Monday, February 20, 2012

BA5417 Stereo Power Amplifier Circuit

BA5417 stereo amplifier circuit has of good features like thermal shut down, standby function, soft clipping, wide operating voltage range etc. The circuit can be deliver 5W × 2 when VCC = 12V and RL = 4Ω, or 2.8W x 2 when VCC = 9V RL = 3Ω.This and amplifier circuit has excellent sound quality, and low THD (total harmonic distortion) around 0.1% at F = 1kHz; Pout = 0.5W
BA5417 Stereo Power Amplifier Circuit
C-in are DC decoupling capacitors which block any DC level present in the input signals. C3 and C5 couples the amplifiers left and right power outputs to the corresponding loud speakers. C2 and C6 are bootstrap capacitors. Bootstrapping is a method in which a portion of the amplifiers is taken and applied to the input. The prime objective of bootstrapping is to improve the input impedance. Networks R1,C1 and R2,C7 are meant for improving the high frequency stability of the circuit. C4 is the power supply filter capacitor. S1 is the standby switch. C8 is a filter capacitor. RF1 and RF2 sets the gain of the left and right channels of the amplifier in conjunction with the 39K internal feedback resistors.


3VDC Stereo Headphone Amplifier by IC LM4910

This is a stereo headphone amplifier circuit of using LM4910 IC. This circuit is very simple so it is very easy to make even for beginners once. because the voltage source is used only 3 VDC you can use 2 x A3 battery in series stacking.
Circuit diagram of 3VDC Stereo Headphone 
Amplifier by LM4910 
IC LM4910 Pinout
LM4910 Boomer belonging to the series of National Semiconductors is an integrated stereo amplifier is primarily intended for headphone stereo applications. The IC can be operated from 3.3V ans its 0.35mW can deliver output power into a 32 ohm load. The LM4910 has very low distortion (less than 1%) and the shutdown current is less than 1uA. This low shutdown current makes it Suitable for battery operated applications.

C1 and C2 are the input DC decoupling capacitors for the left and right input channels. R1 and R2 are the respective input resistors. R3 is the feed back resistor for left channel while R4 is the feed back resistor for the right channel. C3 is the power supply filter capacitor. The feedback resistors also sets the closed loop gain in conjunction with the corresponding input resistors.


Wednesday, January 25, 2012

10 LED VU Meter Using IC LM3914

This 10 LED VU meter circuit has only a few parts but is useful as an indicator for the measurement of entering acoustic signals. The circuit is a perfect one chip replacement for the standard analog meters. It is completely solid state and will never wear out
LM3914 VU Meter Circuit

The circuit is built around an LM3914 IC. The input signal from the VU meter is put on pin 5 of IC1. Through pin 9 of IC1 is the display mode sets (bar or dot instructions). In the drawn state IC1 works in the dot mode. When pin 9 is coupled to pin 3, the IC works in bar mode. Obviously the whole circuit consumes less power in dot mode.

List Component
C1        : 2.2uF/ 25V Electrolytic Capacitor
R1        : 1K  Resistor
D1        : 1N4002 Diode
LED1-LED  : 10 x  LED or LED Array
U1        : LM3915 
  • V+ can be anywhere from 3V to 20V. 
  • The input is designed for standard audio line voltage with has a maximum input voltage of 1.3V.
  • Pin 9 can be disconnected from ground to make the circuit use a moving dot display instead of a bar graph display.


Tuesday, November 29, 2011

AT89s51-52 and AVR USB Downloader

Microcontroller T89s51, AT89S52 and AVR is an idol among students. Well now because of technology trends and laptop PCs already left the LPT and COM so more and more difficult to download the firmware into the microcontroller, via LPT or COM. Solutions to be overcome with AT89S S-series, because the facility program downloads with the ISP (MISO, MOSI, SCK, RST), then use the ISP downloader which is also commonly used for this AVR microcontroller type. Time to play man with AT89s so much easier via USB without hassle and unplug the IC.
AT89s51-52 and AVR
USB Downloader Circuit

After you finish creating the PCB from the circuit above, then fill it to the ATmega8 with firmware usb51.hex do not forget to set low fuse = EF (SUT0 = 0, others = 1) and high fuse = C9 (SPIEN = 0, CKOPT = 0, BOOTSZ1 = 0, BOOTSZ0 = 0, others = 1). Of course, charging into the ATmega8, firmware downloader tool is needed.

For those who need a filling firmware and more complete information about the USB Downloader please visit


Wednesday, November 16, 2011

Rangkaian Pendeteksi Angin

This circuit uses an incandescent lamp to detect airflow (mendeteksi angin). With the filament exposed to air, a constant current source is used to slightly heat the filament. As it is heated, the resistance increases. As air flows over the filament it cools down, thus lowering it's resistance. A comparator is used to detect this difference and light an LED. With a few changes, the circuit can be connected to a meter or ADC to provide an estimation on the amount of air flow. 
Rangkaian Pendeteksi Angin
LM339 Pinout
The glass will have to be removed from L1 without breaking the filament. Wrap the glass in masking tape and it in a vise. Slowly crank down until the glass breaks, then remove the bulb and carefully peel back the tape. If the filament has broken, you will need another lamp.

List Component
R1   : 100 Ohm 1/4W Resistor 
R2   : 470 Ohm 1/4W Resistor 
R3   : 10k 1/4W Resistor 
R4   : 100K 1/4W Resistor 
R5   : 1K 1/4W Resistor 
C1   : 47uF Electrolytic Capacitor 
U1   : 78L05 Voltage Regulator 
U2   : LM339 Op Amp 
L1   : #47 Incandescent lamp with glass removed (See "Notes") 
D1   : LED 


Stepper Motor Controller using IC 4027

The stepper controller circuit is very interesting, since most lines the step motor controllers are very expensive. The circuit is made ​​of standard components and can easily be adjusted by a computer. If you cheap surplus transistors and stepper motors, the price of the circuit can be less than $ 15.
Stepper Motor Controller Circuit using IC 4027
This stepper controller circuit shown here can used to control the unipolar stepper motor, the which has four coils. The stepper controller circuit can drive for a motor current of up to about 500 MAMP / Winding by Suitable heat sinks for the SL-100 In higher currents seem 2N3055 power transistors can be used as darlington pair along with the SL-100. All diodes are used to protect the transistor from back current transients.

List Componet
R1, R2 ,R3, R4: 1K 1/4W Resistor
D1, D2, D3, D4: 1N4002 Silicon Diode
Q1, Q2, Q3, Q4: TIP31 NPN Transistor (See Notes) TIP41, 2N3055
U1            : 4070 CMOS XOR
U2            : 4027 CMOS JK Flip-Flop
S1            : SPDT Switch
1. You should be able to substitute any standard (2N3055, etc.) power transistor for Q1-Q4.
2. Every time the STEP line is pulsed, the motor moves one step.
3. S1 changes the motors direction.
4027 CMOS JK Flip-Flop IC  Pinout
4070 CMOS XOR IC Pinout

Skema Rangkaian Elektronika