Wiring panel: August 2013

Saturday, August 31, 2013

Pulse Timer Control Relay Circuit with IC555

Today we would like to offers solutions for a set time for take control relay and take NO. / NC. contact to apply to control other devices . such as disable or enable the device.function of this circuit is using IC555 to determine the pulse and a resistor R1 to the period of time.

Pulse Timer Control Relay Circuit Diagram

R1       #Seconds
100k         2
220k         3
470k         6
1M           15

The increase provides more time to increase the value of the Capacitor.

Part List
R1 = 1 Meg, Preset Pot
R2 = 10K
R3,R4 = 1K
C1 = 10uF, 16V
C2 = 0.01uF
T1 = BC547 (Gen Purp NPN)
T2 = 2N2222 (Hi Current NPN)
D1 = 1N4001 (Gen Purp Si)
IC1 = 555 (Lo-Power version)
RLA1 = Relay, 9V (amps of your choice)

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Thursday, August 15, 2013

Two Basic Motor Speed Controllers

Here are two simple 12V DC motor speed controllers that can be built for just a few dollars. They exploit the fact that the rotational speed of a DC motor is directly proportional to the mean value of its supply voltage. The first circuit shows how variable voltage speed control can be obtained via a potentiometer (VR1) and compound emitter follower (Q1 & Q2). With this arrangement, the motor’s DC voltage can be varied from 0V to about 12V. This type of circuit gives good speed control and self-regulation at medium to high speeds but very poor low-speed control and slow starts. The second circuit uses a switchmode technique to vary motor speed.

Circuit diagram:

Fig.1: a very simple motor speed controller based on a compound emitter follower (Q1 & Q2).

Here a quad NOR gate (IC1) acts as a 50Hz astable multivibrator that generates a rectangular output. The mark-space ratio of the rectangular waveform is fully variable from 20:1 to 1:20 via potentiometer VR1. The output from the multivibrator drives the base of Q1, which in turn drives Q2 and the motor. The motor’s mean supply voltage (integrated over a 50Hz period) is thus fully variable with VR1 but is applied in the form of high-energy "pulses" with peak values of about 12V.

Circuit diagram:

Fig.2: this slightly more complicated circuit gives better low speed control and higher torque.

This type of circuit gives excellent full-range speed control and gives high motor torque, even at very low speeds. Its degree of speed self-regulation is proportional to the mean value of the applied voltage. Note that for most applications, the power transistor (Q2) in both circuits will need to be mounted on an appropriate heatsink.

Source by : Streampowers

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Wednesday, August 14, 2013

Comparator Based Crystal Oscillator

Although a simple crystal oscillator may be built from one comparator of an LT1720/LT1721, this will suffer from a number of inherent shortcomings and design problems. Although the LT1720/LT1721 will give the correct logic output when one input is outside the common mode range, additional delays may occur when it is so operated, opening the possibility of spurious operating modes. Therefore, the DC bias voltages at the inputs have to be set near the center of the LT1720/LT1721’s common mode range and a resistor is required to attenuate the feedback to the non-inverting input. Unfortunately, although the output duty cycle for this circuit is roughly 50%, it is affected by resistor tolerances and, to a lesser extent, by comparator offsets and timings.

If a 50% duty cycle is required, the circuit shown here creates a pair of complementary outputs with a forced 50% duty cycle. Crystals are narrow-band elements, so the feedback to the non-inverting input is a ﬁltered analogue version of the square-wave output. The crystal’s path provides resonant positive feedback and stable oscillation occurs. Changing the non-inverting reference level can vary the duty cycle. The 2k-680Ω resistor pair sets a bias point at the comparator + (Comparator IC1a) and – (Comparator IC1b) input. At the complementary input of each comparator, the 2k-1.8k-0.1µF path sets up an appropriate DC average level based on the output.

IC1b creates a complementary output to IC1a by comparing the same two nodes with the opposite input. IC2 compares band-limited versions of the outputs and biases IC1a’s negative input. IC1a’s only degree of freedom to respond is variation of pulse width; hence the outputs are forced to 50% duty cycle. The circuit operates from 2.7V to 6V. When ‘scoping the oscillator output signal, a slight dependence on comparator loading, will be noted, so equal and resistive loading should be used in critical applications. The circuit works well because of the two matched delays and rail-to-rail outputs of the LT1720.

