Dual Power Supply dan inverting convert circuit

Dual supply for this circuit.

   
A  +15V/-15V dual supply for powering this tone control circuit is shown below. Bridge D1 can be made using four 1N4007 diodes.  This supply is unregulated and its quite fine for this circuit. Anyway  if you need to have a regulated one please inform me.
Power supply for tone control circuit
Notes.
Circuit can be assembled on a vero board or perf boad. Any way a PCB is the best option.
Use +15/-15V DC dual supply for powering the circuit.
IC1 TL072 must be mounted on a holder.
By changing the value of R1 and R2 the voltage gain (Av) of the preamplifier stage can be changed

Read more: http://www.circuitstoday.com

Inverting converter circuit.
    
Inverting converter circuit using uA78S40
An inverting converter is a circuit which reverses the polarity of a given input voltage. For example if 5V DC is applied at the input of an inverting converter, the output voltage will be -5V DC. A 15V inverting converter circuit using uA78S40 is shown above. Ct (in the circuit C1) is the timing capacitor for the ICs internal oscillator, C3 is the input filter capacitor and C2 is the output filter capacitor. Both C2 and C3 must be rated at least 25V. Resistors R1 and R2 forms a feedback network which feed backs a portion of the output voltage to the non inverting input of the Ics internal comparator. R2 and R1 can be used to set the output voltage. Transistor Q1 is the external switching transistor. The collector terminals of the internal driver and switching transistors are shorted and connected to the base of the external switching transistor through resistor R3.

Notes.
uA78S40 must be mounted on a holder.
Peak output current of uA78S40 is 1.5A.
1N5822 is a 3A Schottky diode. Do not replace it with an ordinary PN junction diode.
Vout = 1.25 (1+ (R2/R1)) for step down converter.
Vout = (1.25R2) / (R1) for inverting converter.
Switching Regulator Vs Linear regulator.
The controlling element for a linear regulator is an active device ( either a BJT or FET) operating inside its active region.In a linear regulator the difference between the input voltage and output voltage is dissipated as heat by the controlling element. This reduces the power efficiency. The controlling element requires a larger heatsink .

For a switching regulator the controlling element which is an electronic switch (a transistor or thyristor) has only two states, either ON (completely conducting) or OFF (completely open). This means that no power is wasted across the switching element and this result in better power efficiency. A well designed switching regulator can have up to 85% efficiency. The controlling element requires a smaller heatsink.

Power Supply ACMETIC

Power Supply ACMETIC

Tegangan searah berdenyut yang diperoleh dari penyearah D1…D4 mempunyai harga puncak 310 V. Tegangan ini diberikan ke cerat dari MOSFET daya T1 melalui resistor pembatas R9. Sebuah rangkaian pengendali menjamin MOSFET hanya akan menghantar selam waktu yang singkat sebelum dan sesudah tegangan jala-jala melewati nol. Selama waktu ini tegangan searah berdenyut tidak melampau 5 V. Dalam waktu singkat yang sama Kondensator perata C2 akan termuati ; selama waktu sesudahnya ia memberikan arus keluaran. Akibatnya Kondensator tersebut harus berharga sangat besar 10.000 µF. denyut-denyut arus beban dalam waktu singkat mempunyai harga puncak dalam orde 4 A!

Kemantapan tegangan keluaran pada dasarnya tergantung pada beban. Arus keluaran maksimal bisa 110 mA. Catu untuk rangkaian pengendali diperoleh dari Resistor R2., Kondensator C1 dan dioda D5 dan D6. Rangkaian pengendali merupakan penanding jendela yang terbentuk dari tiga op-amp.

Source belajarelektronika.com

POwer Ampli 30 Watt

POWER AMPLI 30 WATT

This project was a sort of challenge: designing an audio amplifier capable of delivering a decent output power with a minimum parts count, without sacrificing quality. The Power Amplifier section employs only three transistors and a handful of resistors and capacitors in a shunt feedback configuration but can deliver more than 18W into 8 Ohm with 0.08% THD @ 1KHz at the onset of clipping (0.04% @ 1W - 1KHz and 0.02% @ 1W - 10KHz) and up to 30W into a 4 Ohm load.

