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Light Laser LED
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Data Bus Circuits
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RF Converter Circuits
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8051 / 8052
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555 Timer Circuits
Remote Control Toy
H Bridge Circuit
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
New Circuits Page 9
Overheat Detector Alarm/Switch
At the heart of this circuit is a precision integrated temperature sensor type LM35 (IC1), which provides an accurately linear and directly proportional o..
Wireless Headphones Transmitter Circuit
This wireless headphones transmitter assures a quality reception over 2 meters. The oscillator frequency is between 1750KHz and 3500KHz and for antenna we..
A Tan Timer Circuit
This timer was designed for people wanting to get tanned but at the same time wishing to avoid an excessive exposure to sunlight. A Rotary Switch sets the timer according to six classified Photo-types (see table). A Photo resistor extends the preset time value according to sunlight brightness (see table). When preset time ends, the beeper emits...
A low-cost configurability test strategy for an embedded analog circuit
Nokia 6500 Camera Problem Picture Help
Nokia 6500 camera problem like camera operation failed or camera blank, can be solved by doing a little trick. The pictures below relating to Nokia 6500 slide camera problem, try to make a jumper like shown by the picture. The picture also show you the IC that related to camera circuit, replace that IC or try to reheat might be can solve your pro
DOD Phasor 595
protection against reverse voltage. The 10mfd provides additional DC filtering. The CD4007 is configured as a flip-flop( )controlled by the foot switch. The output of the flip-flop drives the indicator The 18v appears to go through a 100k resistor, then to each of the non-inverting inputs and associated resistor of each opamp, with the exception o
There are 3 basic types of earphones, each with their set of benefits and problems. Small transducers that are inserted into the auditory canal. This leaves only a few millimeters of a mismatched acoustic transmission line between the vibrating diaphragm of the transducer and the eardrum. This cavity should be sealed or have very slow air...
octopus curve tracer
This project involves the construction of a low-cost curve tracer that is suitable for testing a wide variety of electronic components both in-circuit and out of circuit. It is easy to construct and extremely useful for finding defective parts, especially semiconductors, in electronic devices. The octopus is used in conjuction with an oscilloscope
Oscillator circuit schematic
This web page describes the radio transmitter unit that flew aboard the Cirrus One rocket in April 2001. The intent of including the transmitter as payload was to: As the Cirrus One rocket was expected to achieve an altitude that would be well out of visual range at 10, 000 feet (3 km. ), it was felt that there could be recovery difficulties if the
Electronic Canary circuit
Feeling chirpy? Attract new friends with this modified hartley oscillator. You could also use it as a replacement doorbell..
Over-Temperature Alarm Circuit Uses Common Inexpensive Components
Over-Temperature Alarm Circuit Uses Common, Inexpensive Components | Negative-temperature-coefficient (NTC) thermistor, ICs.
An Add-On Current Limiter For Your PSU circuit
This circuit allows you to set a limit on the maximum output current available from your PSU. It`s very useful when you power-up a project for the first time - or carry out a soak-test. By setting an upper limit on the current available from your PSU - you can protect both your power supply - and any device connected to it. It offers a simple and
PJRC MP3 Player Schematic Diagrams
The two unspecified polarized capacitors (one directly above the transformer and one directly to the right of the transformer) are actually each a pair of 470 µF capacitors in parallel (for a total of four 470 µF capacitors). These capacitors MUST be Low-ESR types for the power supply to function properly. Figure 4: The two 100 µF 16V
can someone explain how circuit demodulates
Circuit Envelope Simulation Schematic of the PLL
radio transmitter circuit
Battery charging indicator circuit
This simple circuit can be used to monitor whether a battery is charging or not. The voltage comparator IC LM393 is the heart of this circuit. The LED D1 will remain ON whenever there is at least 25 milli ampere current flowing to the battery. This particular circuit is designed for a 12V battery with charging current less than 1A. By slightly modi
Signal conditioning circuits
Sawtooth Wave Generator
Sawtooth wave generator using NE555 and opamp uA741. NE555 is wired as square wave generator and opamp is wired as integrator.Circuit diagra, and working theory..
The Demodulating Receiver (A3017) contains a 902 ’930 MHz 30-dB amplifier, a downshifer, a 60-dB 50-MHz limiting IF amplifier, a frequency discriminator, and an amplitude demodulator. The A301701A circuit board also includes, just for good measure, more copies of the A3016SO SAW Oscillator and the A3008C Spectrometer. If you can`t understand our
Turbo Bass (Booster)
This is a Turbo Bass circuit. Using this circuit, the low frequency sound signals(bass) can be multiplied. This circuit is an active circuit. The first op-amp..
