120V AC Line Powered LED

The following circuit diagram shows you about how to powering a LED (or two) from the 120 volt AC line applying | working with a capacitor to drop the voltage together with a little resistor to limit the inrush electric current. Considering that the capacitor need to pass current in both directions, a modest diode is connected in parallel using the LED to supply a path for the negative half cycle and also to limit the reverse voltage across the LED. A second LED using the polarity reversed could be subsituted for the diode, or perhaps a tri-color LED might be put to use which would appear orange with alternating current. The circuit is fairly efficient and draws only about a half watt from the line. The resistor value (1K / half watt) was chosen to limit the worst case inrush electric current to about 150 mA which will drop to much less than 30 mA in a millisecond as the capacitor charges. This appears to be a secure value, I've switched the circuit on and off several times without having harm to the LED. The 0.47 uF capacitor has a reactance of 5600 ohms at 60 cycles so the LED current is about 20 mA half wave, or 10 mA average. A bigger capacitor will boost the electric current along with a smaller 1 will lessen it. The capacitor should be a non-polarized kind having a voltage rating of 200 volts or a lot more.

The lower circuit is an demonstration of obtaining a low regulated voltage from the AC line. The zener diode serves as a regulator and also supplies a path for the negative half cycle electric current when it conducts inside the forward direction. In this example the output voltage is about 5 volts and will give over 30 milliamps with about 300 millivolts of ripple. Use caution when operating any electronic circuits hooked up straight to the AC line.

120V AC Line Powered LED circuit source:
http://www.bowdenshobbycircuits.info/page10.htm#lineled.gif

14W Audio Amplifier Circuit

This Amplifier circuit designed by Mike Ellis at 1999. The amplifier capable to deliver up to 14W power audio output. The pre-amp circuit already designed in the circuit and direct connected to the amplifier modul.

Here the 14W Audio Amplifier schematic diagram:

For detailed explanation about this 14W amplifier circuit, visit the following page:
http://michaelgellis.tripod.com/audioamp.html

Video Amplifier Circuit based LH0032

The following is the schematic diagram of Video Amplifier circuit, built based on LH0032, a high speed op-amp applications.

Video Amplifier Parts List:
R1 = 15Kohm+15Kohm
R2,R3,R4 = 10Kohm
R5,R6,R7,R8,R9 = 1Kohm
R10 = 820ohm
R11 = 1Mohm
R12 = 100ohm trimmer
R13,R15 = 47ohm
R14 = 10Kohm
C1 = 10uF 63V MKT
C2,C4 = 100nF 63V
C3 = 4.7pF ceramic
IC1 = LH0032
S1 = 1X2 mini switch
S2 = 1X6 sel.
J1,J2 = BNC connector

The LH0032 are very high speed general purpose operational amplifiers exhibiting 70 MHz bandwidths, 500 V/μs slew rates and 100 to 300 ns settling time to 0.1%. The LH0032 has the added advantage of FET input characteristics.

Fading LEDs Circuit

The following diagram is the schematic diagram of fading LEDs circuit. This kind of circuit runs two LED strips in pulsing mode, i.e. one LED strip goes from off state, lights up gradually, then dims little by little, and so on. while one other LED strip does the contrary.

Components part:

R1, R2 = 4K7 R3 = 22K R4 = 1M * R5 = 2M2 * R6, R10, R11, R14, R15 = 10K R7, R8 = 47K Trimpot * R9, R13 = 27K R12, R16 = 56R

C1 = 1µF C2 = 100µF/25V D1-D4 etc = 5 or 3mm LEDs * IC1 = LM358 Q1, Q2 ,Q4 = BC327 Q3, Q5, Q6 = BC337 SW1 = SPST miniature Slider Switch B1 = 9V PP3 Battery

Circuit Works:

The IC1 contains two Op-Amps circuit which will be used to generate triangular wave form.. The rising and falling voltage obtained at pin #7 of IC1 drives two complementary circuits formed by a 10mA continual current source (Q1, Q2 and Q5, Q6) and driver transistor (Q3 and Q6).
R4, R5 & C1 are the timing components: the total period can be varied changing their values. R7 & R8 vary the LEDs brightness.

Fading LEDs Circuit Notes:

• For those whishing to avoid the use of trimmers, suggested values for 9V supply are: R4=3M9, R9 & R13=47K and trimmers replaced by a short.
• Whishing to use a wall-plug adapter instead of a 9V battery, you can supply the circuit at 12V, allowing the use of up to 6 LEDs per strip, or at 15V, allowing the use of up to 7 LEDs per strip.
• In this case, the value of the trimmers R7 & R8 should be changed to 100K.

Fading LEDs Circuit Source: RedCircuits

50W Amplifier Circuit based ICL8063 + 2N3055

50W Amplifier Circuit, built based ICL8063 as power transsistor driver and 2N3055 as main power amplifier component.

