplanes use the entire Li-Po battery voltage for the ESC, not a much lower regulated voltage that wastes battery power making heat.
  9. Audioguru

    Interfering circuits

    An LMC555 and a TLC555 are also Cmos versions of the 555. Hee, hee. Texas Instruments make both of them now.
  10. Audioguru

    Active narrow band-pass filter design

    Most opamps and your signal source cannot drive those very low resistor values. A multiple feedback bandpass filter has very gradual cutoff slopes (6dB per octave) about the same as the bass and treble controls on your stereo. My simulation shows a peak at 7kHz and the response is -3dB at...
  11. Audioguru

    Interfering circuits

    I agree that many opamps go crazy when their power supply is not bypassed (decoupled) with some suitable capacitance. The TL082 and many other opamps oscillate at a high frequency when driving the capacitance of a shielded output cable a meter long or more. Then a 100 ohm isolation resistor...
  12. Audioguru

    Newcomer to handling MOSFETS....

    Cmos ICs have input protection against some (but not all) static electricity. Most Mosfets don't.
  13. Audioguru

    Need Id Of Electronic Component

    Your first photos were very blurry. Your second photos have the part in the dark. Please tell us the text that is written on it.
  14. Audioguru

    Circuit validation & improvement

    RC planes use lightweight Li-PO batteries that can provide 50A directly without dropping the voltage. Your circuit has an output voltage of 24V but the 0.7 ohm resistor in series with the motor limits the current a lot. The transistors and resistor waste a lot of battery power making heat. RC...
  15. Audioguru

    CCFL lamp tester

    All the fluorescent light tubes and compact bulbs on Canada have a filament at each end.
  16. Audioguru

    Motion sensing mouse trap

    Maybe the mouse will hear the solenoid and run away before the box has fallen. Then you trap the mouse in the box. When you lift the box to grab the mouse it runs outta there and is back in your house.
  17. Audioguru

    Garden Lights, Disable the multi-function.

    A 2400mAh battery will be fine to see if it takes more charge to power the circuit longer.
  18. Audioguru

    When and why would you use a capacitor?

    A capacitor in series blocks DC but passes AC. If the capacitance is low then it reduces low frequencies but passes high frequencies. Then it is a simple highpass filter. A capacitor to ground following a series resistor reduces high frequencies. Then it is a simple lowpass filter.
  19. Audioguru

    rewiring an emergency light with tubes for LED strips

    You need a power supply or battery that produces enough DC voltage and current for your LED strips. Most LED strips use 12VDC but you must add up the current for the number of strips that you will use.
  20. Audioguru

    Garden Lights, Disable the multi-function.

    If the solar panel has extra power for charging then using a modern Western Ni-MH battery cell that has at least double the capacity of the cheap Chinese cell would work. Most modern battery companies use the Japanese Eneloop method today. They are pre-charged and hold a charge for about one...
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