Showing posts with label Amplifier. Show all posts
Showing posts with label Amplifier. Show all posts
Tuesday, April 2, 2013
Solve buzzing and noise on the amplifier circuit
Power amplifiers that we sometimes raises a raft of small drone as groundingless than perfect.The following are some ways to cope with the hum of the power amplifier:
1. Keep sensitive circuits of the transformer, casing dimensions are not too small.One blog even suggested to use two-bok, bok special one for the transformer. For the toroid transformer or amplifier with a large transformer, should only contain a series of power amps, with no tone control.
2. Change the position of the transformer, side by side into the lower side (the transformer is high) withfacing a series of sensitive posts
3. Use a spacer on each PCB board as high as half the height of the transformer, eg as high as 2.5 cm or more so that the PCB board parallel to the core / center of the transformer, here the effect of the weakest fields.
4. We recommend using a stereo module instead of two mono modulesThis avoids wiring errors. If forced to, try to sizecable between the right and left modules as long and as short as possible.
5. Should take the ground path for the speaker of ct ct elco instead of the transformer,if the board pcb mounted two big elco (like elco power supply), takeground path of the speakers here, and check to hear!
6. Power supply for radio (TX or RX) is very sensitive, use a capacitor4x100nf, 4 pairs of these capacitors in parallel to each mem-diode (bridge).
7. At the tone control circuit IC op-amp that uses a symmetric power supply,sufficient ground wiring is taken from the signal ground wires only. shouldIC power supply (7812) installed near the main power supply, notmounted near the tone control.
8. Always use a stereo cable shrouded perfect (color stereo cablered-white-covered ground and wrapped in transparent skin.
9. For power supply, use capacitors of 2200uF per ampere elco
10. Zoom and ground wires as short as possible, especially a pair of elco (ct line between elco) power supply (can be tried for the amplifier blazer)
11. For the amplifier should be mounted to the computer casing when not in the ground soil is diground PC casing soil
12. Pairs of each kit to the circuit without passing groundnya nut / baud / spacer. Do not let the existing ground line at the hole pcb connected to the casing / box. Do not follow this ground. ground attached to the casing should have one. if necessary use a plastic spacerovercome the noise:
1. Use the active component (IC) that qualified as TL084, TL074, notLM324. LM324 any brand of noise. TL084 is more guaranteed authentic yellow (ST), not white. For now, the IC TL084 is printed white-work unstable frequencyhigh (treble breaks and more noise). For IC 4558 (NE5532) use plain white silk screening JRC4558D or TL072 - TL082 yellow, LF353 noise. LM741 (NE5534) can be replaced with the Hitachi HA17741, LF351 noise may also, has never been tried.we do not have to look for the brand and the price is more expensive because it is the most low noise.
2. If necessary, the circuit power amplifier OCL, lowering its gain by lowering the value ofresistor in the path gain from 33k to 22k speaker, mimics the gain-clone lower amplifier noise.
3. Should simplify the circuit, the circuit is too complex is more susceptible to noise and interference.
4. Should then potentio / volume mounted on the input-power amplifier, such as professional amplifier without tone control.
Wednesday, February 1, 2012
CLASS AB BJT 100W Hi-End AUDIO AMPLIFIER CIRCUITS
Symasym5, is a "cute" power amplifier, designed with quality but still low price in mind. This resulted in a ClassAB BJT amplifier, using only TO92 transistors for input and VAS, with a reasonable part count. The topology used is well known and consist of a single diffamp for input, plus a 2nd diffamp with current mirror for VAS. This is followed by normal darlington EF outputstage using modern high beta devices. The circuit uses large amounts of feedback over the whole audioband and an unconventional feedback compensation scheme. Right now symasym is designed to be driven directly from a CD/DVD-player, simply place a 22k poslog stereo pot between player and symasym. (as voltage divider)Update
The at least change is to reduce C14 from 22pF to 10pF, but i recommend to follow Pavel's advice.
I recommend C14 with 10pF also for MJLs, this increases safety margin.
Do not forget to read Pavel's Review! A very promising evaluation of the qualities to be expected from symasym. Thanks Pavel !