To obtain such a performance and to ensure overall stability of this very simple circuitry, a suitable regulated dc power supply is mandatory. This is not a snag because it also helps in keeping noise and hum of the preamp to very low levels and guarantees a predictable output power into different load impedance. Finally, as the amplifier requires only a single rail supply, a very good dc voltage regulator capable of supplying more than 2 Amps @ 40V can be implemented with a few parts also.

---

Circuit diagram:

Audio Power Amplifier Circuit Diagram

---

Power Amplifier Parts:

R1 = 2K2 1/4W Resistor
R2 = 27K 1/4W Resistor
R3 = 2K2 1/2W Trimmers Cermet
R4 = 2K2 1/2W Trimmers Cermet
R5 = 100R 1/4W Resistor
R6 = 1K 1/4W Resistor
R7 = 330R 1/4W Resistors
R8 = 330R 1/4W Resistors

C1 = 22µF 25V Electrolytic Capacitor
C2 = 47pF 63V Polystyrene or Ceramic Capacitor
C3 = 100µF 50V Electrolytic Capacitors
C4 = 100µF 50V Electrolytic Capacitors
C5 = 2200µF 50V Electrolytic Capacitor

Q1 = BC550C 45V 100mA Low noise High gain NPN Transistor
Q2 = IRF530 100V 14A N-Channel Hexfet Transistor (or MTP12N10)
Q3 = IRF9530 100V 12A P-Channel Hexfet Transistor (or MTP12P10)

---

Setting up the Power Amplifier:

1. The setup of this amplifier must be done carefully and with no haste:
2. Connect the Power Supply Unit (previously tested separately) to the Power Amplifier but not the Preamp: the input of the Power Amplifier must be left open.
3. Rotate the cursor of R4 fully towards Q1 Collector.
4. Set the cursor of R3 to about the middle of its travel.
5. Connect a suitable loudspeaker or a 8 Ohm 20W resistor to the amplifier output.
6. Connect a Multimeter, set to measure about 50V fsd, across the positive end of C5 and the negative ground.
7. Switch on the supply and rotate R3 very slowly in order to read about 23V on the Multimeter display.
8. Switch off the supply, disconnect the Multimeter and reconnect it, set to measure at least 1Amp fsd, in series to the positive supply (the possible use of a second Multimeter in this place will be very welcomed).
9. Switch on the supply and rotate R4 very slowly until a reading of about 120mA is displayed.
10. Check again the voltage at the positive end of C5 and readjust R3 if necessary.
11. If R3 was readjusted, R4 will surely require some readjustment.
12. Wait about 15 minutes, watch if the current is varying and readjust if necessary.
13. Please note that R3 and R4 are very sensitive: very small movements will cause rather high voltage or current variations, so be careful.
14. Those lucky enough to reach an oscilloscope and a 1KHz 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.

---

Preamplifier Section:

---

The Preamp sensitivity and overload margin were designed to cope with most modern music program sources like CD players, Tape recorders, iPods, Computer audio outputs, Tuners etc. The source selecting switches and input connectors are not shown and their number and arrangement are left to the constructor's choice. To obtain a very high input overload margin, the volume control was placed at the preamp input.

After a unity gain, impedance converter stage (Q1) a negative-feedback Baxandall-type Bass and Treble tone control stage was added. As this stage must provide some gain (about 5.6 times) a very low noise, "bootstrapped" two-transistors circuitry with FET-input was implemented. This stage features also excellent THD figures up to 4V RMS output and a low output impedance, necessary to drive properly the Mini-MosFet Power Amplifier, but can also be used for other purposes.

