3W STEREO AUDIO AMPLIFIER USING TDA7266D

3W-Stereo-Amp-TDA7266D-A055A-500x500

SPECIFICATIONS

  • Supply voltage range 3.5 to 5v (maximum supply 5v due to small pcb and small thermal area)
  • Output power 3+3w @thd = 10%, rl = 8ω, vcc = 3.7v (3w approx.)
  • Single supply
  • Minimum external components – no svr capacitor – no bootstrap – no boucherot cells – internally fixed gain
  • Mute functions (jumper close)
  • Short circuit protection
  • Thermal overload protection

SCHEMATIC

3W-Stereo-Amp-TDA7266D-SCH

PARTS LIST

3W-Stereo-Amp-TDA7266D-bom

PHOTOS

3W-Stereo-Amp-TDA7266D-A055B-500x500

VIDEO

PCB

SOUND TO LIGHT EFFECT

This PROJECTS  will turn your favorite music into light effects, a microphone picks up the sound and gives  light effects with 6 Red LEDs, ideal for creating fun atmosphere at parties & discos. Supply 9V-12V DC.

FEATURES

  • Supply 9V-12V DC (PP3 9V Battery)
  • On Board Preset for Gain Adjust
  • 6 On Board LEDs
  • On Board Condenser Microphone
  • SMD based small Board
  • PCB Dimension 45.72 X 28.58 MM
  • CN1 Supply Input
  • PR1 Sensitivity Adjust

SOUND-TO-LIGHT-EFFECT-PIC

SCHEMATIC

SOUND-TO-LIGHT-EFFECT-SCHEMATIC

PARTS LIST

SOUND-TO-LIGHT-EFFECT-BOM

Video

PCB

LOW NOISE MINI ELECTRET MICROPHONE PREAMPLIFIER

The single supply microphone pre-amplifier amplifies the output signal of an electret capsule microphone to audio line levels. An op amp is used as a trans-impedance amplifier to convert the output current from the microphone in to a signal level voltage. The circuit works with 9V so it is good choice for battery operated systems.

FEATURES

  • Supply 9V DC
  • Current Approx. 3mA
  • On Board Microphone
  • Very thin and narrow PCB

SCHEMATIC

 

PARTS LIST

bom

PHOTOS

img_5974

VIDEO

PCB

HIGH PERFORMANCE STEREO AUDIO AMPLIFIER USING LM3886

The LM3886 is a high-performance audio power amplifier capable of delivering 68W of continuous average power to a 4Ω load and 38W into 8Ω with 0.1% THD+N from 20Hz–20kHz.

The performance of the LM3886, utilizing its Self Peak Instantaneous Temperature (°Ke) (SPiKe) protection circuitry, puts it in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA). SPiKe protection means that these parts are completely safeguarded at the output against overvoltage, under voltage, overloads, including shorts to the supplies, thermal runaway, and instantaneous temperature peaks.

The LM3886 maintains an excellent signal-to-noise ratio of greater than 92dB with a typical low noise floor of 2.0µV. It exhibits extremely low THD+N values of 0.03% at the rated output into the rated load over the audio spectrum, and provides excellent linearity with an IMD (SMPTE) typical rating of 0.004%.

Note : Amplifier Requires a Large Size Heat sink

FEATURES

  • 68W Cont. Avg. Output Power into 4Ω at VCC = ±28V
  • 38W Cont. Avg. Output Power into 8Ω at VCC = ±28V
  • 50W Cont. Avg. Output Power into 8Ω at VCC = ±35V
  • 135W Instantaneous Peak Output Power Capability
  • Signal-to-Noise Ratio ≥ 92dB
  • An Input Mute Function ( J1 & J2 Jumper)
  • Output Protection from a Short to Ground or to the Supplies via Internal Current Limiting Circuitry
  • Output Over-Voltage Protection against Transients from Inductive Loads
  • Supply Under-Voltage Protection, not Allowing Internal Biasing to Occur when |VEE| + |VCC| ≤ 12V, thus Eliminating Turn-On and Turn-Off Transients
  • Input Slandered Audio Line signal

SCHEMATIC

PARTS LIST

PCB

TINY PROFESSIONAL MICROPHONE PREAMPLIFIER

The board has been design around INA217 low distortion, low noise instrumentation amplifier. The INA217 is ideal for low-level audio signals such as balanced low-impedance microphones. Many industrial, instrumentation, and medical applications also benefit from its low noise and wide bandwidth. Unique distortion cancellation circuitry reduces distortion to extremely low levels, even in high gain. The INA217 provides near-theoretical noise performance for 200Ω source impedance. The INA217 features differential input, low noise, and low distortion that provides superior performance in professional microphone amplifier applications. An OPA2137 op-amp used as a feedback to eliminate the offset voltage. Phantom power is not part of the circuit its just for reference.