A Center tap 50Hz Step Down Transformer with two diodes is used to get a train of Positive Sine Pulses at 100Hz which is applied to Q6 base via R51. 2N2646 is a unijunction transistor(UJT) in a TO-18 metal package. The control voltage or voltage proportional to error is fed to R56-Q3, The UJT drives a pulse transformer which provides isolation fro
laptop schematic diagram
Laptop schematic diagram volvi blog diagram, DDR1 DDR2, Mobile cpu 478 celeron, ICH7M, audio circuit using G1431Q, Codec ALC268, opamp G1412, Modem MDC Card, HDD in, mini usb, Blue tooth, cdrom, Bios, camera..
AM Radio Oscillator Driver
Door handle alarm
The automatic door handle alarm circuit gives a audible alarm and glows a LED when somebody touches the handle of the door. The circuit is latching type and continues to produce sound until it is switched off. The transistor Q1 is wired as an astable multivibrator whose output is used to bias transistor Q2 to conduction. As a result the...
60W Guitar Amplifier
This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively high power outputs, and a certain built-in degree of loudspeaker protection, due to capacitor
solid state tesla coil circuit
Similar to the two transistor solid state Tesla Coil already on this site, this solid state Tesla Coil design uses a normal flyback transformer to generate it`s high voltage output. Unlike the other circuit, this one does not use two huge power transistors and high wattage resistors. Instead it uses a 555 timer to more efficiently drive a single M
AC lights dimmer with triac
This circuit has can to turn down a light bulb arrives at 100W. If Triac there is tall temperature should hold Heat Sink or let off the heat. The Diac be diode that perform be formed encourage or Trigger Diode 2 kinds are way or Bidirectional. The VR1 use for fine decorate turning down fire. Caution this circuit must is in a box closes all the tim
Pre Amplifier with low impedance input
Frequency to Voltage converter circuit based on the TC9400 IC
A simple frequency to voltage converter circuit designed around the TC9400 F to V / V to F converter IC. Dual and single supply versions are given here..
Code Practice Oscillator Using 555 Timer
This simple code practice oscillator project for beginners to Continuous Wave Morse Code uses a 555 timer to generate a dit or dah sound when the key is pressed
light up pumpkin
The concept is that a pair of yellow LEDs are placed in an otherwise inconspicuous pumpkin, and a photo sensor allows the circuit to turn on the lights at night. The circuit itself is very straightforward, incorporating minimal components. There are two schematics listed on the project site, but we suggest using the one above with an adjustment...
DX audio filter circuit
testing troubleshooting inverter
Just connect 22k fixed resistors across each transistor base and ground and then you may connect the 50K Dual pot leads across these resistors, that should imitate a 10k pot variations quite closely. Hi Swagatam, so just to be clear, you want me to remove the 10K resistors connected to the Base of each Transistor and replace with 22K resistors...
Automatic Light Controller Using 7806 circuit
Voltage regulator ICs (78xx series) provide a steady output voltage, as against a widely fluctuating input supply, when the common terminal is grounded. Any voltage about zero volt (ground) connected in the common terminal is added to the output voltage. That means the increase in the common terminal voltage is reflected at the output. On the...
Build a Variable-Frequency Audio Band pass FilterCircuit
This variable-frequency, audio bandpass filter is built around two 741 op amps that are connected in cascade. Two 741 op amps are configured as identical RC active filters and are connected in cascade for better selectivity. The filter`s tuning range is from 500~Hz to 1500 Hz. The overall voltage gain is slightly greater than 1 and the filter`s is
EMEM2 and EMEM3D frequency device construction and operation
The EMEM2 was invented by Dan Tracy. In a conversation with "Doug", the inventor of the large coil device, he commented that the EMEM2 does kill Lyme disease and that it is a lot of machine for the money. It has also been demonstrated to be useful for many other conditions. This version uses 6 pots to give a frequency range of about 7Hz to 10KHz a
Boosters Are Not Buffers
Boosters are not buffers! While it is possible to make a booster that also provides a buffering action, the vast majority of the boosters commercially available ready-made or kits, do not have the proper design to be buffers. A buffer should have a high input impedance (Z) and a low output impedance. The LPB1, shown at the top of this post, has a
frequency doubler with 4011
This frequency doubler uses one CMOS quad, two input NAND gate package type 4011. The frequency doubler proper consists of an inverter IC1B, two differentiating networks R1/C1, R2/C2 and NAND gate IC1A, IC1C and IC1D function as input and output buffers. In Fig. 2 exist the pulses in different points of circuit.