50W Amplifier Circuit based ICL8063 + 2N3055 schematic diagram:

Parts List:

R1 = 200 Ohm R2 = 200K R3 = 30K R5 = 1K R6 = 5K R7, R10 = 1 Meg R8,R9 = 0.4 Ohm/5Watt R11 = 10K Potensiometer R12,R13 = 51K R14 = 47K C1 = 100uF/35V C2 = 0.011uF C3 = 3750pF C4,C6 = 1000pF

C5,C7,C8 = 0.001uF C9 = 50pF C10 = 0.3uF C11,C12 = 10.000uF/50V U1,U2 = 741 Op Amp U3 = ICL8063 Audio Amp Transister Driver Q1 = 2N3055 NPN Power Transistor Q2 = 2N3791 PNP Power Transistor BR1 = 250 V 6 Amp Bridge Rectifier T1 = 50V Center Tapped 5 Amp Transformer S1 = SPST 3 Amp Switch S2 = DPDT Switch F1 = 2 Amp Fuse SPKR1 = 8 Ohm 50W Speaker

Circuit Notes:

• Distortion is much less than 0.1% up to 100HZ and increases to about 1% at 20kHz.
• 50V CT transformer might be difficult to find, you may use 45V or 32V CT transformer.
• Q1 and Q2 should be use heatsinks to prevent over heating.

50W Amplifier Circuit based ICL8063 + 2N3055 source page

LM3886: 68W Power Amplifier

This is a good amplifier circuit taken from electronic-diy.com. Built based LM3886, the amplifier capable to deliver up to 68W audio output.

Parts List:

R1 = 10K Ohms R2 = 10 Ohms 2W see text R3 = 10 Ohms R4 = 47K Ohms R5 = 220K Ohms R6 = 10K Ohms R7 = 100K Ohms L1 0,7uH IC1 LM3886

C1 = 100NF C2 = 100NF C3 = 100NF C4 = 100UF C5 = 100UF C6 = 4,7UF C7 = 100UF C8 = 1UF

The amplifier should be supplied by +34 and –34 volts. R2 and L1 is a resistor of 10 ohms / 2 watt coiled with 10 to 12 you exhale of enameled thread AWG 20.

68W Power Amplifier circuit diagram based LM3886

25W Power Amplifier with MOSFET IRF530/IRF9530

This is a MOSFET powered amplifier circuit. The circuit output will be 25 Watt RMS @ 8 Ohm (1KHz sine wave) with frequency response of 30Hz to 20KHz -1dB.

Components Part:

R1, R4 = 47K R2 = 4K7 R3 = 1K5 R5 = 390R R6 = 470R R7 = 33K R8 = 150K R9 = 15K R10 = 27R R11 = 500R R12, R13, R16 = 10R R14, R15 = 220R R17 = 8R2 - 2W Resistor R18 = R22 - 4W Resistor (wirewound)

C1 = 470nF/63V C2 = 330pF/63V C3, C5 = 470µF/63V C4, C6, C8, C11 = 100nF/63V C7 = 100µF/25V C9 = 10pF/63V C10 = 1µF/63V Q1-Q5 = BC560C Q6 = BD140 Q7 = BD139 Q8 = IRF530 Q9 = IRF9530

Circuit Notes:

• This circuit dual polarity power supply to supply the amplifier.
  
• This audio amplifier can be directly connected to CD players, tuners and tape recorders. Just add a 10K Log potentiometer (dual gang for stereo) along with a switch to cope using the different sources you need.
• Q6 and Q7 must have a small U-shaped heatsink.
• Q8 and Q9 must be mounted on heatsink.
• Adjust R11 to set quiescent current at 100mA (best measured with an multimeter connected in series to Q8 Drain) with no input signal.
• A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of R1, R4, R9, C3 to C8. Connect C11 to output ground. Then connect separately the input and output grounds to power supply ground.

Electronic Chirping Canary Circuit

Well, for those of you who want to make a small project, this alarm may be an option for you. This circuit will generate the canary chirping sound. The chirp sound of a canary is generated by the oscillation process by resistor R1 and capacitor C1. The capacitor, having a capacitance value of 100 uF, is charging through the resistor, having a resistance of 4.7 K ohms. During this stage, R1 is the bias for the transistor making it operate in the cut off. When the transistor is in cut off mode, the base-emitter voltage is very minimal for any considerable current to flow. This mode triggers the oscillation to end but will start again once the capacitor discharges across the transmitter’s base-emitter circuit.

The frequency of the chirp may be modified by changing the values of the resistor and capacitor. The charging of the capacitor occurs when operating the push button switch. By releasing the button, the chirping runs quicker whilst the oscillation weakens.

The loudspeaker is being driven and coupled to the circuit by the miniature audio transformer of LT700 which having a frequency of 1 kHz. This circuit can be supplied with 9V battery.

Electronic chirping canary circuit source: http://www.elecpod.com/circuit/av/2010/03011410.html