Another update are the resistors R31/32 to be increased from 22ohm to 47ohm. Symasym5_3 is an update of v5.2, with an improved board layout concerning power gnd,
Monday, December 12, 2011
400 and 600 WATT AMPLIFIER WITH IRFP460 MOSFET CIRCUITS
Actrk 400/600 Watt
[read here...]
Two versions of a robust module capable of delivering high powwer for extended periods. The Actrk400 uses 6 n-channel Mosfets in the output stage to deliver around 400 watts into 4 ohms while the Actrk600 uses 12 n-channel Mosfets in the output stage to deliver power in excess of 600 watts into 4 ohms. One constructor has achieved almost 900 watts with the Actrk600 layout using 12 IRFP460 Mosfets.
Actrk 600W schematic
Tuesday, February 22, 2011
STK465 - 30 watt Stereo Power Amplifier Circuit
Completed STK465 is an amplifier of acoustic frequencies that offers qualitative output, using minimal exterior elements. Substantially he is one of big completed force. When it functions with tendency 56V then the tendency will be ± 28V as for the ground. With this recommended tendency of catering, the attributed force is 30 WRMS in charge 8 Ohm.
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| STK465 - 30 watt Stereo Power Amplifier Circuit |
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| STK465 Power Amplifier kit |
The STK465 Amplifier circuit is stereo and has two channels of amplifier in a nutshell. It is a formal designing that develops positively all the particularities completing. The amplifier can be supplied from a line of double polarity. Still it can function under a wide region of tendencies (±10V as ±28V). The requirements of current depend from the force of expense and it can they begin from 120mA up to 1A. It is very important the catering to be sufficiently unharnessing, so that is avoided imports of annoying noises.
Thursday, February 17, 2011
TDA 2616 - 1 2W Stereo Hi-Fi Amplifier Circuit
This is a circuit diagram of 2X12 W Hi-Fi Amplifier based on TDA 2616 IC which is the core part of this circuit. The TDA2616 is a stereo power amplifier IC. This amplifier IC finds applications in mains fed amplifier circuits such as stereo radio, tape and television. It has gain balance for both of the channels and hi-fi according to standards such as IEC 268 and DIN 45500. This IC has special inbuilt circuit for the suppression of noise signals at the inputs, during switch-on and switch-off. This avoids click sounds during power on and power off.
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| TDA 2616 - 1 2W Stereo Hi-Fi Amplifier Circuit |
Simple and less number of components make this circuit suitable for portable power amplifier circuits. A well regulated and filtered +/- 12 V dual power supply is used in this circuit to provide at least 2 A continuous current. The circuit can deliver a maximum output of 12 W power on 8 Ohm speaker for each channel at +/- 12 V dual supplies. This Hi-fi amplifier circuit can complement your audio system with ceiling speakers for home theater.
Wednesday, February 9, 2011
2N3055|MJ2955 Class B Amplifier
This simple Class B Amplifier, straightforward but rugged circuit, though intended for any high quality audio application and, above all, to complete the recently started series of articles forming the Modular Preamplifier Control Center, is also well suited to make a very good Guitar or Bass amplifier.
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| 2N3055|MJ2955 Class B Amplifier Circuit |
Using a mains transformer with a secondary winding rated at the common value of 25 + 25V (or 24 + 24V) and 100/120VA power, two amplifiers can be driven at 45W and 69W output power into 8 and 4 Ohms respectively, with very low distortion (less than 0.01% @ 1kHz and 20W into 8 Ohms).
List Componet of 2N3055|MJ2955 Class B Amplifier circuit
R1 : 18K D1,D2,D3,D4 : 1N4148
R2 : 3K9 Q1,Q2 : BC560C
R3,R6 : 1K Q3,Q4 : BC556
R4 : 2K2 Q5 : BC546
R5 : 15K Q6 : BD139
R7 : 22K Q7 : BD140
R8 : 330R Q8 : MJ2955
R9,R10 : 10R Q9 : 2N3055
R11,R12 : 47R
R13 : 10R
C1 : 1µF/63V
C2 : 470pF
C3 : 47µF/25V
C4 : 15pF
C5 : 220nF
C6 : 100nF
Sunday, January 16, 2011
22 Watt Car Subwoofer Amplifier
This Subwoofer circuit is intended to be connected to an existing car stereo amplifier, adding the often required extra "punch" to the music by driving a subwoofer. As very low frequencies are omnidirectional, a single amplifier is necessary to drive this dedicated loudspeaker.
