L200 current source mosfet matching circuit. Use 12 volts for IC1 (STMicroelectronics L200) Vsupply.
Digital voltmeter to three decimal places at 2 to 6 volts recommended.
Current set to 500mA (higher current cause device heating).
Mount DUTs on common heatsink as per picture.
Allow reading to stabilize (about 10 seconds) before noting value.
Once close matches have been ascertained retest those matches to get best fits.
This is for a Older model ROCKFORD FOSGATE PUNCH 75 MOSFET AMPLIFIER. This holds power unlike the newer models. The Punch 75 is 37.5 watts RMS continuous power per channel into four phms with less than 05% total hormonic distortion from 20-20000 HZ.
SPECS| AN18 Power MOSFET Gate Driver Circuits using High Current Super-b Transistors: 6A Pulse Rated SOT23 Transistors for High Frequency MOSFET Interfacing: Zetec Semiconductors A description of the MOSFET converter circuits' requirement for a high current buffer stage, a suggested range of Zetex high current capable, fast switching transistors, and circuit examples. |
25 Watt MOSFET Amplifier: High Quality simple unit. No need for a Preamplifier
The Hx350 is the epitome of power. With 10 pieces of IRFP240/9240, it is capable of delivering an astounding 600Watts/RMS into 4 W (before clip).
But the Hx350 is more than raw power. It's about the quality of Watts. It has none of the edginess and harshness that proamps are notorious for. When used in the home, the Hx350 is ideally suited for high powered subwoofers or power hungry main speakers.
The Hx350 is the only amplifier in AmpsLab with our Loudspeaker Protection Circuitry (DCpro Kit) on board.
Read more source : http://www.ampslab.com/hx350.htm
The Lm60 uses a pair of highly acclaimed Hitachi Lateral Mosfets 2SK1058 & 2SJ162 for the current stage.
The new generation of Switching Mosfets, IRFP240/9240, are making sweeping changes in power amplification.Simple Class A Amplifier
A 10-W Design giving subjectively better results than class B transistor amplifiers
When your monster (or not so monster) power amplifier is switched on, the initial current drawn from the mains is many times that even at full power. There are two main reasons for this, as follows ...
A 10-W Design giving subjectively better results than class B transistor amplifiers
by J. L. Linsley Hood, M.I.E.E.
circuit TDA2020 power amp 80W hi-fi
PCB Pre MIC (microphone preamplifier) 2 CH by IC NE5532 or LF353
circuit 5 Transister (C945) tone control mono.
PCB 4 Transister (C945) tone control mono.
Circuit Pre MIC - 3 Transister (C945) mono
PCB Pre MIC - 3 Transister (C945) mono
PCB Pre MIC - 3 Transister (C945) mono
Circuit : Sergio Garcํa de Alba Garcin from Guadalajara, Mexico
Design: Graham Maynard
Source : http://www.mitedu.freeserve.co.uk/Circuits/Audio/t-ctrl.htm
This is a very simple, low cost, Hi-Fi quality power amplifier. You can build it 5 ways, like it�s shown in the table (from 20 W to 80 W RMS).
Some comments:
- The first thing that you must do, is to measure the end transistors (T3 and T4) amplifying coefficient, the hfe or β. If their disagreement is bigger than 30 %, the amplifier would not give a clear sound. I used MJ3001 and MJ2501 transistors, and this disagreement was around 5%.
- Before the first �turning on� you must short circuit the inputs of the amp, and put a mA-meter on the output, than turn the amplifier on, and tune the R13 pot, to decrease the DC current on the output, to some uA-s, or in a lucky situation to zero. I was able to decrease it to 10 uA.
Simple and low cost. The optimal supply voltage is around 50V, but this amp work from 30 to 60V. The maximal input voltage is around 0.8 - 1V. As you can see, in this design the components have a big tolerance, so you can build it almost of the components, which you find at home. The and transistors can be any NPN type power transistor, but do not use Darlington types... The output power is around 60W.
Some comments:
- capacitor C1 regulates the low frequencies (bass), as the capacitance grows, the low frequncies are getting louder.
- capacitor C2 regulates the higher frequencies (treble), as the capacitance grows, the higher frequencies are getting quiter.
- this is a class B amplifier, this means, that a current must flow through the end transistors, even if there is no signal on the input. This current can be regulated with the 500Ω trimmer resistor. As this current incrases, the sound of the amplifier gets better, but the end transistors are more heating. But if this current decrases, the transistors are not heating so much, but the sound gets worse...
copy from : http://www.electronics-lab.com/projects/audio/042/index.html
thank you.
| -- High Quality very simple unit |
| -- No need for a preamplifier |
Circuit diagram:
Amplifier parts:
| P1 = 22K | 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 | 1/2W Trimmer Cermet (optional) |
| C1 = 470nF | 63V Polyester Capacitor |
| C2,C5 = 100΅F | 3V Tantalum bead Capacitors |
| C3,C4 = 470΅F | 25V Electrolytic Capacitors |
| C6 = 100nF | 63V Polyester Capacitor |
| D1 = 1N4148 | 75V 150mA Diode |
| IC1 = TLE2141C | Low noise,high voltage,high slew-rate Op-amp |
| Q1 = BC182 | 50V 100mA NPN Transistor |
| Q2 = BC212 | 50V 100mA PNP Transistor |
| Q3 = TIP42A | 60V 6A PNP Transistor |
| Q4 = TIP41A | 60V 6A NPN Transistor |
| J1 | RCA audio input socket |
Power supply parts:
| R9 = 2K2 | 1/4W Resistor |
| C7,C8 = 4700΅F | 25V Electrolytic Capacitors |
| D2 | 100V 4A Diode bridge |
| D3 | 5mm. Red LED |
| T1 | 220V Primary, 15 + 15V Secondary 50VA Mains transformer |
| PL1 | Male Mains plug |
| SW1 | SPST Mains switch |
Notes:
Can be directly connected to CD players, tuners and tape recorders.
Don't exceed 23 + 23V supply.
Q3 and Q4 must be mounted on heatsink.
D1 must be in thermal contact with 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.
To facilitate current setting add R8 (optional).
A correct grounding is very important to eliminate hum and ground loops. Connect in the same point the ground sides of J1, P1, C2, C3 &C4. Connect C6 at the output ground.
Then connect separately the input and output grounds at the power supply ground.