6A regulated variable powersupply
The following diagram is the schematic diagram of variable power supply which will deliver 0 to 28V output voltage at 6/8 A electric current. Component Part List: R1 = 2K2 Ohm 2, 5 Watt R2 = 240 Ohm R3, R4 = 0. 1 Ohm 10 Watt R7 = 6K8 Ohm R8 = 10K Ohm R9 = 47 Ohm. This is an adjustable power supply which have adjustabled output voltage from 6-12...
Simple B+ delay circuit for tube power amp
There is a mod to the RC delay circuits some of you may want to consider. If you wish to have a shorter discharge time so that the circuit restarts..
Lm3915 Audio Power Level Meter Circuit Design Electronic Project
Knightrider lights for model cars circuit
This simple circuit drives 6 LEDs in `Knightrider scanner mode`. Power consumption depends mainly on the type of LEDs used if you use a 7555 (555 CMOS version)..
AVR to LCD
If you can`t see any characters displayed on the LCD (and you`ve checked that the hardware and software are working) turn the LCD Contrast pot until you can see the characters. To load an 8 bit character or LCD command into the 74HC164 shift register, the code shifts the byte out bit by bit through PORTB bit 6, (LCDDat) clocking the 74HC164...
300Watt Inverter DC 24V to AC 220V
12v to 220v inverter circuit diagram, 24v inverter circuit, 24v to 220v inverter, 24vdc to 220vdc, 300w inverter, 300w inverter circuit diagram, Inverter, inverter 24v to 220v, inverter circuit, inverter dc to ac, power electronic
LED Light Pen
Physicians and repair engineers often use small light pens for visual examination Spurposes. Rugged and expensive as these pens may be, their weak point is the bulb, which is a serviceable` part. In practice, that nearly always equates to expensive` and / or impossible to find` when you need one. LEDs have a much longer life than bulbs and the lat
how to assemble radio transmitter
Metal detector circuit diagram 3
The metal detector is composed of the probe oscillator, reference oscillator and audio amplifier and other components, and the circuit is shown as the chart. Probe oscillator consists of transistors VI, V2 and detection coil L1, capacitor C1 and so on. Reference oscillator consists of transistors VI, Y3 and inductor L2, capacitor C3 and other comp
Hi, I am trying to use a Panasonic microwave inverter for a project I am experimenting with. I have limited knowledge with electronics but I can work..
hp max2338 mixer if saw filter match at 183 6mhz for cdma
183. 6MHz SAW filter in a CDMA application. The SAW filter S-parameter is used to simulate the interface with the mixer. A worked example is provided with a SAWTEK 855893 SAW filter. An optimum impedance matching circuit between the MAX2338 mixer differential IF ports and a 183. 6MHz CDMA IF SAW filter is presented in this application note. A...
Constant Current Constant Voltage Switching Power Supply
This is a circuit that produces constant current constant voltage SMPS. To efficiently charge a battery, we can use constant current constant voltage SMPS..
Triple LED has only 4 terminals
CV/CC charger circuit diagram designed using LinKSwitch
A very simple 3. 25W CV/CC charger can be designed using LinKSwitch | family IC manufactured by Power Integrations. This electronic circuit project is designed to provide a 5 volts output at a maximum current of 650mA. This 3. 25W CV/CC charger, needs to be powered using a AC voltage between 85 and 265 VAC. The AC input power is rectified by dio
Lithium Ion Charger 2 Cell
The charger operates by supplying a short current pulse through a series resistor and then monitoring the battery voltage to determine if another pulse is required. The current can be adjusted by changing the series resistor or adjusting the input voltage. When the battery is low, the current pulses are spaced close together so that a somewhat con
water level indicator controller pic
stepper motor interfacing with avr slicker
Electrical Isolation For I2C Bus
When the SDA (Serial DAta) lines on both the left and right lines are 1, the circuit is quiescent and optoisolators IC1 and IC2 are not actuated. When the..