The power amplifier used is a BTL TDA1516BQ IC made by Philips requiring a very low parts count and capable of delivering about 22W into a 4 Ohm load at the standard car battery voltage of 14.4V.
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| 22 Watt Car Subwoofer Amplifier Circuit |
The stereo signals coming from the line outputs of the car radio amplifier are mixed at the input and, after the Level Control, the signal enters the buffer IC1A and can be phase reversed by means of SW1. This control can be useful to allow the subwoofer to be in phase with the loudspeakers of the existing car radio. Then, a 12dB/octave variable frequency Low Pass filter built around IC1B, Q1 and related components follows, allowing to adjust precisely the low pass frequency from 70 to 150Hz.
Q2, R17 and C9 form a simple dc voltage stabilizer for the input and filter circuitry, useful to avoid positive rail interaction from the power amplifier to low level sections.
List Componet Of Car Subwoofer Amplifier
List Componet Of Car Subwoofer Amplifier
P1 : 10K Potentiometer
P2 : 22K Dual Potentiometer
R1,R4 : 1K 1/4W Resistors
R2,R3,R5,R6 : 10K 1/4W Resistors
R7,R8 : 100K 1/4W Resistors
R9,R10,R13 : 47K 1/4W Resistors
R11,R12 : 15K 1/4W Resistors
R14,R15,R17 : 47K 1/4W Resistors
R16 : 6K8 1/4W Resistor
R18 : 1K5 1/4W Resistor
C1,C2,C3,C6 : 4µ7/25V
C4,C5 : 68nF Polyester Capacitors
C7 : 33nF Polyester Capacitor
C8,C9 : 220µF/25V
C10 : 470nF Polyester Capacitor
C11 : 100nF Polyester Capacitor
C12 : 2200µF/25V
D1 : LED
Q1,Q2 : BC547 NPN Transistors
IC1 : TL072 Op-Amp
IC2 : TDA1516BQ
SW1 : DPDT toggle or slide Switch
SW2 : SPST toggle or slide Switch
SPKR : 4 Ohm Woofer or two 8 Ohm Woofers wired in parallel
Circuit From: www.redcircuits.com
18 Watt RMS Amplifier Using TIP41|42
This amplifier Circuit has output 18 Watt RMS into 8 Ohm and Frequency response 30Hz to 20KHz. It’s simple to build and you don’t need preamplifier. Besides that this Amplifier Circuit is also directly connected to Can some CD players, tuners and recorders tape. Do not exceed 23 + 23V supply. Of Q3 and Q4 must be mounted on heatsink. D1 must be in thermal contact with the Q1. Quiescent current (best measured with an Avo-meter in series with Q3 Emitter), is not critical. Adjust R3 to read a current Between 20 to 30 mA with no input signal.
List Component:
P1 : 2K Log. Potentiometer (Dual-gang for stereo) R1 : 1K 1/4W Resistor R2 : 4K7 1/4W Resistor R3 : 100R 1/4W Resistor R4 : 4K7 1/4W Resistor R5 : 82K 1/4W Resistor R6 : 10R 1/2W Resistor R7 : R22 4W Resistor (wirewound) R8 : 1K Trimmer Cermet (optional) C1 : 470nF Polyester Capacitor C2,C5 : 100µF/3V Tantalum bead Capacitors C3,C4 : 470µF/25V Electrolytic Capacitors C6 : 100nF Polyester Capacitor D1 : 1N4148 150mA Diode IC1 : TLE2141C Op-amp Q1 : BC182 NPN Transistor Q2 : BC212 PNP Transistor Q3 : TIP42A PNP Transistor Q4 : TIP41A NPN Transistor
IRF9530|IRF530 Simple MosFet Amplifier
This mosFet amplifier circuit 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.
