Saturday 13 August 2011

100Watt Bipolar Power Amplifier Circuit with BD139-BD140


This is a basic 100 watt power amplifier designed to be (relatively) easy to build at a reasonable price. It has a better performance (read: musical quality) than the standard STK module amps that are used in almost every mass market stereo receiver manufactured today. When I originally built this thing, it was because I needed a 100 WPC amp and do not want any money. So I designed around parts I had in the store.
The design is actually a standard format, and I’m sure there are commercial entities that are similar. To my knowlwdge, it is not an exact copy of a commercial entity, nor am I aware of any patents on topology. For experienced builders: I am aware that many improvements and adjustments can be made, but the idea was to keep it simple and must do-able by anyone who is a circuit, and has not the patience to do a sloppy job.
If friend want Bipolar Transistor power amplifier circuit. , In model HIFI OCL 100W RMS. I think this track should be an interesting choice, this circuit is the use of the key transistor BD317 and BD318 unless transistor number BD139, BD140, BC556 too easy then try to buy when the 35V power source with only then build is not difficult for other details as the result of a few See Circuit.  Input stage is a BC556 transistor, which most of the open loop gain, and on the serene DC voltage stabilizes. This feeds a level shift stage where the voltage swing to (-) track references. The Transconductance stage is a Darlington, improve frerqency high linearity. The BD317, 318 on a rather large collector-base capacity is dependent on voltage. The BD319 presents this low-z and has a C (ob) of only a few of PF, which is effectively swamped by the pole-splitting 220pF cap. The scene is supplied by BC546 active load (current), which is approximately 20 mA. The current, until the BC556 is limited to about 70 mA in the worst cases.

Audio Level Meter with 8 LEDs Indicator

This audio level meter required 2 pieces of LM324 for each channel. Every single LM324 contain 4 op-amps, then you need 2 pieces of LM324 to cover 8 LEDs. And need 4 piece of LM324 for 16 LEDs (for stereo channel)
Here the schematic:
Audio Level Meter with 8 LEDs Indicator circuit diagram

Amplifier Power Indicator

This is one of many audio level indicator circuit. The different is that this circuit should be connected tho the output of amplifier while the other indicators connected before amplifier module. This circuit will show the real audio output by LED indicator level.

Amplifier Power Indicator circuit diagram

R1_____________220R  1/2W Resistor
R2,R5,R6,R8____100R 1/4W Resistors
R10,R12,R14____100R 1/4W Resistors
R3_____________220R 1/4W Resistor
R4,R7__________330R 1/2W Resistors
R9_____________560R 1/2W Resistor
R11____________820R 1/2W Resistor
R13______________1K2 1/2W Resistor

D1___________1N4004 400V 1A Diode
D2,D4,D6__BZX79C2V7 2.7V 500mW Zener Diodes
D3,D5,D7,D8,D9,D10 Red LEDs (Any dimension and shape) (See Notes)

Notes:

  • The output power indicated by each LED must be doubled when 4 Ohms loads are driven.
  • The circuit can be adapted to suit less powerful amplifiers by reducing the number of LEDs and related voltage dividers.
  • LEDs of any dimension can be used, but rectangular shaped devices will be more suitable to be compacted in bars or columns.
  • For a stereo amplifier, two identical circuits are required.

10 LEDs Audio VU Meter circuit with LM3915


This is very nice VU meter circuit for your own audio system project.

10 LEDs Audio VU Meter circuit

Build based IC LM3915, this circuit will indicate the power audio level of your audio system. This circuit is very simple, inexpensive and easy to build.

Visit this page for complete explanation. Follow the instruction and use the proper power supply for this circuit.

Wednesday 10 August 2011

500W 27Mhz RF Amplifier Circuit


500W 27Mhz RF Amplifier Circuit diagram

Parts List:

C1,C3 = 75-380 pF mica trimmer, ARCO 465
C4-C8 = .01 uF 1 kV disc ceramic
C9,C10 = .1 uF 500V disc ceramic
L1 = 6 uH. 25t #24 ga.enam. 0.5" dia.
L2 = 210 nH. 4t #8 ga. .75" id, 1" long
L4 = 2t #20 PTFE on .5" ferrite bead m=850
Q1 = APT ARF448A
R1 = 25W 5W non-inductive
T1 = Pri: 4t #20 PTFE, Sec: 1t brass tube on 2 hole balun bead. Fair-Rite #2843010302 m=850


High voltage MOSFETs are now available that combine the best practices from the RF world with the economy of the switchmode devices and packaging. They are available in mirror image pairs and the heat spreader of the plastic TO-247 package is connected to the source.

Download the aplication note for this circuit 500W 27Mhz RF Amplifier HERE

AM RF Amplifier Circuit for External Antenna


AM RF Amplifier Circuit for External Antenna

This is an AM RF Amplifier Circuit for External Antenna which built using RCA 40468A FET. The detailed explanation and recomendation about this circuit, go tothis page.

60W Linear RF Amplifier Circuit


electronic circuit diagram


The 60 Watt linear rf amplifier is easy all solid state circuit applying power mosfet IRF840. The IRF series of power transistors are provided in a number of voltage and power ratings. A single IRF840 can carry out maximum power output of 125 watts. Because these transistors are applied in inverters and smps, they're simply presented for about Rs: 20/-.

The IRF linear amplifier could be connected to the out put of well-known VWN-QRP to obtain an output of 60 Watts. The circuit draws 700 ma at 60 Volt Vcc. Great heat sink is actually a ought to for the power transistor.

Alignment of the circuit is quite effortless. Connect a dummy load to the out put of the circuit. It is possible to use some modest bulb like 24V 6Watts as the dummy load. I've even utilized 230V 60Watts bulb as dummy load with my IRF840 power amplifier working at 120Volts. Adjust the 10K preset to obtain about 100 ma Drain current. I applied gate voltage of 0.8V with my linear amplifier. A heigh gate voltage can make the power transistor get distroyed by self oscillation. So gate voltage ought to be below 2V and fixing at 1V is going to be secure.

Bifalar transformaer T1 is wound with 8 turns 26SWG on 1.4 x 1 balun core. The coil on the drain of IRF is 3 turns 20 SWG wound on 4 number of T13.9 torroids (two torroids are stacked to form a balun core). The RFC at the Vcc line is 20 Turns 20 SWG wound on T20 torroid.

60W Linear RF Amplifier circuit source:
http://www.flashwebhost.com/circuit/60_watts_rf_amplifier.php