Circuit Schematic learn

6 Watt Audio Amplifier Schematic Circuit with TDA1519

Some lovers of High Fidelity headphone listening prefer the use of battery powered headphone amplifiers, not only for portable units but also for home "table" applications. This design is intended to fulfill their needs. An improved output driving capability is gained by making this a push-pull Class-B arrangement. Output power can reach 100mW RMS into a 16 Ohm load at 6V supply with low standing and mean current consumption, allowing long battery duration.

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Circuit diagram:

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Parts:Resistors:
P1 = 22K Potentiometer
R1 = 15K Resistor
R2 = 100K Resistor
R3 = 100K Resistor
R4 = 47K Resistor
R5 = 470R Resistor
R6 = 500R Resistor
R7 = 1K Resistor
R8 = 18K Resistor
R9 = 18K Resistor
R10 = 2.2R Resistor
R11 = 2.2R Resistor
R12 = 33R Resistor
R13 = 4.7K ResistorCapacitors:
C1 = 10uF-25V Capacitors
C2 = 10uF-25V Capacitors
C3 = 100nF-63V (PF)
C4 = 220uF-25V Capacitors
C5 = 100nF-63V (PF)
C6 = 220uF-25V CapacitorsSemiconductors:
Q1 = BC560C PNP Transistor
Q2 = BC560C PNP Transistor
Q3 = BC550C NPN Transistor
Q4 = BC550C NPN Transistor
Q5 = BC560C PNP Transistor
Q6 = BC327 PNP Transistor
Q7 = BC337 NPN TransistorMiscellaneous:
J1 = RCA Audio Input Socket
J2 = 3mm Stereo Jack Socket
B1 = 6V Battery Rechargeable
SW1=SPST Slide or Toggle Switch

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Notes:

• For a Stereo version of this circuit, all parts must be doubled except P1, SW1, J2 and B1.
• Before setting quiescent current rotate the volume control P1 to the minimum, Trimmer R6 to maximum resistance and Trimmer R3 to about the middle of its travel.
• Connect a suitable headphone set or, better, a 33 Ohm 1/2W resistor to the amplifier output.
• Switch on the supply and measure the battery voltage with a Multimeter set to about 10Vdc fsd.
• Connect the Multimeter across the positive end of C4 and the negative ground.
• Rotate R3 in order to read on the Multimeter display exactly half of the battery voltage previously measured.
• Switch off the supply, disconnect the Multimeter and reconnect it, set to measure about 10mA fsd, in series to the positive supply of the amplifier.
• Switch on the supply and rotate R6 slowly until a reading of about 3mA is displayed.
• Check again the voltage at the positive end of C4 and readjust R3 if necessary.
• Wait about 15 minutes, watch if the current is varying and readjust if necessary.
• Those lucky enough to reach an oscilloscope and a 1 KHz sine wave generator can drive the amplifier to the maximum output power and adjust R3 in order to obtain a symmetrical clipping of the sine wave displayed.

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Technical data:Output power (1 KHz sine wave):

• 16 Ohm: 100mW RMS
• 32 Ohm: 60mW RMS
• 64 Ohm: 35mW RMS
• 100 Ohm: 22.5mW RMS
• 300 Ohm: 8.5mW RMS

Sensitivity:

• 160mV input for 1V RMS output into 32 Ohm load (31mW)
• 200mV input for 1.27V RMS output into 32 Ohm load (50mW)

Frequency response @ 1V RMS:

• Flat from 45Hz to 20 KHz, -1dB @ 35Hz, -2dB @ 24Hz

Total harmonic distortion into 16 Ohm load @ 1 KHz:

• 1V RMS (62mW) 0.015% 1.27V RMS (onset of clipping, 100mW) 0.04%

Total harmonic distortion into 16 Ohm load @ 10 KHz:

• 1V RMS (62mW) 0.05% 1.27V RMS (onset of clipping, 100mW) 0.1%
• Unconditionally stable on capacitive loads
  

This is a simplest FM transmitter circuit schematic with a single transistor. It build with a very few numbers of components include a transistor, few capacitors, resistors and a small microphone.