FEATURES

  • Supply Dual +/-15V DC
  • Output Unbalance Single Ended
  • PR1 Gain Adjust G=1+10000/Rg PR1

SCHEMATIC

PARTS LIST

GAIN CONTROL

PHOTOS

PCB

16×2 LCD SHIELD FOR ARDUINO NANO

This 16×2 LCD shield for Arduino Nano includes various add-ons, like 5 Tactile Switches, 3 Trimmer Potentiometers, LM35 Temperature sensor and the 16×2 LCD itself. It’s a compact shield designed to fit in small enclosures and it is intended to develop measuring devices like thermometers, voltmeters, timers, up down counters and other various project requiring LCD, switches, trimmer pots etc.

Note : Trimmer Potentiometer can be replaced with Header connector to interface various sensors.

FEATURES

  • Input Supply 7-12V DC
  • 16×2 LCD Header Connector
  • 5 Vertical Mounted Push Switch
  • 3 x 5K Ohms Trimmer Potentiometers
  • LM35 Temperature Sensor
  • LCD Connected to D2,D3,D4,D5,D11,D12
  • LM35 Temperature Sensor Connected Analog- A4 of Arduino
  • Trimmer Potentiometers Connected to Analog Pin A0,A1,A2
  • Push Switch Connected to A4, D13, D8, D7, D6
  • PR1 Trimmer Potentiometer To Adjust The LCD Contrast

SCHEMATIC

PARTS LIST

PHOTOS

 

PCB

HI-FI STEREO HEADPHONE AMPLIFIER USING LME49600

This project is the ideal solution for high output, high performance high fidelity stereo head phone amplifier. The project consists of Op-Amp LME49720 and LME49600 as output driver. The LME49600 is able to drive 32Ω headphones to a dissipation of greater than 500mW at 0.00003% THD+N while operating on ±12V power supply voltages.  The LME49600 is a high performance, low distortion high fidelity 250mA audio buffer. The LME49600 is designed for a wide range of applications and is fully protected through internal current limit and thermal shutdown.

FEATURES

  • Supply +/-12V
  • Output Load 32Ohms Headphone
  • Input Line Level Audio Signal
  • Onboard Volume Control

SCHEMATIC

PARTS LIST

CONNECTIONS

PHOTOS

PCB

LOW COST/VOLTAGE 3W CLASS-D STEREO AUDIO AMPLIFIER FOR PORTABLE GADGETS

This low cost low voltage 3W class-D stereo amplifier is based on PAM8403 IC, The PAM8403 is a 3W, class-D audio amplifier. It offers low THD+N, allowing it to achieve high-quality sound reproduction. The new filter-less architecture allows the device to drive the speaker directly, requiring no low-pass output filters, thus saving system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8403 is much better than that of Class-AB cousins. It can extend the battery life, which makes it well-suited for portable applications. Trimmer Potentiometer helps to adjust the volume control, CN1 provided to feed the audio signal, CN2 power supply, Mute and shutdown in, LS1 and LS2 to connect the speaker. Shutdown and Mute pin required high level signal input, and can be connect to VDD power pins for normal operation, can be connect to GND for shutdown or mute the audio. The amplifier works well with standard audio signal input.

SPECIFICATIONS

  • Supply 3.6V 5V DC
  • 3W Output at 10% THD with a 4Ω Load and 5V Power Supply
  • Filter less, Low Quiescent Current and Low EMI
  • On Board Trimmer potentiometer to Adjust The Volume
  • Low THD+N
  • Very Small Size Board
  • Superior Low Noise
  • Efficiency up to 90%
  • Short Circuit Protection
  • Thermal Shutdown

SCHEMATIC

Parts List

CONNECTIONS

PHOTOS

VIDEO

PCB

DIFFERENTIAL MICROPHONE PRE-AMPLIFIER

The project shown here is a microphone preamplifier that provides high quality amplification, optimized for use in computers, media and mobile applications. The pre-amplifier provides a differential input stage, making the device particularly effective when layout constraints force the microphone amplifier to be physically remote from the ECM microphone. This project features adjustable gain using PR1 trimmer potentiometer, very high power-supply rejection (95dB), and common-mode rejection (79dB), making it ideal for low-noise applications. Board is provided with condenser microphone as well as connector to connect external microphone, selection of external or internal microphone is possible with the help of on board Jumper. Circuit requires 5V DC input. The circuit provides differential output, use +OP/GND for single ended output. External microphone gain can be changed using R5.