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| IRF9530|IRF530 Simple MosFet Amplifier Circuit |
List Component
R1 : 2K2
R2 : 27K
R3,R4 : 2K2 1/2W Trimmers Cermet or Carbon (or 2K)
R5 : 100R
R6 : 1K
R7,R8 : 330R
C1 : 22µF/25V
C2 : 47pF
C3,C4 : 100µF/50V
C5 : 2200µF/ 50V
Q1 : BC550C
Q2 : IRF530
Q3 : IRF9530
Setting up the Power Amplifier:
- 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.
- Rotate the cursor of R4 fully towards Q1 Collector.
- Set the cursor of R3 to about the middle of its travel.
- Connect a suitable loudspeaker or a 8 Ohm 20W resistor to the amplifier output.
- Connect a Multimeter, set to measure about 50V fsd, across the positive end of C5 and the negative ground.
- Switch on the supply and rotate R3 very slowly in order to read about 23V on the Multimeter display.
- 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).
- Switch on the supply and rotate R4 very slowly until a reading of about 120mA is displayed.
- Check again the voltage at the positive end of C5 and readjust R3 if necessary.
- If R3 was readjusted, R4 will surely require some readjustment.
- Wait about 15 minutes, watch if the current is varying and readjust if necessary.
- Please note that R3 and R4 are very sensitive: very small movements will cause rather high voltage or current variations, so be careful.
- 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.
Circuit From: www.redcircuits.com
70 Watt Guitar Amplifier Using 2N30055/MJ2955 Transistor
The Guitar power amplifier circuit of this design adopts the still new but already successful 45 Watt Class B Amplifier Simplicity and ease of construction of this amplifier, combined with the complete absence of manual settings make it ideal for Guitar or Bass amplifier.
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| 70 Watt Guitar Amplifier Circuit |
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Preamplifier + Tone Control For Guitar Amplifier Circui |
The preamplifier features two almost identical three-transistor gain-blocks based on a complementary two-stage circuit with dynamic active load of the output transistor. A circuit topology early used in Revox tape recorders and audio preamplifiers with single rail supplies in the 18 - 24Vdc range.
In this preamp the gain blocks are powered by split supplies of ±24V with two advantages: a high output voltage of about 15V RMS allowing a very wide overload margin and the facility to easily derive the preamp power supply from the power amplifier main supply.
A three-band stacked-type tone control is implemented in the second stage but, unlike the more common passive controls, active controls are used here, allowing better signal to noise ratio and overload margin with no gain loss.
List Componet Of Guitar Amplifier
R1 : 8K R2 : 3K9 R3,R6 : 1K R4 : 2K2 R5 : 15K R7 : 22K R8 : 330R R9,R10 : 10R R11,R12 : 47R R13 : 10R C1 : 1µF/63V C2 : 470pF/63V C3 : 47µF/25V C4 : 15pF/63V C5 : 220nF/100V C6 : 100nF/63V D1,D2,D3,D4 : 1N4148 150mA Diodes Q1,Q2 : BC560C PNP Transistors Q3 : Q4BC556 PNP Transistors Q5 : BC546 NPN Transistor Q6 : BD139 NPN Transistor Q7 : BD140 PNP Transistor Q8 : MJ2955 PNP Transistor Q9 : 2N3055 NPN Transistor
List Componet Of Preamplifier
P1 : 10K Potentiometer P2,P3,P4 : 47K Potentiometers P5 : 10K Potentiometer R1,R2 : 33K R3 : 220K R4 : 390R R5,R14 : 3K9 R6,R15 : 8K2 R7,R16 : 12K R8,R11,R17,R20 : 560R R9,R18 : 5K6 R10,R19 : 100R R12 : 3K3 R13 : 18K C1,C12 : 220nF Polyester Capacitors C2,C13 : 100pF Ceramic Capacitors C3,C14 : 10pF Ceramic Capacitors C4,C15 : 47µF/25V Electrolytic Capacitors C5,C16 : 100µF/25V Electrolytic Capacitors C6,C7 : 10µF/25V Electrolytic Capacitors C8,C11 : 4n7 Polyester Capacitors C9 : 10nF Polyester Capacitor C10 : 47nF Polyester Capacitor Q1 : BC560C PNP Transistor Q2,Q3,Q5,Q6 : BC546 NPN Transistors Q4 : BC557 PNP Transistor
Circuit From: http://www.redcircuits.com/
Thursday, January 13, 2011
18W Guitar Amplifier Using Darlington Transistor
The aim of this design is to reproduce a Combo amplifier of the type very common in the 'sixties and the 'seventies of the past century. It is well suited as a guitar amplifier but it will do a good job with any kind of electronic musical instrument or microphone. 5W power output was a common feature of these widespread devices due to the general adoption of a class A single-tube output stage (see the Vox AC-4 model). Furthermore, nowadays we can do without the old-fashioned Vib-Trem feature frequently included in those designs. The present circuit can deliver 10W of output power when driving an 8 Ohm load, or about 18W @ 4 Ohm. It also features a two-FET preamplifier, two inputs with different sensitivity, a treble-cut control and an optional switch allowing overdrive or powerful treble-enhancement.
