Owner: Wiparat Circuit Electronics URL:http://www.wiparat.com/ Join Date: Sat, 06 Sep 2008 03:31:37 -0500 Rating:0 Site Description: Circuit blog such LED Flasher, Digital circuit, led display, Timer, Oscillator, Alarm, Battery, Meter, Switch Circuit Site statistics:Click here
Park-Aid with IC LM324,555,7812 2008-09-05 05:18:20 Three LEDs signal bumper-barrier distance
Infra-red operation, indoor use [....]
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PWM Speed Motor Controller By IC 555 2008-09-04 21:12:57 This 555 timer based PWM controller features almost 0..100% pulse width regulation using R1, while keeping the oscillator frequency relatively stable. The frequency is dependent on values of R1 and C1, values shown will give a frequency range from about 170 to 200 Hz. Any 555 chip will do, CMOS is fine as well. Diodes [...] Read more:Motor
, Speed
A low cost step-up converter by IC 555 2008-09-04 11:11:38 This is a power source that creates a DC voltage higher than the voltage feeding the it. It might be used to power your laptop (+18V) from a car battery (12V ~ 13.8V). It is built using very ordinary parts that should be readily available. [.....]
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by IC [...]
Inverts to Negative From Positive Voltage by IC 555 2008-09-04 11:07:26 This simple circuit is a good solution to the powering a dual supply op amp from a single battery problem. The circuit simply takes a positive voltage and inverts it. It uses only one 555 timer and a few other passive components, so it doesn’t add much in the way of size and cost to [...] Read more:Negative
, Positive
, Voltage
Inverter 12V to 220V 300W by NE555,2N3055 2008-09-04 11:03:18 Inverter 12V to 220V 300W by NE555,2N3055
This be inverter circuit the size about 300W .It performs to transform from battery 12V be house electric 220V 50Hz by have signal picture is Square wave. And it has the distinction that uses the equipment seek easy, such as integrated circuit NE555 and 2N3055 transistors. request to have [...]
Generating -5 Volts From a 9 Volt Battery With IC 555 2008-09-04 07:37:31 A 555 timer can be used to generate a squarewave to produce a negative voltage relative to the negative battery terminal. When the timer output at pin 3 goes positive, the series 22 uF capacitor charges through the diode (D1) to about 8 volts. When the output switches to ground, the 22 uF cap discharges [...]
35W Hi-Fi AUDIO POWER AMPLIFIER by TDA2050 2008-09-02 11:08:43 If you want to build hi-fi power amplifier the size about 30watt to 50Watt at good sound and build easy. I begs for to advise the circuit that builds with the integrated circuit. You wares IC TDA2050 then like very the circuit model class AB audio amplifier. [.....]
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DC to AC Inverter by IC 555 and TIP41, TIP42 2008-09-02 09:22:58 This be basic AC inverter Circuit. Convenient for the initiator who have to is extremely fond of something experience. Because of use IC 555 highly popular, perform produce the frequency ,then enlarge with transistor NPN and PNP number TIP41 and TIP42 drive the coil transformer. [.....]
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LED Chaser by IC 4017 + IC 555
Nite [...]
SW RF Pre-Amplifier 2008-10-11 10:12:53 Notes:
The problem with amplifying weak radio signals is that you also amplify the noise. What you can receive depends on how much background noise is present, whether it be man made interference or static. In this design the RF signal is first met by a resistive attenuator, this is necessary as strong signals could otherwise [...] Read more:Amplifier
Surveillance Transmitter Detector 2008-10-11 10:07:12 My site contains a few low power transmitters of one type or another, but until now no receiver. This circuit can be used to “sweep” an area or room and will indicate if a surveillance device is operative. The problem in making a suitable detector is to get its sensitivity just right; too much and [...] Read more:Detector
, Transmitter
2 Transistor Transmitter by 2N2222 2008-10-11 10:04:16 Transistor T1 works as an audio preamplifier, gain is fixed at approximately R2/R1 or 100 times. The audio input is applied at the points LF in (on the diagram). P1 works as gain control. After amplification this audio signal now modulates the transmitter built around T2. Frequency is tunable using the trimmer CT and L1 [...] Read more:Transmitter
Speed Control of 3-Phase Induction Motor Using PIC18 Microcontrollers 2008-10-11 09:54:31 Induction motors are the most widely used motors for appliances, industrial control, and automation; hence, they are often called the workhorse of the motion industry. They are robust, reliable, and durable. When power is supplied to an induction motor at the recommended specifications, it runs at its rated speed. However, many applications need variable speed [...] Read more:Control
, Induction
, Motor
, Speed
Servo Control of a DC Brush Motor 2008-10-11 09:51:10 The PIC17C42 microcontroller is an excellent choice for cost-effective servo control in embedded applications. Due to its Harvard architecture and RISC features, the PIC17C42 offers excellent computation speed needed for real-time closed loop servo control. This application note examines the use of the PIC17C42 as a DC brush motor servo controller. It is shown that [...] Read more:Brush
, Control
, Motor
500mW FM Transmitter by BC549 2008-10-10 10:57:15 The TX500 is a simple to build 500mW FM Transmitter
. It consists of three blocks; modulator / oscillator, two stage 500mW VHF amplifier and LED based power meter. The TX500 allows to transmit audio signals to FM band at frequencies from 88 MHz to 108 MHz. Due to the very low power consumption of less [...]