The project features two selectable inputs onboard microphone or external microphone, differential outputs, adjustable gain, an integrated low noise bias source, and a low-power shutdown mode. Two input paths provide both differential and single ended microphone sensing. The high-noise rejection of the differential input is ideally suited to an internal microphone where system noise and long-run PC board traces can degrade low-level signals. The single-ended input provides a simple connection to an external microphone, can be connected to CN2.

FEATURES

  • Supply 5V DC
  • On Board Power LED
  • PCB dimensions: 34.62 x 15.86 mm

INPUT/OUTPUT CONNECTIONS

  • MK1: Onboard Microphone
  • CN3: Differential Output
  • CN1 : Power Input 5V DC ( 2.4V-5V Possible)
  • CN2 : External Microphone
  • D1 : Power LED
  • PR1 : On Board Microphone Gain Adjust
  • J1 : Onboard Mic./ External Microphone selection

SCHEMATIC

PARTS LIST

CONNECTIONS

PHOTOS

VIDEO

PCB

MINI SPEAKER ATTACHED AUDIO AMPLIFIER USING TS4871

This Mini Audio Power Amplifier is capable of delivering 1W of continuous RMS Output Power into 8 ohms load @ 5V. The Amplifier is built using TS4871 IC from ST.  This Audio Amplifier is exhibiting 0.1% distortion level (THD) from a 5V supply for a Pout = 250mW RMS. An external standby mode control reduces the supply current to less than 10nA. An internal thermal shutdown protection is also provided. The amplifier has been designed for high quality audio applications such as mobile phones, media players and portable device. The gain is set to 6dB but unity-gain stable amplifier can be configured by external gain setting resistor R4. 28mm ID hole provided for easy mounted of PCB directly on speaker.

Connections: D1 Power LED, CN1 Power input, LS1 Speaker, CN2 Audio Signal Input.

Note : Default Gain 6dB, Change R4 to 110K to set the Gain to 20dB.

SPECIFICATIONS

  • SUPPLY 5V
  • 1W RAIL TO RAIL OUTPUT POWER
  • Vcc=5V, THD=1%, f=1kHz, with 8W LOAD
  • ULTRA LOW CONSUMPTION IN STANDBY MODE (10nA)
  • 75dB PSRR @ 217Hz from 5V to 2.6V
  • Gain 6dB
  • ULTRA LOW POP & CLICK
  • ULTRA LOW DISTORTION (0.1%)
  • UNITY GAIN STABLE
  • PCB Dimensions 42.42mm OD & 28mm ID

SCHEMATIC

PARTS LIST

CONNECTIONS

PHOTOS

 

 

VIDEO

PCB

USB POWERED AUDIO AMPLIFIER USING MAX4298

USB powered mini speaker amplifier is conveniently powered by USB and it is simple to set up. USB powered speakers are convenient for listening to your media while at home or on the go. Conventional computer speakers that require an electrical outlet to work can be prohibitive because they force you to be close to the power supply at all times. This audio amplifier is directly connected to a USB port and to the input signal and you have really high-quality sound output from mini speakers or headphones. It is a class AB amplifier that can drive 16 to 32 ohms load.

The headphone driver amplifier is a class AB amplifier designed to drive 16Ω loads. The amplifiers have innovative architectures for both the input and output stages to achieve ultra-high PSRR while maintaining rail-to-rail output drive capability. The output stage can drive high capacitive loads encountered when driving long cables used for desktop speakers or headphones.

The MAX4298 is an audio system ICs designed for single +5V applications. The MAX4298 features a stereo headphone driver. The MAX4298 IC designed specifically for harsh digital environments where board space is at a premium and the digital power supply is noisy. The design uses innovative design techniques to achieve ultra-high power-supply rejection across the audio signal band while, at the same time, delivering a high-current Rail-to-Rail output drive capability. The chip is designed to drive highly capacitive loads that may be encountered when driving long cables to a remote load such as desktop/notebook headphones or speakers. These devices are fully compliant with PC99 standards.

The amplifiers exhibit 115dB of DC power-supply rejection and 80dB at 100kHz. The output amplifiers are capable of driving a 1.5VRMS signal into a 10-kilohm load with 0.0008% THD+N. They can also drive 32Ω headphones to 1.2VRMS with 0.02% distortion.

The MAX4298 has short-circuited current protection on all outputs. They also have a thermal shutdown function designed to protect the chip from junction temperatures in excess of +150°C that may arise from temporary short circuits or operation beyond the power dissipation limit of the package. The driver amplifier outputs limit at around ±220mA.