In operation, the alarm circuit allows a 0 - 47 second time delay, as determined by the R1 /C1 combination, after the switch is armed to allow the vehicles motion sensor to settle down. This allows you time to get a bag of groceries out of the trunk and not have the hassle of juggling the groceries and the key switch at once.

During the time delay, half of LED1, which is actually a single, bi-colored, three-legged common cathode device, lights green. At the same time, pins 8 and 4 of U2 (a 555 oscillator/timer) are held low by Ul (a 3905 oscillator/timer), causing the alarm to remain silent. Once the delay is over, LED1 turns red, indicating that the circuit is armed.

Auto Alarm Schematic Circuit Diagram

At that point, a ground at pin 2 of U2 forces pin 3 of U2 high, closing the contacts of Kl and sounding the siren for a time duration determined by R4 and C2. Once the time has elapsed, pin 3 is pulled low, Kl opens, and the circuit is again ready to go. The circuit can be manually reset by the simple expedient of opening and closing the key switch. Potentiometer R3 controls the LEDs illumination intensity.

Diode D1 ensures that the green segment of LED1 is fully extinguished when Ql is turned on-which turns the LED to red. Resistors R4 and R5 must be connected to the + V bus. not to pin 7 of Ul. otherwise U2 will mysteriously trigger itself each time the initial delay ends.

This is a 10 way electronic latching switch using just two switches. Each output can be latched on and off independently.

10 Way Electronic Switch Circuit Diagram
Notes
The schematic is shown above, and two switches S1 and S2 are used to control the outputs. The main work is done by U2 a CMOS4017 decade counter divider IC. At switch on, C1 is quickly charged by R4 and a brief reset pulse is applied to to the reset pins of both U1 and U2. This results in U1, a 7 segment display display driver and decade counter showing "zero" on the 7 segment display and pin 3 (which is the output zero) of the 4017 becoming high.

Each time S1 is pressed the clock input of U2 is incremented, by one count and the display and 4017 will cycle through all 10 outputs. A separate reset switch is not provided as the display reads the currently selected output.

When the 4017 is on a particular output, for example zero, then the controlled circuit can be turned on or off using switch S2. To latch the output a type JK flip-flop is used at each of the ten outputs. This works as follows. When the 4017 is at output zero, pin 3 will be high. This enables both JK inputs of the flip flop (U4A at output zero) and the circuit can then be toggled via pulses applied from switch S2. The Q output of each flip-flop drives and NPN transistor and then a small relay. The NPN transistors can be any general purpose type, e.g. 2N2222, BC108, BC548 etc. The relay allows external loads of different voltage and current to this circuit to be controlled.

For clarity, the schematic is drawn with outputs, zero, six and nine shown only. The pinouts for the CMOS ICs 4017 and 4026 can be found in the practical section.

The CMOS 4026 is available at ESR Electronics in the UK.

If required, the external circuits power supply can be used to power the driver transistor and relay. This is shown on output 6, the dotted lines representing the power coming from an external battery. The only other requirement here is that the external circuits common negative terminal is tied to this circuits common chassis (negative) terminal.

A very simple high efficiency Gu10 led light bulbs driver power supply circuit that can be used as a LED driver for GU10 lamp can be designed using this schematic circuit.This high efficiency Gu10 led light bulbs LED driver is designed to drive 12 V at 0.3 A from an input voltage range of 90 VAC to 265 VAC using few external components.

This Gu10 led light bulbs driver power supply uses the LNK605DG IC from the LinkSwitch-II family by Power Integrations. The LNK605DG provides a sophisticated range of protection features including auto restart for open control loop and output short-circuit conditions. As you can see in the circuit diagram , this LED driver require few external electronic components .The LNK605DG Ic from LinkSwitch-II family is an integrated controller plus 700 V power MOSFET intended for use in LED driver or charger applications.