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| 18W Guitar Amplifier Using Darlington Transistor Circuit |
- SW1 and related capacitors C4 & C5 are optional.
- When SW1 slider is connected to C5 the overdrive feature is enabled.
- When SW1 slider is connected to C4 the treble-enhancer is enabled.
- C4 value can be varied from 100nF to 470nF to suit your treble-enhancement needs.
- To set quiescent current, remove temporarily the Fuse F1 and insert the probes of an Avo-meter in the two leads of the fuse holder.
- Set the volume control to the minimum and Trimmer R9 to its minimum resistance.
- Power-on the circuit and adjust R9 to read a current drawing of about 25 to 30mA.
- Wait about 15 minutes, watch if the current is varying and readjust if necessary.
List Component:
P1 : 4K7 Linear Potentiometer
P2 : 10K Log. Potentiometer
R1,R2 : 68K 1/4W Resistors
R3 : 220K 1/4W Resistor
R4,R6,R11 : 4K7 1/4W Resistors
R5 : 27K 1/4W Resistor
R7 : 1K 1/4W Resistor
R8 : 3K3 1/2W Resistor
R9 : 2K 1/2W Trimmer Cermet
R10 : 470R 1/4W Resistor
R12 : 1K5 1/4W Resistor
R13 : 470K 1/4W Resistor
R14 : 33K 1/4W Resistor
C1 : 100pF Ceramic Capacitor
C2 : 100nF Polyester Capacitor
C3 : 470µF Electrolytic Capacitor
C4 : 220nF Polyester Capacitor (Optional, see Notes)
C5 : 47µF/25V Electrolytic Capacitor (Optional, see Notes)
C6 : 1µF/63V Polyester Capacitor
C7,C8,C9,C10 : 47µF/25V Electrolytic Capacitors
C11 : 47pF/63V Ceramic Capacitor
C12 : 1000µF/35V Electrolytic Capacitor
C13 : 2200µF/35V Electrolytic Capacitor
D1 : 5mm. Red LED
D2,D3 : 1N4004/400V 1A Diodes
Q1,Q2 : 2N3819 General-purpose N-Channel FETs
Q3 : BC182 NPN Transistor
Q4 : BD135 NPN Transistor (See Notes)
Q5 : BDX53A NPN Darlington Transistor
Q6 : BDX54A PNP Darlington Transistor
SW1 : pole 3 ways rotary switch
SW2 : SPST Mains switch
F1 : 1.6A Fuse with socket
T1 : 220V Primary, 48V Center-tapped Secondary 20 to 30VA Mains transformer
Wednesday, November 24, 2010
200 WATT AUDIO AMPLIFIER
Load Resistance : 8ohms
Input impedance : 55K
Maximum supply voltage : (+95v)-0-(-95v)
Recommended supply voltage : (+66v)-0-(-66v)
This complete high quality, low noise mono audio power amplifier is based around the Hybrid Integrated Circuit STK4050 manufactured by Sanyo. The circuit incorporates volume and has a maximum music output power of 200W. The circuit incorporates an on board power supply; therefore, only centre tapped transformer is required to power the circuit. I t has very good quality sound. U can use it with your Home Theatre your PC & etc... You can also use it as Subwoofer Amplifier. It is a compact package for THIN-TYPE Audio sets. Easy Heat sink design to disperse heat generated in THIN-TYPE audio sets. Constant-Current circuit to Reduce supply switch-ON and switch-OFF shock noise. External supply switch-On and switch-OFF shock noise muting, Load short-circuit protection, thermal shutdown and other circuits can be tailored-designed.