FEATURES

  • Supply USB Power 4.5V to 5.5V
  • Ultra-High PSRR Stereo Headphone Driver
  • 93dB typ PSRR at 20kHz Operates Directly from Noisy Digital Supplies
  • Clickless/Popless Power Up, Power Down, Mute, and Unmute
  • PC99 Compliant Output Drivers:
  • Better than 1VRMS Output into 16Ω Load and 1.5VRMS and 0.0008% THD+N into 10kΩ Load

SCHEMATIC

PARTS LIST

CONNECTIONS

 

PHOTOS

VIDEO

PCB

STEREO VOLUME AND BALANCE CONTROL WITH ROTARY ENCODER USING MAX5440

The project described here is a compact stereo volume and balance control with a rotary encoder. It provides 32 log potentiometer steps with buffered wiper output. The project can easily replace mechanical potentiometer. 5 LEDs indicate the volume level or balance settings , depending on the status of the mode indicator D1 LED. The MAX5440 includes debounced pushbutton inputs for mute and mode. The mute input allows a single pushbutton to change between volume control and the -90dB (typ) mute setting. The mode input toggles between volume and balance control. A click-and-pop suppression feature minimizes the audible noise generated by wiper transitions.

MAX5440 DESCRIPTION

The MAX5440 dual, 40kΩ logarithmic taper volume control features a debounced up/down interface for use with a simple rotary encoder without using a microcontroller (µC). Each potentiometer has 32 log-spaced tap points with a buffered wiper output and replaces mechanical potentiometers. An integrated bias generator provides the required ((VDD + VSS) / 2) bias voltage, eliminating the need for costly external op-amp circuits in unipolar audio applications. A mode-indicator LED output specifies volume or balance control. Five integrated LED drivers indicate volume level or balance settings, depending on the status of the mode indicator.

FEATURES

  • Logarithmic Taper Volume Control with (31) 2dB Steps
  • Low-Power Wiper Buffers Provide 0.003% THD
  • Single +2.7V to +5.5V Supply Voltage Operation
  • Low 0.5µA Shutdown Supply Current
  • Integrated Bias Voltage Generator
  • Five-Segment LED Volume/Balance Indicator
  • Click less Switching
  • 40kΩ End-to-End Fixed Resistance Value
  • Mute Function Toggles to -90dB (typ)
  • Power-On Reset to -12dBFS Wiper Position

SCHEMATIC

PARTS LIST

CONNECTIONS

PHOTOS

 

 

PCB

How to Change the Bluetooth 5.0 EQ Settings

There is an in-built equalizer in Tinysine Bluetooth 5.0 module. If you have the CSR USB-SPI programmer, you can change the equalizer settings by yourself. TSA6175 module uses the CSR8675 Bluetooth chip. It needs a new version software to change the EQ settings. This tutorial will teach you how to set it.

 

Hardware and Software required:

Step 1:

Connect the CSR USB-SPI programmer and Tag-Connect line with an AudioB Plus convert board, then connect CSR USB-SPI to your computer by a mini USB cable, and windows will auto-detect it and install the drivers.

Step 2:

Connect TC2050-IDC-NL’s connector to the AudioB5 programming port. You need to locate the single steel alignment pin of the connector into the single hole of the PCB footprint, then press down softly to engage the spring-pin contacts. Make sure the first 6 pins have good contact with the corresponding pads. Then the blue LED and the red LED will flash alternately.

 

Step 3:

Let your smartphone get connected to the Bluetooth module and play the music. You can hear music out from the speakers. And then you can open the “CSRA64xxx Universal Front End” software.

Step4:

DSP->Connection. Select USB SPI and connect it.

Step5: Click “Monitor DSP” button.

Step6:

There are many settings that can be changed on the following page. Here we click “User PEQ” to enter the EQ value setting page.

Step 7:

In the settings page, Unclick the Flat option. Select “Bass Boost” in the Presets. Then click the “Apply” button. You will hear the Bass boost works immediately. You can also try other options.

Step 8:

Click “Download Params” to store the new settings to the Bluetooth module. Then you can remove the programmer and use the Bluetooth audio amplifier with new EQ values.

AUDIO VU/SOUND LEVEL METER WITH LM339

This is an “Audio VU Meter” or “Sound Level Meter”, it is a general-purpose bar-graph Audio VU meter designed for fun projects. All you need is to hook up one wire to the output of the audio amplifier’s speaker pin along with GND and see the magic. The response of the circuit is very fast and it provides beautiful visual representation from audio input signal.

A simplified schematic is provided to give the general idea of the operation.  The signal is applied to a series of 20 comparators, each of them is biased to a different comparison level by the resistor string. In the circuit diagram, the resistor string is connected to the 100K potentiometer which provides reference voltage 1.9V to 12V.

