Showing posts with label watt. Show all posts
Showing posts with label watt. Show all posts
Monday, May 13, 2013
25 Watt Audio Amplifier Circuit
This is a 25 Watt basic power amp that was designed to be (relatively) easy to build at a reasonable cost. It has better performance than the standard STK module amps that are used in practically every mass market stereo receiver manufactured today. When I originally built this thing, it was because I needed a 25 Watt PC amp and did not want to spend any money. So I designed around parts I had in the shop. Parts:
R1 = 47K R2 = 4K7 R3 = 1K5 R4 = 47K R5 = 390R R6 = 470R R7 = 33K R8 = 150K R9 = 15K R10 = 27R R11 = 500R-1/2W R12 = 10R R13 = 10R R14 = 220R R15 = 220R R16 = 10R R17 = 8.2R-2W R18 = 22R-4W(wirewound) C1 = 470nF-63V C2 = 330pF-63V C3 = 470µF-63V C4 = 100nF-63V C5 = 470µF-63V C6 = 100nF-63V C7 = 100µF-25V C8 = 100nF-63V C9 = 10pF-63V C10 = 1µF-63V C11 = 100nF-63V Q1 = BC560C Q2 = BC560C Q3 = BC560C Q4 = BC560C Q5 = BC560C Q6 = BD140 Q7 = BD139 Q8 = IRF530 Q9 = IRF9530
Parts:
R1 = 3K3-1/2W C1 = 10nF-1000V C2 = 4700µF-50V C3 = 4700µF-50V C4 = 100nF-63V C5 = 100nF-63V D1 = 200V 8A Diode bridge D2 = 5mm. Red LED F2 = 3.15A Fuses with sockets F2 = 3.15A Fuses with sockets T1 = 220V Primary, 25 + 25V Secondary 120VA Mains transformer PL1 = Male Mains plug SW1 = SPST Mains switch
Notes:
* Can be directly connected to CD players, tuners and tape recorders. Simply add a 10K Log potentiometer (dual gang for stereo) and a switch to cope with the various sources you need. * Q6 & Q7 must have a small U-shaped heatsink. * Q8 & Q9 must be mounted on heatsink. * Adjust R11 to set quiescent current at 100mA (best measured with an Avo-meter connected in series to Q8 Drain) with no input signal. * A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of R1, R4, R9, C3 to C8. Connect C11 to output ground. Then connect separately the input and output grounds to power supply ground. * An earlier prototype of this amplifier was recently inspected and tested again after 15 years of use. Results, comments and pictures are shown here.
Tuesday, April 9, 2013
Regulated 24 Watt Broad Spectrum LED
This project involves constructing an energy efficient broad spectrum LED lamp system. The lamp is useful for indoor reflective room lighting. It has a broad color spectrum that more closely approximates the light of the sun when compared to fluorescent bulbs and white-only LEDs. The light level is regulated and the light that is produced does not flicker. The six differently colored LED stars, made by LedEngin, Inc., are rated at 5 watts (nominal). The LED array and associated current regulator consume 1 amp at 24VDC (24 Watts). NEVER stare directly at this lamp when it is running at full operating power, it is DANGEROUSLY BRIGHT.
Regulated 24 Watt Broad Spectrum LED Circuit diagram :
With the LEDs shown, the combined color of the lamp has a pinkish white hue. The 5 Watt ratings of the LEDs are not precise, the white, blue and green LEDs consume about 4W and the lower voltage red, orange and deep red LEDs consume about 3W. The current regulator keeps the LED brightness constant and insures that the LED series string never draws more than 1 amp of current.
The project has also been coined "Bold as LED" in reference to the Jimi Hendrix song "Bold as Love" which has the lyric: "My yellow in this case is not so mellow"
Specifications:
- Nominal operating power: 24 Watts (24V DC at 1 Amp)
- LED power consumption above regulation point: 18.6 Watts
- Maximum operating voltage: 28V DC
- Minimum voltage for regulated light: 23V DC
- Leds produce light down to 11V
- Deep Red LED voltage: 2.55V
- Red LED voltage: 2.37V
- Amber LED voltage: 2.60V
- Green LED voltage: 3.92V
- Blue LED voltage: 3.56V
- White LED voltage: 3.7V
- Voltage across regulator when current becomes regulated: 4.2V
Theory:
The lamp is wired as a current loop which includes the power supply, the LED series string and the 1 amp current regulator circuit. The LM317K and 1.2 ohm 5 Watt resistor act as a current regulator that limits the loop current to 1 Amp. During regulation, there will always be 1.2V across the 1.2 ohm resistor. The current regulator insures that the LEDs always run at their maximum brightness, but not so bright that they burn out. A 100uF electrolytic capacitor bypasses the DC power input to the device and a 100nF monoblock capacitor bypasses the LM317K input.
Construction:
The LEDs and current regulator circuit were mounted on a 3" x 8" chunk of 1/8" aluminum stock. The LM317K regulator and LED heat sinks were bolted to the chassis directly, heat sink grease was used on the regulator, the heat sinks and the six LEDs. Connecting the LM317K directly to the aluminum plate makes the plate electrically hot at 1.2V, the plate should not be allowed to come into contact with any live conductors. By using a few more parts, the LM317 can be mounted with an insulator and plastic shoulder washers for electrical isolation from the mounting plate.