Thursday, July 29, 2010
100W Audio Amplifier
General Description
This is an exceptionally well designed amplifier, with a lot of power reserve, high fidelity, low distortion, good S/N ratio, high sensitivity, low consumption and full protection. Having all these almost ideal characteristics this amplifier is likely to become the basic building block of your future high fidelity system, or it can also become the element that will upgrade your existing system.
[read here...]
How it Works
The circuit works from a symmetrical ñ 40 VDC power supply and draws a maximum current of 2.6 A. The input circuit of the amplifier is a differential amplifier built around Q4 and Q5 that employ DC feedback thus preventing any DC voltage from appearing across the speaker with the usual destructive results. Q11 acts as a current source and ensures that the input stage draws a constant current of 1 mA. The signal which appears as a voltage drop across the resistor connected in series with the collector of Q4 is used to drive the DARLINGTON pair Q3, Q2 which together with the constant current source of 7 mA that is Q10, form the driver stage. This stage operates in class A and is driving the complementary output stage Q1, Q9. The transistor Q7 is used to balance the circuit at different temperatures and must be mounted on the heatsink between the out put transistors. The feedback loop which consists of R8, R9, C2, C3 provides AC stability to the circuit. The circuit also incorporates a protection stage that makes it virtually indestructible. This protection circuit is built around Q6, Q8. If for whatever reason the output remains connected on one supply rail and the common the output is also protected from high DC voltages that could burn the speakers. The supply rails should be protected by 2 A fuses for the 8 ohm version and 3 A for the 4 ohm.
Technical Specifications - Characteristics
Output power (f=1 KHz, d=0.5 %): 100 W in 8 ohm
Supply voltage: ................ 40 V
Quiescent current: ............. 50 mA
Maximum current: ............... 2.6 A
Sensitivity: . 600 mV
Frequency response: ............ 10-35000 Hz (-1 dB)
Distortion HD: ................. 0.01 %
Intermodulation dist.: ......... 0.02 %
Signal/noise: 83 dBConstruction
PLEASE READ THIS BEFORE YOU START CONSTRUCTION
To cater for those who wish to use 4 ohm speakers with this amplifier the Kit includes the necessary components for both versions. The components that differ are R3,4,17 and 23. If you build the 8 ohm version then you must also include in the circuit R28 and D7, D8 which are not used in the 4 ohm version. As you see all the components are already marked on the component side of the p.c. board. The construction is made this way much simpler. Start the construction from the pins and the jumper connections, continue with the resistors and the capacitors and last solder in place the semiconductors. Check each resistor before soldering it, to see if its colours match those in the component list. Be careful with the electrolytic capacitors because their polarity should be respected. The polarity of those capacitors is marked on their bodies and on the component side of the p.c. board. NOTE: On the p.c. board next to R2, R16 are marked two other resistors which do not appear in the circuit diagram but are included in the components. They are of 1 ohm 2 W (brown, black, gold) and must be included in the circuit. Take care when you are soldering the semiconductors because if you overheat them they can be damaged. The output transistors should be mounted on the heatsink that is included in the kit. Take care not to short circuit them with the heatsink and we recommend that you use some HTC between the transistor body and the sink in order to improve heat dissipation. Follow the diagram for the mounting of the power transistors as it shows clearly how to insert the insulators and the screws. Q7 should be made to touch the heatsink and is a good idea to use a bit of HTC between its casing and the surface of the heatsink. When you finish the construction of your project clean the board thoroughly with a solvent to remove all flux residues and make a careful visual inspection to make sure there are no mistakes, components missing and short circuits across adjacent tracks on the board. If everything is OK you can make the following connections: Input: 3 (signal), 5 (common) Output: 7 (signal), 6 (common) Supply: 1 (-40 VDC), 2 (+40 VDC) 5 (0 VDC)
Connect a milliammeter in series with the power supply, short the input of the amplifier, turn the power ON and adjust the trimmer P1 so that the quiescent current is about 50 mA. When you finish this adjustment remove the shunt from the input and connect the output of a preamplifier to it. Connect the pre amplifier to a suitable source and turn everything ON. The signal should be heard from the speakers clear and undistorted. First of all let us consider a few basics in building electronic circuits on a printed circuit board. The board is made of a thin insulating