As the input voltage varies from 0 to 1.9V, the comparator’s outputs are driven low one by one, switching on the LED indicators. This circuit will work with the audio signal level from 1.9V to 12V, it will not work with the audio line signal.  String resistor values calculated to use this project with audio amplifier of 1W to 10W. PR2 provided to adjust the input audio signal level. Testing the board is simple, keep both potentiometer PR1 and PR2 at the center, hook-up 2 wires GND and Input signal to Audio amplifier speaker out, adjust the PR1 so all LEDs are in ON condition at the full audio signal level.

Note: This project can be used in many other applications by altering the string resistors value. Possible applications are bar graph voltmeter, battery level monitor, sensor value monitor.

FEATURES

  • Supply 9V to 12V DC
  • Load Current 200Ma (When all LED’s are ON)
  • Input Signal Level 1.9V to 12V
  • Can be used with 1W to 10W Audio Amplifier

SCHEMATIC

PARTS LIST

CONNECTIONS

GERBER VIEW

PHOTOS

VIDEO

PCB

INFRARED ROBOT CONTROLLER SHIELD FOR ARDUINO NANO

This compact Infrared robot controller is based on Arduino Nano and L298 H-Bridge. The Nano shield can be used in various DC Motor driver applications using infra-red remote control or speed controller using trimmer potentiometer and direction control with help of slide switch.   The board can drive two small size DC-Motors with current rating up to 1A each. Board also has jumpers to drive single DC Motor up to 2A. Additional 10K trimmer potentiometer and slide switch provided for DC Motor speed and direction control. The L298 IC mounted under the PCB so board can be mounted on heat sink directly in horizontal position. Screw terminal provided to connect motors. Circuit requires 7-18V DC , close the Jumper J-5V to power up the Arduino Nano. Close J1, J2, J3, J4, J5, jumpers for single motor operations.

FEATURES

  • Motor supply: 7 to 18 VDC
  • Output DC drive to motor: up to 2 A each (Peak) for Single Motor
  • Dual DC Motor driver 1Amp each
  • On Board 5V Regulator (Close J-5V to Use On Board 5V Regulator for Nano)
  • Digital PWM Pins D6,D11 Connected to Enable A and Enable B of L298 for PWM Input
  • Digital Pin D4,D5 Connected to I1 and I2 of L298 for Motor 1 Direction Control
  • Digital Pin D9,D10 Connected to I3 and I4 of L298 for Motor 2 Direction Control
  • Infra-Red Sensor Connected to Digital Pin D13 Of Arduino Nano
  • Slide Switch Connected to Analog pin A7 Of Arduino Nano
  • Trimmer Potentiometer Connected to Analog Pin A0 of Arduino Nano
  • External Diode provided for back EMF protection
  • Screw terminal connector for easy connection to Motor
  • D1 Power LED
  • PCB Dimensions 63.42mm X 41.76mm

SCHEMATIC

PARTS LIST

CONNECTIONS

 

PHOTOS

 

PCB

ISOLATED HIGH POWER DC SOLID-STATE RELAY SHIELD FOR ARDUINO

 

DC Converters, inverters, DC motor control, solenoid, LED Dimmer, battery chargers and it can control inductive and resistive loads. On board high current fast recovery diode across the load provided for back EMF protection. The board can control load up to 25A with input supply up to 48V DC. High voltage DC input supply up to 90V is possible by altering DC bus capacitor voltage.
Input PWM frequency up to 100 KHz duty cycle 0-100%. Mosfet power driver is isolated from Gate driver input. Gate driver circuitry requires 15V DC. Load supply 15V to 48V DC. Jumper J1 helps to use common supply for Arduino and gate driver. Screw terminal CN3 helps to connect load supply and load. Anode of gate driver connected to D3-PWM pin of Arduino to feed PWM signal or ON/OFF. P1 Potentiometer connected to Analog pin A0 of Arduino to adjust the PWM. Higher current Mosfets can be used to get more output current. Gate input requires TTL level signal.

Features:

  • Gate Driver Supply 15V
  • Load Supply 15V-48V
  • Load Current 25Amps
  • PWM Control: Arduino D3-PWM Pin
  • Potentiometer: Arduino Analog Pin A0
  • Jumper J1 : Close If common supply Arduino + Gate Driver
  • CN1: Supply 15V Gate Driver
  • CN3: Load
  • CN2: Load Supply Input
  • CN4: PWM Input
  • CN5: Arduino Supply Input

SCHEMATIC

PARTS LIST

CONNECTIONS

PHOTOS

PCB

IR REMOTE EXTENDER

This project describes how to build an IR remote control extender / repeater to control your electronic appliances from a remote location.
An IR detector module receives IR signal from remote control and two IR leds are re-emitting the signal to the appliance. You can place the IR emitting leds close to the device you would like to control using some wire and keep main unit close to remote control location. In the image at the left LEDs are soldered on the board. The circuit consists of three main parts, the IR receiver module, a 555 timer configured as an oscillator and the output / emitter stage. We will describe circuit operation below.

