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  1. Rleo6965

    Schematic to reality conversion

    Made in China Multimeter was very cheap in Philippines. Buy one and this will save you from mistakes and time to finish your project.
  2. Rleo6965

    IC 555

    Yes. Try this link. Waveform was included. It might easier for you to understand. http://www.kpsec.freeuk.com/555timer.htm
  3. Rleo6965

    IC 555

    Hi vick5821, I suggest that concentrate learning electronics by its symbol or block diagram. Just remember its inputs, control ,output and function of IC or circuit. It's easier to learn electronics this way. Then slowly learn simple transistor circuits. I'm sure you can you can interpret or...
  4. Rleo6965

    IC 555

    If you look closely of the NE555 internal schematic diagram. You will notice that upper transistor Q22 was connected to Pin 8 +VCC and Pin 3 output. When NE555 was triggered Q22 was turn on. Its collector and emitter will conduct that connect Pin 8 +Vcc to Pin 3 near the +VCC voltage. Probably...
  5. Rleo6965

    IC 555

    I arranged the circuit diagram in such a way that LED will Light on when pin 3 was at High Voltage state. When the output pin 3 goes high. This means upper internal transistor will short pin 3 to pin 8 . Thus causing current from 4.5 battery thru pin 8, pass upper internal transistor to pin 3...
  6. Rleo6965

    IC 555

    See picture. Pin 3 Low output means the internal transistor shorting pin 3 to ground. Thus pin 3 shorting to ground completed the circuit of LED and turns on. Follow the current flow path from + side of 4.5V battery flow thru LED and R1 to pin 3 , internal transistor of ne555, ground then last...
  7. Rleo6965

    IC 555

    The NE555 was in astable or oscillator mode. LED was wired to pin 3 in such a way that when ne555 was pin 3 output was low ( sink state ). The LED will turn on.because the internal totem pole output lower transistor of ne555 was turn on thus shorting pin 3 output to ground. It's like placing a...
  8. Rleo6965

    IC 555

    I assume that you already have google about NE555 circuit and its application. Internally NE555 have flip flop circuit that its output was connected to open collector discharge transistor pin 7 and totem pole output pin 3. This flip flop must be reset or momentarily held low voltage input pin...
  9. Rleo6965

    IC 555

    Initially the ne555 pin 3 output voltage was low or sink status. Once a trigger voltage or hi to low going voltage ( lower than 1/3 of vcc voltage ) applied or signal pulse to the trigger input pin 2. Pin 3 output of ne555 will go high until capacitor gradually charging voltage reached...
  10. Rleo6965

    IC 555

    Discharging
  11. Rleo6965

    Schematic to reality conversion

    If your having problem sourcing MPF102 or equivalent. Try omit or removed mpf102, 1M5, 3K9and 47n. You can directly connect your input signal on top terminal of 10K volume control. This might save you time and components for building your amp. You can test your amp without the signal from...
  12. Rleo6965

    5v regulator L7805

    or ground terminal of LM7805 was not connected to ground. Therefore LM7805 act as resistor when measuring its Output Terminal (7V).
  13. Rleo6965

    5v regulator L7805

    Accident does happen in building projects in electronics. Even simple circuits. But it does help us to learn and not to repeat the same mistake.:)
  14. Rleo6965

    Schematic to reality conversion

    I hope your not in Basilan.:D Already inquired of 6 watts audio amplifier kit in Alexan . Its only P130.00 or almost USD$3. You can send email to Alexan main office and inquire for payment and delivery arrangement.. Hope this help.:)
  15. Rleo6965

    5v regulator L7805

    Can you share solving your 7805 problem.? Just curious. :)
  16. Rleo6965

    Connection of Feedback and noise?

    Sorry for wrong choice of word time constant. I should mentioned High Pass Filter. http://en.wikipedia.org/wiki/File:Active_Highpass_Filter_RC.png
  17. Rleo6965

    Connection of Feedback and noise?

    An rc circuit with same time constant of noise will allow only the noise signal pass ( not the audio ) and amplified and inverted if necessary and feedback to the input of amplifier. I can't find rc noise feedback circuit in the internet. But i'm sure I learned that in our school here in...
  18. Rleo6965

    Schematic to reality conversion

    If you live in Metro Manila in Philippines. Try buy 2-Watt Utility Amplifier w/ HC851 from Alexan Commercial. Here there link. http://www.alexan.com.ph/ Almost all my electronics parts was bought in Alexan Commercial. Raon , Manila.
  19. Rleo6965

    Need help understanding importance of Inductance

    It won't recharge filter capacitor because emf current was smaller than charge current of capacitor.
  20. Rleo6965

    Dummy load for amplifier

    It's a good practice to have a dummy load resistor for temporary load than an expensive speaker. Resistor was cheaper than the speaker and won't disturb your neighbor if your testing the amplifier for higher volume. Still computerlen have a good practice to place lamp in series with amplifier...
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