Source by : Streampowers

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Tuesday, August 13, 2013

Police Lights associate crystal rectifier Project

This circuit uses a 555 timer that is setup to each runn in associate Astable operative mode. This generates a nonstop output via Pin three within the type of a sq. wave. once the timers output changes to a high state this triggers the a cycle the 4017 4017 decade counter telling it to output consecutive sequent output high. The outputs of the 4017 ar connected to the LEDs turning them on and off.

Schematic
Police Lights and LED Project

Parts List

1x - NE555 Bipolar Timer
1x - 4017 Decoded Decade
6x - 1N4148 Diode
1x - 1K Resistor (1/4W)
1x - 22K Resistor (1/4W)
2x - 4.7K Resistor (1/4W)
6x - 470 Resistor (1/4W)
1x - 2.2µF Electrolytic Capacitor (16V)
2x - BC547 NPN Transistor
2x - LED (Blue)
2x - LED (Red)
1x - 9V Voltage Battery Link

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Sunday, August 11, 2013

Power Mosfet Inverter Circuit Diagram

This Power Mosfet Inverter Circuit Diagram can deliver .high-voltage ac or dc, with a rectifier and filter, up to several hundred volts. The secondary and primary of T1-a 12.6 to 440 V power transformer, respectively-are reversed; e.g., the primary becomes the secondary and the secondary becomes the primary. Transistors Q1 and Q2 can be any power FET. Be sure to heat sink Q1 and Q2. Capacitors C1 and C2 are used as spike suppressors.

Power Mosfet Inverter Circuit Diagram

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Saturday, August 10, 2013

3000W Stereo Power Amplifier Circuit

Circuit Power Amplifier has a power output of up to 1500W RMS power amplifier circuit is often used to power sound systems keperlun for outdor. In the final image can be seen a series of power amplifiers using 10 sets of power transistors for the ending.

This power amplifier circuit using a transistor amplifier from the front, signal splitter, driver and power amplifier. Current consumption required is quite large power amplifier that is 15-20 A 1500W power amplifier circuits for this. Supply voltage needed by the power of this amplifier is the optimal working order symmetrical 130VDC (130VDC-130VDC ground). 1500W amplifier circuit below is a picture series of mono, stereo if you want to make it necessary to make two copies of the circuit. For more details can be viewed directly image the following 1500W power amplifier circuit.

The series of High Power Amplifier 1500W With Transistor

Click Image to view larger

In the above series of power amplifer 1500W is equipped to control a DC Offset function to set the power amplifier is turned on at the moment and with no input signal then the output should be 0VDC. Then also equipped with a flow regulator to the power amplifier bias. Final part of this power amplifier requires adequate cooling to absorb the heat generated. Power amplifier is not equipped with a speaker protector, therefore it is necessary diapsang protector on the speaker output so that when the power amplifier is not the case turned on the beat to the speaker that can damage the speaker.

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Friday, August 9, 2013

All Constructing Various DC Power Supplies Projects

One of the fundamental building blocks of electronics challenge is building your personal DC energy supplies from an AC source of one hundred ten V.A.C or 220 V.A.C.The fashionable DC voltages which are essential to energy up the devices are frequently within the vary of three V DC to 30 V DC. Usually the fixed types of DC voltages are 5V, 9V, 12V, 15V & 18V DC. With the development of know-how, plenty of instruments are the use of one.8 V DC nowadays. S M P S is turning into in style this existing day because the demand for miniaturization due to area constraints will increase.

Take note that for linear energy supply projects, you wish to make use of a step down power transformer to step down the AC voltage from the road voltage of 110 V.A.C or 220 V.A.C ahead of the usage of it to produce to the diode bridge.