Circuit is designed by Andy Collinson and can be found here:http://www.zen22142.zen.co.uk

IR SIGNAL

The IR signal emitted from a remote control caries the information needed to control the appliance. This signal consists of pulses that code 0 and 1 bits, instructing the appliance to do a certain operation. One of the most common protocols used to code the IR signal is Philips – RC5 protocol. The signal consists of two parts, the control pulses and the carrier wave as seen in the image below.

image_1

A common frequency used for the carrier is 38KHz and control pulses frequency is in the range of 1-3KHz. The carrier signal is modulated by the control pulses and the resulting signal is emitted by remote in IR band of electromagnetic spectrum. IR band is invisible to human eye. You can see if an IR led is emitting light or not using a camera. Point the camera to the led and you will see that light comes off.

CIRCUIT DESCRIPTION

IR signal is received by TSOP1738. TSOP1738 is an infrared receiver at 38KHz. At the output of infrared receiver we get a demodulated signal that means we get the low frequency control pulses. Infrared receiver is powered from C1, R1 and Z1 that forms a 5V power supply. With no signal received, infrared detector output is high and Q1 is on, so pin 4 of IC is LOW and 555 timer is in reset state. Q1 also acts as a level shifter that converts 5V signal of TSOP1738 to 9V signal for IC1.

schematic

When HIGH control pulses are appearing on TSOP1738 output then timer 555 (which is configured as an oscillator) starts to oscillate at a preset frequency, for the duration of each data pulse. That means that at pin 3 we get a signal that is similar to modulated source signal. It has a carrier component and a control pulses component. Oscillating frequency of 555 timer is set by R4 and C2 and pulse period is given by:

T = 1,4 R4 C2

Trimmer R5 is used to fine tune oscillating frequency at 38KHz. That’s equal to carrier frequency.

The output stage is formed from R6, Q2, one red LED, two IR LEDs and two current limiting resistors R7 and R8. Q2 is connected as voltage follower, that means when base of Q2 is HIGH transistor is ON allowing current to flow through LEDs. LED current is set by R7 and R8 according the following formula:

So IR LEDs are emitting a signal that is similar to the signal received by TSOP1738, that means it repeats the signal received at higher infrared radiation intensity. The red LED is used as an optical indicator of output signal. Circuit can be powered from a 9V battery.
photo_2
photo_3

PARTS LIST

Part Value
R1 1k
R2 3k3
R3 10k
R4 15k
R5 4k7 trimmer
R6 2k2
R7 470R
R8 47R – 1/2W
C1 47uF – 16V
C2 1n – polyester
C3 100uF – 16V
C4 47uF – 16V
Z1 5V1 zener
Q1 BC549C
Q2 BC337
IC1 NE555
LED1 red LED
LED2-3 IR LED
IR receiver TSOP138 or IR38DM

 

image_3

TESTING

Before powering the circuit, remove IR LEDs. With no input red LED should be off. Now press a button on a remote control, red led should flicker. If that’s the case then your circuit should be working ok. Install IR LEDs. We found during testing that IR signal emitted from remote and IR signal emitted from circuit are interfering each other and that’s make receiving device not to react on receiving the signal, this happens when IR from remote and IR from circuit’s LEDs are on the same room. To solve that we must isolate the IR beam of remote control. To do that we used a thin pipe in front of infrared sensor as seen in photo below, so that the beam emitted from remote hits the sensor directly. Another solution to this would be to put the emitting LEDs on a different room.

photo_4

INSTALLATION

We installed the circuit on the wall the way you see on the photo below. You can see that remote control led is optically isolated from surround. You can also notice that one LED is remotely placed near the device we would like to control.

photo_5

REFERENCES

PCB

MAGNETIC FIELD SENSOR USING AD22151

Magnetic field sensor project using AD22151 IC from Analog Devices, The AD22151 is linear magnetic field transducer. The sensor output is a voltage proportional to a magnetic field applied perpendicularly to the package top surface. The sensor combines integrated bulk Hall cell technology and instrument technology to minimize temperature related drifts associated with silicon Hall cell characteristics.