MC2833 FM transmitter circuit design electronic project
A very simple FM transmitter circuit can be designed using MC2833 integrated circuit, designed for cordless telephone and FM communication equipment. It includes a microphone amplifier, voltage controlled oscillator and two auxiliary transistors. The final output frequency is generated by frequency multiplication within the MC2833 IC. The RF outpu
1996 Suzuki Esteem Cooling Fan Circuit Diagram
555 timer IC
The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation and oscillator applications. The part is still in widespread use, thanks to its ease of use, low price and good stability. As of 2003 [update], it is estimated that 1 billion units are manufactured every year.  The IC design was proposed in 1970 by H
Transmit Infrared Signals Through Walls
How to use your existing infrared transmitter from any room in the house. The principal is really pretty simple, and it works better than you would think. This is a "very handy" little project. With this gadget you can control anything from pretty much anywhere. Even place your stereo equipment inside an enclosure then use your existing IR...
Flyback Transformer Driver
an efficient flyback driver for modern cylindrical rectified television flybacks. Many sites doesn`t provide circuits driving these transformers, they simply say that they are bad. I don`t agree. In fact I built this circuit. I spent a lot of time for finding resonant frequency (around 15Khz) and duty cycle. These transformers best work at
Hi Fi Stereo Preamp Circuit
The first half of the circuit (IC1a) it has an input sensitivity of 3 mV and has a frequency correction composed of C5, C3, R6 and R8. The bass signal coming from phono input is amplified while the high signal is attenuated. The selection of the input signal sources is done with switch S1. P1 and P2 are parte of a double potentiometer. They contro
The circuit in the diagram is a very handy tool for rapidly checking all kinds of thyristor (SCR, triac, ). In case of a triac, all four quadrants are te..
Lighting designs with flicker-free LED dimming
LED lighting, and the potential that it brings, is moving to the forefront of residential and commercial lighting markets. However, to maximize the success and adoption of solid-state lighting for retrofit lamps, the LED lamps should be capable of dimming when used with existing controllers and wiring. Attempts to dim LED lamps have encountered a
This is a simple form circuit for a 2-station intercom using common 8R mini speakers. The press-to-talk switches should have a spring-return so the intercom can never be left ON. This is the figure of the circuit; Power the speaker from a separate power supply is the secret to preventing instability (motor-boating) with a high gain circuit like
800w schematic diagram of 800 watt audio amplifier with mosfet
lm358 ic and schematic diagram
MEMS based oscillator for UHF applications with automatic amplitude control
geiger power supply circuit
This is a step by step guide to modifying the disposable camera flash unit that powers the Geiger tube in the last post. Geiger tube power supply hack using disposable camera flash unit Remove the flash tube and trigger transformer from the circuit board this can be done by gently squeezing the reflector assembly then pushing it carefully out of t
12v Battery Charger Circuit with Auto Cut off
This is a simple DIY charge controller schematic posted in response to a request by one of our readerson our facebook page. The main component of this auto battery charger circuit is a 555 timer which compares the voltage in the battery. It turns ON the charger if the battery voltage is below the variable preset voltage (12 volt chosen here) and
sound simple audio amplifier
The quality sound was terrible, and suddenly it stoped working. Can anyone explain me in which part of the circuit i did something wrong any sugestions to improve the sound quality and make it work the transistors used are both BC546, and the microphone was acctually an input for an mp3 player, but i didn`t found in the programam that i did the...
Audio Amplifiers 8
a year ago I designed a class-D amplifier based on the TAS5162, pcm1808 and TAS5086. During the year, was made a few hundred samples intended to be sold to radio amateurs. Most devices are functioning properly and not cause any complaints from consumers. But some instances do not work properly. in some cases, users complain about the failure of
10A adjustable voltage regulator using MSK5012
Reliable 10A adjustable voltage regulator based on MSK5012. 1.3 to 30V output voltage range. Low ripple and high efficiency..
Wireless FM Transmitter
Wireless FM Transmitter. The photo shows a wireless FM transmitter, pocket radio and yellow disk for size comparisons. Speak into the transmitter and others hear you on any FM.
More LED Flashers
a better sine wave
This one is actually a bit simpler to explain: the op-amp is set up with 25. 50x amplification, i. e almost a comparator (with 50x amplification, a 50 mV input above or below the 2. 5V will drive the output to its limit). And indeed, the output signal of the op-amp looks somewhat like a heavily clipped sine wave: The 3 resistors and 3 capacitors...
Run/Stop Relay Circuit
Safety is a major concern in a good many motor-driven applications. This is true in industrial applications where motion starts when power is applied and e..
AM radio circuit based on TDA1572. 9V operation2W output
High quality AM radio circuit based on TDA1572 IC. The AM radio receiver circuit operates from 9V DC and has 1W output power. Requires minimum external components..
pulse width to voltage converter