TX300 300mW FM Transmitter by BC549 2008-10-10 10:53:47 Here it is a brand new TX300 FM transmitter. The amplifier has exactly the same architecture as TX500 with the difference that TX300 has only one stage variable VHF amplifier. It is a cute schematic that was made for all of you who wanted something even simpler than TX500 and with not as many necessary [...] Read more:Transmitter
An AM RF Amp for External Antennas 2008-11-01 00:47:00 AM radio RF Amplifer
The first article had a 3PDT switch that not only acted as a power switch, but also allowed the user to bypass the amplifier. This would be very useful for areas with strong stations, to avoid overloading the receiver. The second article utilized a ferrite bar antenna, which severely compromised sensitivity. It [...] Read more:External
Broadcast-Band RF Amplifier using 2N3904 2008-11-01 00:39:58 The circuit can be wired up on a piece of perfboard; a PC board is not necessary, although one can be used. However you build the circuit, keep lead lengths short and direct, and separate the input and output stages. You may have to install the amplifier in your receiver. Otherwise, installing it in a [...] Read more:Amplifier
, Broadcast
500 Watt PA with PL519 2008-11-01 00:32:26 This is the circuit of a 500 watt linear amplifier, based upon a design by Frits Geerligs, PA0FRI, who has his own homepage at ~fhvgeerligs. The circuit uses four PL519 TV line output valves in a very simple circuit that will deliver over 450 watts at 3.5 MHz (350 watts at 30 MHz). PL519 (40KG6A) [...]
0-30 Volt 0-1Amp Laboratory Power Supply using 2N3055 2008-10-31 12:02:27 With reference to the schematic, lamp, LP2, is a power-on indicator. The other lamp (lower) lights when the unit reaches its preset current limit. R5, C2, and Q10 (TO-3 case) operate as a capacitor multiplier. The 36 volt zener across C2 limits the maximum supply voltage to the op-amps supply pins. D5, C4, C5, R15, [...] Read more:Laboratory
, Power Supply
, Supply
0-28V 6-8A Power Supply with LM317, 2N3055 2008-10-31 11:32:08 This is an easy to make power supply which has stable, clean and regulator 0-28V 6/8 Amp output voltage. By using two 2N3055 transistors we become more then 2 times the amount of amps then the power supply delivers, making it real though to brake ;). Although you could use this design to deliver 20 [...] Read more:Power Supply
, Supply
The Resistive Power Supply 2008-10-31 10:52:20 When designing a resistive power supply, the value of the “dropper resistor” is obtained by taking 12v from 240v = 230v. This is the voltage across the dropper resistor.
Let us allow 20mA current through the dropper resistor.
The value of the dropper resistor is: 230/0.02 = 11,500 ohms = 11k5.
The wattage of the resistor = 4.6watts [...] Read more:Power Supply
, Supply
A Capacitor-FED Power Supply 2008-10-31 10:49:47 Each 100n “X2″ capacitor (these are Mains rated capacitors) will deliver 7mA to each power supply (the 12v supply and the 5v supply). The only problem is the two supplies must be kept separate and no component can have a DC path from one supply to the other.
Each supply will deliver 21mA and obviously this [...] Read more:Supply
Constant Current Circuit with LM317 2008-10-31 10:40:49 If the constant-current circuit is not included, the current to the laser diode would drop as the battery voltage falls and the laser diode would cease to operate if the current falls below a certain minimum.
All “Laser Pointers” have an inbuilt constant current circuit to maintain the operation of the laser.
The output current in the [...] Read more:Circuit
, Constant
, Current
Laser Diode Supply with LM317 2008-10-31 10:35:38 The voltage between the output terminal and “adjust” is fixed a 1.2v (for this type of regulator). The 18R resistor in the circuit is called a voltage dropping resistor. It is designed to produce a voltage across it according to the current flowing. If it is 18R, the current flow will be: 1.2/18 = 66milliamps. [...] Read more:Laser
, Supply
A Negative Power Supply using IC 7905 2008-10-31 10:30:36 A negative power supply can be produced with a 7905 voltage regulator. Three things to be remembered are:
1. Check the connections of the 7905 before fitting it.
2. Reverse the 2200u and 10u electrolytics and LED.
3. Reverse the bridge so the negative goes to the “in” pin of the 7905.
Source Read more:Negative
, Supply
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