FEATURES

  • Supply 5V DC @ 25mA
  • Power Led On Board
  • Header connector for supply and output
  • Normal Output 1.800V
  • South side Magnet Output 4.800V
  • North side Magnet Output 0.042V

APPLICATIONS

  • Throttle Position Sensing
  • Pedal Position Sensing
  • Suspension Position Sensing
  • Valve Position Sensing
  • Absolute Position Sensing
  • Proximity Sensing

SCHEMATIC

Magnetic-field-sensor

PARTS LIST

Magnetic-field-sensor-bom

CONNECTIONS

Magnetic-field-sensor-connections

VIDEO

PCB

+/- 1.7G DUAL-AXIS IMEMS ACCELEROMETER USING ADXL203

The ADXL203 Module  is high precision, low power, complete dual-axis accelerometers with signal conditioned voltage outputs, all on a single, monolithic IC. The ADXL203 measure acceleration with a full-scale range of ±1.7 g, ±5 g, or ±18 g. The ADXL203 can measure both dynamic acceleration (for example, vibration) and static acceleration (for example, gravity).The typical noise floor is 110 μg/√Hz, allowing signals below 1 mg (0.06° of inclination) to be resolved in tilt sensing applications using narrow bandwidths (<60 Hz).The user selects the bandwidth of the accelerometer using Capacitor CX and Capacitor CY at the XOUT and YOUT pins. Bandwidths of 0.5 Hz to 2.5 kHz can be selected to suit the application.

FEATURES

  • Supply 4.75V To 5.25V
  • Output 1.4V To 3V ( 2.2V Center ) Aproxx.
  • High performance, dual-axis accelerometer on a single IC chip
  • 5 mm × 5 mm × 2 mm LCC package
  • 1 mg resolution at 60 Hz
  • Low power: 700 μA at VS = 5 V (typical)
  • High zero g bias stability
  • High sensitivity accuracy
  • −40°C to +125°C temperature range
  • X and Y axes aligned to within 0.1° (typical)
  • Bandwidth adjustment with a single capacitor
  • Single-supply operation
  • 3500 g shock survival
  • Sensitivity is essentially ratiometric to VCC For VCC = 4.75 V to 5.25 V, sensitivity is 186 mV/V/g to 215 mV/V/g.
  • 4 Actual frequency response controlled by user-supplied external capacitor (CX, CY).
  • 5 Bandwidth = 1/(2 × π × 32 kΩ × C). For CX, CY = 0.002 μF, bandwidth = 2500 Hz. For CX, CY = 10 μF, bandwidth = 0.5 Hz. Minimum/maximum values are not tested. 6 Self-test response changes cubically with VS.
  • 7 Larger values of CX, CY increase turn-on time. Turn-on time is approximately 160 × CX or CY + 4 ms, where CX, CY are in μF.

APPLICATIONS

  • Vehicle dynamic controls
  • Electronic chassis controls
  • Platform stabilization/leveling
  • Navigation
  • Alarms and motion detectors
  • High accuracy, 2-axis tilt sensing
  • Vibration monitoring and compensation

THEORY OF OPERATION

The ADXL203 are complete acceleration measurement systems on a single, monolithic IC. The is a single-axis accelerometer, and the ADXL203 is a dual-axis accelerometer. Both parts contain a polysilicon surface-micro-machined sensor and signal conditioning circuitry to implement an open-loop acceleration measurement architecture. The output signals are analog voltages that are proportional to acceleration. The ADXL203 are capable of measuring both positive and negative accelerations from ±1.7 g to at least ±18 g. The accelerometer can measure static acceleration forces, such as gravity, allowing it to be used as a tilt sensor. The sensor is a surface-micromachined polysilicon structure built on top of the silicon wafer. Polysilicon springs suspend the structure over the surface of the wafer and provide a resistance against acceleration forces. Deflection of the structure is measured using a differential capacitor that consists of independent fixed plates and plates attached to the moving mass. The fixed plates are driven by 180° out-of-phase square waves. Acceleration deflects the beam and unbalances the differential capacitor, resulting in an output square wave whose amplitude is proportional to acceleration. Phase-sensitive demodulation techniques are then used to rectify the signal and determine the direction of the acceleration.

The output of the demodulator is amplified and brought off-chip through a 32 kΩ resistor. At this point, the user can set the signal bandwidth of the device by adding a capacitor. This filtering improves measurement resolution and helps prevent aliasing. PERFORMANCE Rather than using additional temperature compensation circuitry, innovative design techniques have been used to ensure that high performance is built in. As a result, there is essentially no quantization error or nonmonotonic behavior, and temperature hysteresis is very low (typically less than 10 mg over the −40°C to +125°C temperature range). Figure 11 shows the 0 g output performance of eight parts (x and y axes) over a −40°C to +125°C temperature range. Figure 13 demonstrates the typical sensitivity shift over temperature for VS = 5 V. Sensitivity stability is optimized for VS = 5 V but is still very good over the specified range; it is typically better than ±1% over temperature at VS = 3 V.