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Thursday, August 8, 2013

Long Interval Pulse Generator

A rectangular-wave pulse generator with an extremely long period can be built using only two components: a National Semiconductor LM3710 supervisor IC and a 100-nF capacitor to eliminate noise spikes. This circuit utilises the watchdog and reset timers in the LM3710. The watchdog timer is reset when an edge appears on the WDI input (pin 4). If WDI is continuously held at ground level, there are not any edges and the watchdog times out. After an interval TB, it triggers a reset pulse with a duration TA and is reloaded with its initial value. The cycle then starts all over again. As a result, pulses with a period of TA + TB are present at the RESET output (pin 10).

Long-Interval Pulse Generator Circuit diagram :

As can be seen from the table, periods ranging up to around 30 seconds can be achieved in this manner. The two intervals TA and TB are determined by internal timers in the IC, which is available in various versions with four different ranges for each timer. To obtain the desired period, you must order the appropriate version of the LM3710. The type designation is decoded in the accompanying table. The reset threshold voltage is irrelevant for this particular application of the LM3710. The versions shown in bold face were available at the time of printing. Current information can be found on the manufacturer’s home page (www.national.com). The numbers in brackets indicate the minimum and maximum values of intervals TA and TB for which the LM3710 is tested. The circuit operates with a supply voltage in the range of 3–5 V.

Source : http://www.ecircuitslab.com/2011/06/long-interval-pulse-generator.html

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Tuesday, August 6, 2013

Cell Phone Jammer Circuit Diagram

Circuit showing a mobile phone jammer. A beautiful diy gsm jammer or mobile cell phone jammer schematic diagram for use only in GSM1900 with frequency from 1930 MHz to 1990 MHz. The GSM1900 mobile phone network is used by USA, Canada and most of the countries in South America.

This cell phone jammer is not applicable for use in Europe, Middle East, nor Asia. The GSM jammer circuit could block mobile phone signals which works on GSM1900 band, also called DCS. For more cell phone jammers check the related posts.

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Monday, August 5, 2013

230V Blinking LED

Already I have posted 230V LED circuit diagrams.This circuit is different than those circuits.Because this circuit is blinking circuit.And here I have used common parts so you all can find them easily.Already I have attached this circuit with our doorbell switch then the visitors who visit my place at night can see it well.

Note:-

# When you deal with 230V be careful because it is dangerous
# Fix this circuit in a plastic box

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Sunday, August 4, 2013

Transformerless Power Supply Circuit

This circuit will supply up to about 20ma at 12 volts. It uses capacitive reactance instead of resistance; and it doesnt generate very much heat.The circuit draws about 30ma AC. Always use a fuse and/or a fusible resistor to be on the safe side. The values given are only a guide. There should be more than enough power available for timers, light operated switches, temperature controllers etc, provided that you use an optical isolator as your circuits output device. (E.g. MOC 3010/3020) If a relay is unavoidable, use one with a mains voltage coil and switch the coil using the optical isolator.C1 should be of the suppressor type; made to be connected directly across the incoming Mains Supply.

They are generally covered with the logos of several different Safety Standards Authorities. If you need more current, use a larger value capacitor; or put two in parallel; but be careful of what you are doing to the Watts. The low voltage AC is supplied by ZD1 and ZD2. The bridge rectifier can be any of the small Round, In-line, or DIL types; or you could use four separate diodes. If you want to, you can replace R2 and ZD3 with a 78 Series regulator. The full sized ones will work; but if space is tight, there are some small 100ma versions available in TO 92 type cases. They look like a BC 547. It is also worth noting that many small circuits will work with an unregulated supply.

Circuit diagram:

Transformerless Power Supply Circuit Diagram

You can, of course, alter any or all of the Zenner diodes in order to produce a different output voltage. As for the mains voltage, the suggestion regarding the 110v version is just that, a suggestion. I havent built it, so be prepared to experiment a little. I get a lot of emails asking if this power supply can be modified to provide currents of anything up to 50 amps. It cannot. The circuit was designed to provide a cheap compact power supply for Cmos logic circuits that require only a few milliamps. The logic circuits were then used to control mains equipment (fans, lights, heaters etc.) through an optically isolated triac.

If more than 20mA is required it is possible to increase C1 to 0.68uF or 1uF and thus obtain a current of up to about 40mA. But suppressor type capacitors are relatively big and more expensive than regular capacitors; and increasing the current means that higher wattage resistors and zener diodes are required. If you try to produce more than about 40mA the circuit will no longer be cheap and compact, and it simply makes more sense to use a transformer. The Transformerless Power Supply Support Material provides a complete circuit description including all the calculations.