material clad with a thin layer of conductive copper that is shaped in such a way as to form the necessary conductors between the various components of the circuit. The use of a properly designed printed circuit board is very desirable as it speeds construction up considerably and reduces the possibility of making errors. Smart Kit boards also come pre-drilled and with the outline of the components and their identification printed on the component side to make construction easier. To protect the board during storage from oxidation and assure it gets to you in perfect condition the copper is tinned during manufacturing and covered with a special varnish that protects it from getting oxidised and makes soldering easier. Soldering the components to the board is the only way to build your circuit and from the way you do it depends greatly your success or failure. This work is not very difficult and if you stick to a few rules you should have no problems. The soldering iron that you use must be light and its power should not exceed the 25 Watts. The tip should be fine and must be kept clean at all times. For this purpose come very handy specially made sponges that are kept wet and from time to time you can wipe the hot tip on them to remove all the residues that tend to accumulate on it.
DO NOT file or sandpaper a dirty or worn out tip. If the tip cannot be cleaned, replace it. There are many different types of solder in the market and you should choose a good quality one that contains the necessary flux in its core, to assure a perfect joint every time.
DO NOT use soldering flux apart from that which is already included in your solder. Too much flux can cause many problems and is one of the main causes of circuit malfunction. If nevertheless you have to use extra flux, as it is the case when you have to tin copper wires, clean it very thoroughly after you finish your work. In order to solder a component correctly you should do the following:
- Clean the component leads with a small piece of emery paper. - Bend them at the correct distance from the component body and insert the component in its place on the board.
- You may find sometimes a component with heavier gauge leads than usual, that are too thick to enter in the holes of the p.c. board. In this case use a mini drill to enlarge the holes slightly. Do not make the holes too large as this is going to make soldering difficult afterwards.
- Take the hot iron and place its tip on the component lead while holding the end of the solder wire at the point where the lead emerges from the board. The iron tip must touch the lead slightly above the p.c. board.
- When the solder starts to melt and flow, wait till it covers evenly the area around the hole and the flux boils and gets out from underneath the solder. The whole operation should not take more than 5 seconds. Remove the iron and leave the solder to cool naturally without blowing on it or moving the component. If everything was done properly the surface of the joint must have a bright metallic finish and its edges should be smoothly ended on the component lead and the board track. If the solder looks dull, cracked, or has the shape of a blob then you have made a dry joint and you should remove the solder (with a pump, or a solder wick) and redo it.
- Take care not to overheat the tracks as it is very easy to lift them from the board and break them.
- When you are soldering a sensitive component it is good practice to hold the lead from the component side of the board with a pair of long-nose pliers to divert any heat that could possibly damage the component.
- Make sure that you do not use more solder than it is necessary as you are running the risk of short-circuiting adjacent tracks on the board, especially if they are very close together.
- When you finish your work cut off the excess of the component leads and clean the board thoroughly with a suitable solvent to remove all flux residues that still remain on it.
If it does not work
Check your work for possible dry joints, bridges across adjacent tracks or soldering flux residues that usually cause problems. Check again all the external connections to and from the circuit to see if there is a mistake there.
- See that there are no components missing or inserted in the wrong places.
- Make sure that all the polarised components have been soldered the right way round. - Make sure the supply has the correct voltage and is connected the right way round to your circuit.