SETTING THE BANDWIDTH USING CX AND CY

The ADXL203 has provisions for band limiting the XOUT and YOUT pins. Capacitors must be added at these pins to implement low-pass filtering for antialiasing and noise reduction. The equation for the 3 dB bandwidth is

f–3 dB = 1/(2π(32 kΩ) × C(X, Y))

or more simply,

f–3 dB = 5 μF/C(X, Y)

The tolerance of the internal resistor (RFILT) can vary typically as much as ±25% of its nominal value (32 kΩ); thus, the bandwidth varies accordingly. A minimum capacitance of 2000 pF for CX and CY is required in all cases.

Table 7. Filter Capacitor Selection, CX and CY

Bandwidth (Hz)

Capacitor (μF)

SCHEMATIC

PARTS LIST

SENSOR ORIENTATION

PINOUT

PHOTOS

VIDEO

PCB

DUAL-CHANNEL QUADRATURE HALL-EFFECT BIPOLAR SWITCH MODULE FOR MAGNETIC ENCODER

The A1230 is a dual-channel, bipolar switch with two Hall-effect sensing elements, each providing a separate digital output for speed and direction signal processing capability. The Hall elements are photo lithographically aligned to better than 1 µm. maintaining accurate mechanical location between the two active Hall elements eliminates the major manufacturing hurdle encountered in fine-pitch detection applications. The A1230 is a highly sensitive, temperature stable magnetic sensing device ideal for use in ring magnet based, speed and direction systems located in harsh automotive and industrial environments.

The A1230 monolithic integrated circuit (IC) contains two independent Hall-effect bipolar switches located 1 mm apart. The digital outputs are out of phase so that the outputs are in quadrature when interfaced with the proper ring magnet design. This allows easy processing of speed and direction signals. Extremely low-drift amplifiers guarantee symmetry between the switches to maintain signal quadrature. The Allegro patented, high-frequency chopper-stabilization technique cancels offsets in each channel providing stable operation over the full specified temperature and voltage ranges.

Additionally, the high-frequency chopping circuits allow an increased analog signal-to-noise ratio at the input of the digital comparators internal to the IC. As a result, the A1230 achieves industry-leading digital output jitter performance that is critical in high performance motor commutation applications. An on-chip low dropout (LDO) regulator allows the use of this device over a wide operating voltage range. Post-assembly factory programming at Allegro provides sensitive switch points that are symmetrical between the two switches.

Bipolar Switch Applications and Working from Allegro Micro
There are four general categories of Hall-effect IC devices that provide a digital output: unipolar switches, bipolar switches, omnipolar switches, and latches. Bipolar switches are described in this application note. Similar application notes on unipolar switches, omnipolar switches, and latches are provided on the Allegro™ website.

Bipolar sensor ICs are designed to be sensitive switches. (Note that the term “bipolar” refers to magnetic polarities, and is not related to bipolar semiconductor chip structures.) A bipolar switch has consistent hysteresis, but individual units have switchpoints that occur in either relatively more positive or more negative ranges. These devices find application where closely-spaced, alternating north and south poles are used, resulting in minimal required magnetic signal amplitude, ΔB, because the alternation of magnetic field polarity ensures switching, and the consistent hysteresis ensures periodicity.

Applications for detecting the position of a rotating shaft, such as in a brushless dc motor (BLDC) are shown in figure 1. The multiple magnets are incorporated into a simple structure referred to as a “ring magnet,” which incorporates alternating zones of opposing magnetic polarity. The IC package adjacent to each ring magnet is the Hall bipolar switch device. When the shaft rotates, the magnetic zones are moved past the Hall device. The device is subjected to the nearest magnetic field and is turned-on when a south field is opposite, and turned-off when a north field is opposite. Note that the branded face of the device is toward the ring magnet.

FEATURES

  • It Provides Dual A & B Channel Like optical Encoder
  • Simple Module help to make Magnetic Encoder for Motion Control application
  • Supply 5V DC
  • TTL Output
  • Two matched Hall-effect switches on a single substrate
  • 1 mm Hall element spacing
  • Superior temperature stability and industry-leading jitter performance through use of advanced   chopper stabilization topology Integrated LDO regulator provides 3.3 V operation
  • Integrated ESD protection from outputs and VCC to ground
  • High-sensitivity switch points
  • Robust structure for EMC protection
  • Solid-state reliability
  • Reverse-battery protection on supply and both output pins

APPLICATIONS

  • Brushless DC Motor Rotation
  • Speed Sensing
  • Pulse Counter
  • Magnetic Encoders

SCHEMATIC

PARTS LIST

DIAGRAM

PCB

Search for products

Back to Top
Product has been added to your cart