The LEDs come mounted on their own small star-shaped aluminum substrates, these were attached to the aluminum plate using two 7/16" 4-40 screws and nuts per LED. A drop of silicone heat sink grease should be applied to the center of each LED star when it is mounted to the plate for heat conduction. It is important to use insulating plastic washers on the top side of the LED stars to prevent electrical contact with head of the screw. The LED stars were soldered together using short pieces of #20 tinned wire after being mounted on the plate. It is necessary to use a fair amount of heat to solder the contacts, a 200/240W soldering gun did the job. Be very careful not to melt the lenses on the LEDs, the LEDs cost around $10 each. The positive and negative leads of the LED series string were connected back to the current reglator circuitry using #20 wire covered with teflon insulation.
The initial mechanical arrangement did not pass the "rule of thumb" test, which says that if a semiconductor is too hot to hold your thumb on, it will not live a long life. Two large aluminum heat sinks were bolted to the back of the aluminum plate and seem to be sufficient to keep the lamp operating at a reasonable temperature. The LED array produces more heat than the LM317K.
Use:
Connect this circuit to a 24VDC power supply or other power source such as a solar-charged lead acid battery. Be sure to observe the correct polarity. Look away from the LEDs and apply power. Again, do not stare directly at the LEDs, they are bright enough to harm your vision. A switch-mode power supply rated at 24VDC and 1 Amp or more is probably the most energy-efficient way to power this device from line power.
Parts:
- 1x LM317K T03 case 1.5A adjustable voltage regulator
- 1x 1.2 ohm 5W resistor (or 2x 2.4 ohm 2W resistors in parallel)
- 1x 100uF 35V or higher electrolytic capacitor
- 1x 100nF 35V or higher monolythic capacitor
- 1x LedEngin LZ1-10R205 deep red 5W LED
- 1x LedEngin LZ1-10R105 red 5W LED
- 1x LedEngin LZ1-10A105 amber 5W LED
- 1x LedEngin LZ1-10G105 green 5W LED
- 1x LedEngin LZ1-10B105 blue 5W LED
- 1x LedEngin LZ1-10CW05 cool white 5W LED
- Miscellaneous wire, solder lugs, termination strips and hardware,
- Large aluminum mounting plate, heat sinks if necessary.
Monday, April 1, 2013
Class T 30 watt amplifier Dayton
Dayton Audios DTA-1 has the hub of a serious player into a really portable package. A group-T imperfection lets the DTA-1 crop imaging, dynamics, and sound quality so as to rivals tube amps. Up to 15 watts for every channel is on tap to endorse bookshelf speakers.
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| Dayton Audio DTA-1 Class T Digital AC/DC Amplifier 15 |
- Palm-size course group-T 30 watt amplifier
- Battery otherwise AC powered-power supply integrated-instead of picture perfect portability
- 88% Amp efficiency for longer battery life
- senior sound quality
Saturday, March 30, 2013
10 Watt Stereo Amplifier Circuit Using TDA2009A
This is a design circuit for amplifier. This amplifier circuit has a power of 10 watts. This amplifier circuit is very suitable to apply to your car audio. This amplifier is using IC TDA2009A, as amplifier power. To avoid excessive heat in the IC using some heat sink compound between the heat sink & the IC. C1 & C2 is the input coupling capacitor and blocks DC, as well as C10 & C11 which is the output capacitor Kopel, and C6 & C7 which blocks the DC from the feedback loop. R1/R2 (and R3/R4) set the level of feedback. This is the figure of the circuit.
Get together with 1 (R1/R2) = 68 or 37 dB. C8/R5 (and C9/R6) provides high frequency stability where loudspeaker inductive reactance load can become excessive. C4 and C5 provide power decoupling or filtering. Absolute maximum supply voltage is 28V for the amplifier.
Wednesday, March 27, 2013
4 X 15 Watt Mini Power Amplifier
A lot of electronic circuits in the domain of audio amplifiers are already been published here. This circuit is a little different because it is a four channel amplifier. Each channel of this amplifier can deliver an output of 15Watts into a 4 ohm speaker. The amplifier can be operated from a single 12V DC supply and this makes it possible to use this amplifier in car audio applications too.
Circuit diagram :
4 X 15 Watt Mini Power Amplifier
The circuit is based on the 15W BTL X 2 channel audio power amplifier IC TA8215 from Toshiba. Even though chip is specifically designed for car audio applications it can be also used for home audio applications. Two TA8215 ICs are used here in order to obtain a 4 channel amplifier system. The circuit is designed almost exactly as per the application diagram in the ICs datasheet. Pins 7 and 19 are the Vcc pins of the ICs internal integrated power amplifier stages and these pins are connected to the positive supply. Pin 9 is the Vcc pin for ICs internal preamplifier and it is also connected to the positive supply. Pins 13 and 14 are the internal power amplifiers ground pins and they are tied together and connected to the ground.
The internal preamplifier’s ground pin (pin5) is connected to the common ground through a 10 Ohm resistor which makes the input ground separated from the common ground by a resistance of 10 ohms and this improves the noise rejection. The 100uF capacitor works as a power supply de-coupler. The resistor networks connected to the output lines of each amplifier improves the high frequency stability. The variable resistors (R3, R4, R12 and R13) works as the volume controller for the corresponding channels.
Notes :
- Assembling the circuit on a good quality PCB is a must for obtaining optimum sound quality.
- Use 12V DC for powering the circuit.
- The ICs must be fitted with adequately sized heat sinks.
- R3, R4, R12 and R13 serves as volume controllers.
- K1 to K4 can be 4 Ohm, 20W speakers.
- This amplifier circuit can be used in a variety of applications such as car audio systems, home theater systems, personal audio systems, public address systems etc. link
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