- Check your project for faulty or damaged components. If everything checks and your project still fails to work, please contact your retailer and the Smart Kit Service will repair it for you.
L1 : 10 turns with wire 0,5mm turned on a restistor of 1W
If you use a 4Ohm speaker you will place R3,4,17,23 at the board.
If you use a 8Ohm speaker you will place D7 D8 and R28.
For R2 and R16 if you don't find a 0,47Ohm place two of 1 Ohm parallel.
R16 must be 0,47Ohm...the 1Ohm must be a typographical error, take care of this, i haven't tested it.
Sunday, June 27, 2010
Amplifier 250-500W with transistors MJ15003.
GENERAL DISCRIPTION :The circuit is based around (TL 071) manufactured by NATIONAL semiconductors (MJ15003) by ON semiconductors It is a high fidelity audio power amplifier. Designed for demanding consumer and pro-audio applications. You can also use this circuit with AV receivers, Audiophile power amps, Pro Audio High voltage industrial applications etc Amplifier output power maybe scaled by changing the supply voltage and number of output devices.
General Specifications
Rated Power Output
(20Hz to 20kHz Continuous Average Sine Wave)
250 watts into 8 ohms
500 watts into 4 ohms
Power Bandwidth
(250 watts into 8 ohms)
20Hz to 40kHz (0dB to -3dB)
Frequency Response
1 watt into 8 ohms
20Hz to 100kHz (0dB to -1.0 dB)
250 watts into 8 ohms
20Hz to 20kHz (Flat)
Input Sensitivity
+3 dBV
(1.4V RMS produces an output of 350 watts into 8 ohms)
Input Impedance
33K ohms, Unbalanced
Rise Time
2.0 microSeconds
Total Harmonic Distortion (THD)
Full Power(250 watts into 8 ohms)
Less than 0.007 % THD @ 1kHz
Less than 0.08 % THD @ 20Hz to 20kHz
Half Power (125 watts into 8 ohms)
Less than 0.003 % THD @ 1kHz
Less than 0.03 % THD @ 20Hz to 20kHz
10 watts into 8 ohms
Less than 0.003 % THD @ 1kHz
Less than 0.01 % THD @ 20Hz to 20kHz
Friday, May 7, 2010
TDA1562Q . . . 50W from a 12 V battery (Elektor 2/2000)
The integrated output amplifier described in this article consists of little more than one integrated circuit. It is intended especially for use in motor vehicles and other batteryoperated applications. Although it appears simple and hardly worth looking at, the amplifier can produce an appreciable audio power output.
technical data
Properties
High power output through Class-H operation
Low power dissipation during reproduction of music signals
Proof against short-circuits
Protection against excessive temperatures
Standby switch
No power-on or power-off clicks
Visible error indication
Measurement results (at Ub=14.4 V)
Supply voltage 8–18 V
Sensitivity 760 mV r.m.s.
Input impedance 70 kΩ
Power output 54 W r.m.s. into 4 Ω (f=1 kHz; THD+N=1%)
Harmonic distortion (THD+N) at 1 W into 4 Ω: 0.046% (1 kHz)
0.29% (20 kHz)
at 35 W into 4 Ω: 0.12% (1 kHz)
0.7% (20 kHz)
Signal-to-noise ratio (with 1 W into 4 Ω) 88 dBA
Power bandwidth 7.5 Hz – 185 kHz (at 25 W into 4 Ω)
Quiescent current about 135 mA (‘on’)
COMPONENTS LISTResistors:
R1 = 1MΩ
R2 = 4kΩ7
R3 = 1kΩ
R4 = 100kΩ
Capacitors:
C1,C2 = 470nF
C3,C4 = 10μF 63V radial
C5,C6,C8 = 4700μF 25V radial
(18mm max. dia., raster 7.5 mm)
C7 = 100nF, raster 5 mm
Semiconductors:
D1 = high-efficiency-LED
IC1 = TDA1562Q (Philips)
Miscellaneous:
S1 = single-pole on/off switch
Four spade connectors, PCB mount
Heatsink for IC1 (Rth<2.5>
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