---

Circuit diagram:

Preamplifier Circuit Diagram For Power Amplifier

---

Preamplifier Parts:

P1 = 50K - Log. Potentiometer
P2 = 100K - Linear Potentiometers
P3 = 100K - Linear Potentiometers
(twin concentric-spindle dual gang for stereo)

R1 = 220K - 1/4W Resistor
R2 = 100K - 1/4W Resistor
R3 = 2K7 - 1/4W Resistor
R4 = 8K2 - 1/4W Resistors
R5 = 8K2 - 1/4W Resistors
R6 = 4K7 - 1/4W Resistor
R7 = 2K2 - 1/4W Resistors
R8 = 2K2 - 1/4W Resistors
R9 = 2M2 - 1/4W Resistor
R10 = 47K - 1/4W Resistor
R11 = 47K - 1/4W Resistor
R12 = 33K - 1/4W Resistor
R13 = 2K2 - 1/4W Resistors
R14 = 470R - 1/4W Resistor
R15 = 10K - 1/4W Resistor
R16 = 3K3 - 1/4W Resistor (See Notes)

C1 = 470nF - 63V Polyester Capacitors
C2 = 470nF - 63V Polyester Capacitors
C3 = 47nF - 63V Polyester Capacitors
C4 = 47nF - 63V Polyester Capacitors
C5 = 6n8 - 63V Polyester Capacitors
C6 = 6n8 - 63V Polyester Capacitors
C7 = 10µF - 63V Electrolytic Capacitor
C8 = 22µF - 25V Electrolytic Capacitors
C9 = 470nF - 63V Polyester Capacitors
C10 = 22µF - 25V Electrolytic Capacitors
C11 = 470µF - 25V Electrolytic Capacitor (See Notes)

Q1 = BC550C - 45V 100mA Low noise High gain NPN Transistors
Q2 = 2N3819 - General-purpose N-Channel FET
Q3 = BC550C - 45V 100mA Low noise High gain NPN Transistors

---

Power Supply Section:

---

A very good and powerful Regulated Power Supply section was implemented by simply adding a PNP power transistor to the excellent LM317T adjustable regulator chip. In this way this circuit was able to deliver much more than the power required to drive two Mini-MosFet amplifiers to full output (at least 2Amp @ 40V into 4 Ohm load) without any appreciable effort.

---

Circuit diagram:

Regulated Power Supply Circuit Diagram

---

Power Supply Parts:

R1 = 3R9 - 2W Resistor
R2 = 22R - 1/4W Resistor
R3 = 6K8 - 1/4W Resistor
R4 = 220R - 1/4W Resistor
R5 = 4K7 - 1/2W Resistor

C1 = 4700µF - 50V Electrolytic Capacitor
C2 = 100nF - 63V Polyester Capacitors
C3 = 10µF - 63V Electrolytic Capacitor
C4 = 220µF - 50V Electrolytic Capacitor
C5 = 100nF - 63V Polyester Capacitors

D1 = Diode bridge - 100V 4A
D2 = 1N4002 - 200V 1A Diode
D3 = LED - Any type and color

SW2 = SPST - Mains switch
IC1 = LM317T - 3-Terminal Adjustable Regulator
PL1 = Male Mains plug with cord

Q1 = TIP42A - 60V 6A PNP Transistor
T1 = 230V Primary, 35-36V (Center-tapped) Secondary,
50-75VA Mains transformer (See Notes)

---

Notes:

• Q2 and Q3 in the Power Amplifier must be mounted each on a finned heatsink of at least 80x40x25mm.
• Q1 and IC1 in the Regulated Power Supply must be mounted on a finned heatsink of at least 45x40x17mm.
• A power Transformer having a secondary winding rated at 35 - 36V and 50VA (i.e. about 1.4Amp) is required if you intend to use Loudspeaker cabinets of 8 Ohm nominal impedance. To drive 4 Ohm loads at high power levels, a 70 - 75VA Transformer (2Amp at least) will be a better choice. These transformers are usually center tapped: the central lead will be obviously left open.
• For the stereo version of this project, R16 and C11 in the Preamp will be in common to both channels: therefore, only one item each is necessary. In this case, R16 must be a 1K5 1/2W resistor. The value of C11 will remain unchanged.

Source extreme circuit.