Schematic Volt: output

Showing posts with label output. Show all posts

Wednesday, October 29, 2014

Error Correction Output Stage for Mosfet and BJT Power Amplifier

For best results, any active device with the exception of the output transistors operating in class A. This is to avoid bias to saturate or block the entrance to all the clipping level, should be selected. This raises some difficulties for a BJT amplifier, where (to stay in Class A) driver stage collector currents, the base of BJT output current at maximum output current (ie in our case some of 10A) No is not exceeded. Therefore, the overall bias regime redesigned to allow space for the swing base BJT output current.

Even in these circumstances, the power dissipation in the driver’s relevant and it is doubtful if a heat sink on board (as in our design side MOSFET included) help, if maximum performance is desired 200W into 4 ohms. It is therefore assumed that the power BJT design based on our application can not be more than one goal and 100W/4ohm 50W/8ohm. Of course, for such relatively modest achievements, it is not necessary to install three pairs of output devices, a pair of (ex) MJL4281/MJL4302 or equivalent work will be done.

Adjusting the balance Hawks Word is a double potentiometer (minimum of ten rounds) with more than 0.5% of correspondence between the sections. We replaced R20 and R81 with a 2K potentiometer Bourns 10 turns and adjusted for minimum distortion 20kHz Open Loop. You will find that the minimum is strongly dependent on the frequency, always adapting to at least the higher frequency in the audible range. At low frequencies, the feedback loop gain in reducing DHT levels to help you. Measured values ??and replace the potentiometer with fixed resistors.

The minimum is usually very close, if you need 0.5% or better precision resistors. The aim should be to bring the open-loop THD-20 below 0.01% to 10 Vrms input level. We built four previous CE FPO advice and got the last open-loop THD-20-values ??at 0.0065% 0.0075% 0.0090% and 0.012% (the latter, we can not source of precision resistors required values).

The network output Zobel is the stability amps together. For the same reasons, shoud not be 2UH air core output inductor.

The error amplifier frequency compensation C17 is the signal ground of the amplifier that takes full power to the ground. It is for reasons of stability and provide a grounding shield for feedback (output port).

Monday, October 20, 2014

Photo Detector with TTL Output Circuit Diagram

This is a photo detector, a detector with TTL output light that can be used in projects for Arduino. This circuit offers low output level when there is enough light, or a light that triggers the system. He can give a command, for example, turn on the lights when it gets dark and off when clear. The output is compatible with TTL level and gives low (LO) when Q1 phototransistor detects light. RV1 with a trimpot, we can adjust the sensitivity.

Photo Detector with TTL Output Circuit Diagram

Parts List
R1 = 270 Ohm
R2-5 = 1K ohm
R3 = 10K ohm
R4 = 100 ohm
RV1 = 10K ohm
Q1 = BP103 Siemens Phototransistor
IC1 CA3130
C1-2 = 100V 100nF ceramic
IC2 = 74HCT13
D1 = 1N4148-2

Thursday, September 18, 2014

STK4050 Audio Amplifier with 200W Output

The project is based around the hybrid integrated circuit STK4050 manufactured by Sanyo to build a low noise mono audio amplifier with complete high quality. The project has a maximum output power of 200W while incorporating a volume control. The power supply used in the circuit is an on-board type and because of this, only a center tapped transformer is needed for the powering of the circuit. The sound has a very good quality and it can be proven when used in home theaters, in computers, and other audio equipments which can also be used as subwoofer amplifier. For thin-type audio sets, it can be considered as a compact package.

The heat generated in thin-type audio sets is being dispersed easily with a good heatsink design. There may be case where a shock noise may be encountered especially during switch ON and switch OFF. This can be reduced by providing a constant current circuit. The design of the circuit can be tailored for reducing occurrence of thermal shutdown, short circuit protection for loads, shock noise muting from external power supply. The load resistance should have 8 Ohms value with 55K Ohms input impedance.

Tuesday, September 2, 2014

9V output switching power supply

By using the circuit you do not bother to roll up a transformer that is used to reduce voltage AC 220V to 7V ,9 V or 12V, etc. When using a large transformer we will find it hard to make transformator. by rolling hundreds or even thousands of times roll. But if you use this circuit a little just enough to roll trafo not to small, and its be relatively small.

Part List :
R1________________________________680K
R2________________________________47K
R3________________________________100R
R4________________________________1K
R5________________________________1R
D1,D2,D3,D4,D7,D8,D9,D10__________1N4007
D5,D6_____________________________1N4148
C1________________________________2u2F 400V
C2________________________________2n2
C3________________________________47uF 25V
C4________________________________10n
C5________________________________470uF / 16V
Q1________________________________MJE13003
Q2________________________________S8050

This is construction of transformer. For the first toll 220 times , then after that wrap right on top of L2 , and L3 on L2.

Saturday, August 30, 2014

15 V output regulated power supply circuit with uA723 and 2N3055

The supply receive from 220 /120/110 Volt AC , then lowered by the transformer . Then receives +20 Volts DC from rectifier / filter section. This applied to pin 11 and 12 of the IC uA723/LM723 , as well as to the collector of the 2N3055 series pass transistor. The output through R1 and R2, providing about 7 V with respect to ground at pin 4. The reference terminal at pin 6 is tied directly to pin 5 , the non inverting input of the error amplifier . For fine trimming the output voltage , a potentiometer can be installed between R1 and R2. A 100-pF capacitor from pin 13 to pin 4 furnishes gain compensation for the amplifier.
Base drive to the 2N3055 pass transistor is furnishes by pin of the uA723. Since desired output of the supply is 1 Ampere, maximum current limit is set to 1,5 Ampere by resistor Rsc whose value is 0,422 Ohm. A 100uF electrolytic capacitor is used for ripple voltage reduction at the output. A 1 kOhm output resistor provides stability for the power supply under no - load conditions. The 2N3055 pass transistor must be mounted on an adequate heatsink.