Gu10 LED Light Bulbs Driver Circuit Diagram



The rectified and filtered input voltage is applied to one end of the primary inding of T1 transformer and the other side of the transformer’s primary winding is driven by the integrated 700 V power MOSFET in U1. The leakage inductance drain voltage spike is limited by an RCDR clamp consisting of D1, R3, R4, and C3.

The secondary of the transformer is rectified by D3 ( a Schottky barrier type was selected for higher efficiency) and filtered by C7. Resistor R1 and C6 dampen high frequency ringing and reduce the diode voltage stress The T1 transformer must have 30 turns from NC to pin1( with 0.221 mm copper wire) , 80 turns from pin1 to pin 2 ( with 0.15 mm copper wire) , 15 turns from pin7 to pin8 ( with 0.4mm copper wire) and 16 turns from pin A to pin B (using 0.2mm copper wire ) .

A very simple light alarm schematic circuit project can be designed using some common electronic parts, as you can see in the circuit diagram bellow . This light alarm schematic circuit project will sound as soon as the drawer is opened and light falls on the Darlington phototransistor. The output alarm may be redesigned to activate a relay or triac. This simple light alarm schematic circuit project use a MAL12 LDR photoresistor as a sensor .

Light Alarm Schematic Circuit diagram

The 14011 quad , 2 input, NAND gate is wired up to oscillate when the input to it goes high, that is the BC557 transistor turns on after light is detected by the MAL12. The oscillating output from the 14011 turns the BC547 on and off , making the buzzer to sound. After the alarm has started and it is put back into dark conditions , alarm will continue to sound for about 3 - 5 seconds. This is due to the 1uF capacitor and 4M7 resistor which keep the input to the 14011 high .

The circuit is very simple and must be powered from a simple 9 volts DC power supply or a 9 volt battery .

This circuit is a Digital Radar Speedometer. It allows us to evaluate the speed of any object moving, especially cars and other vehicles. The speed is calculated in kilometers per hour (KPH). Its display has three digits. This radar works with the laser reflexion. It sends laser radiation to the object and this object reflects the laser radiation to the radar. To evaluate the speed of a vehicle, we must be in front of it. In other words, the vehicle must come in our direction. The front of the radar must point the front of the vehicle. The radar has the shape of a pistol. In this radar, it has a laser LED and a laser diode. Both have a lens.

Digital Radar Speedometer Circuit Diagram

The laser LED can send a spot of light to a distance of 90 m (295 ft). Its very important that the distance range of the laser LED is 90 m, if not, the speed will not be calculated properly. The laser diode, which receives the light signal by the laser LED, must be able to detect the light which is same color as that emitted by the laser LED. The laser diode and the laser LED must be placed one beside the other. They are protected by a tinted pane. They must be placed at the front of the radar and point the outside. The radar is powered by a 9V battery and it has a SPST switch to control its power state.

The display, or the speed indicator, is placed at the rear of the radar, just on the right of the overload LED indicator. All the logic components of the circuit must be of the 74AS series and TTL type. Because they have short time of response (less than 1.7 ns) and have high frequency supports (more than 200 MHz). The radar can evaluate the speed of an object moving between 0 to 999 km/h. After this speed, the overload LED indicator will turn on and the "999" will still displayed. The radar displays the speed during 3 seconds, after this time, it displays "zero" (0).

In the circuit, two op amps (half of an LM324 quad op amp) and an SCR are direct coupled in a de-voltage monitoring circuit. Op-amp U1-a is configured as a voltage follower, which feeds the bridged inputs of the second op amp, Ul-b. A resistor/capacitor combination (R2/C1) connected to the negative input of U1-b forms an RC time-delay circuit.

Glitch Detector Circuit Schematic

As long as there is no change in the de-voltage level at either of U1-bs inputs, its output is near zero. If a voltage glitch occurs, the RC timing circuit will delay the voltage change at the op amps inverting input, causing its output to go high, triggering SCR1 and causing LED1 to light. The circuits sensitivity allows it to detect voltage changes in the millivolt range. Pressing S1 diverts the SCRs holding current to ground, causing it to turn off and reset the circuit.