Web-masters Note:

I have had several requests for a power supply project without using a power supply. This can save the expense of buying a transformer, but presents potentially lethal voltages at the output terminals. Under no circumstances should a beginner attempt to build such a project.

Important Notice:

Electric Shock Hazard. In the UK,the neutral wire is connected to earth at the power station. If you touch the "Live" wire, then depending on how well earthed you are, you form a conductive path between Live and Neutral. DO NOT TOUCH the output of this power supply. Whilst the output of this circuit sits innocently at 12V with respect to (wrt) the other terminal, it is also 12V above earth potential. Should a component fail then either terminal will become a potential shock hazard.

MAINS ELECTRICITY IS VERY DANGEROUS.

If you are not experienced in dealing with it, then leave this project alone. Although Mains equipment can itself consume a lot of current, the circuits we build to control it, usually only require a few milliamps. Yet the low voltage power supply is frequently the largest part of the construction and a sizeable portion of the cost.

Author: Ron J - Copyright: Zen

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Saturday, August 3, 2013

Telephone Line Monitor Circuit

This is a circuit that will find application in the case where you have a lot of telephones installed on a telephone line and would want to know if somebody of them is open. Thus you will not be off any discussion. Simultaneously it can cut the certain sound from stereo amplifier that are in high volume, the sound of some television or turn on some light the night when it ring the telephone and needs him you raise. Here’s the figure of the circuit;

Exists a pair of free contacts of RL1 that connects to the J2, which you can use connecting there any appliance you want. The telephone line connected in the J1, with what polarity you wants. When the telephone is closed then the line voltage is roughly, 48-50Vdc. This voltage turn on the photo diode and this, the transistor of IC1, which it simultaneously isolates, the circuit from the telephone line. The photo transistor in IC1 are now in situation ON, the input of IC2A are LOW [L] and output HIGH [H]. Ignoring for little the circuit of delay D6, R4, R5, C1, the IC2B input, are also this HIGH hence the output are LOW, transistor Q1 are OFF and the RL1 are deactivate. When the telephone earphone is raised, then the telephone voltage line fall in 6-10Vdc.

All the previous situation is reversed also the RL1, turn on. The telephones that use for dial choice, disk or pulse system, can they open and close the RL1 at the duration of choice. With delay network, that exist between in gates IC2A and in the IC2B, we delay the situation changes in the input of IC2B, ensuring thus stability in the operation of RL1. If the R4=100K then the RL1 is activated when the telephone ring or when the earphone is raised. On the contrary if the R4=1M, then the RL1 is activated only when the earphone is raised. The circuit supply becomes with a simple regulation circuit, in + 12V.

Part:

R1-2=36Kohm
R3=100Kohm
R4=100Kohm or 1Mohm
R5=2.2Mohm
R6=3.3Kohm
R7=1Kohm
D1....4=1N4002
D5=1N5252 [24V 0.5W Zener]
D6-7=1N4148
D8....11=1N4002
D12=Red Led 3 or 5mm
RL1=12Vdc 2X2 relay
J1-4=2pin connector 2.54mm step
J2=6pin connector 5mm step
J3=2pin connector 5mm step
F1=Fuse 500mA [5x20mm]
C1=100 or 220nF 100V MKT
C2=1000uF 25V
C3-4=100nF 100V
C5=4.7uF 16V
IC1=4N25 opto coupler
IC2=4011B
IC3=7812 [1A]
Q1=BD139 or BD679
T1=12Vac 500ma tranformer for pcb

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Thursday, August 1, 2013

Battery Powered High voltage Generator Circuit Diagram

This is the battery powered high-voltage generator circuit diagram. Output voltage great enough to jump a l-inch gap can be obtained from a 12-V power source. A 555 timer IC is connected as an stable multi vibrator that produces a narrow negative pulse at pin 3. The pulse turns Ql on for the duration of the time period. The collector of Ql is direct-coupled to tbe base of tbe power transistor Q2, turning it on during the same time period.

The emitter of Q2 is direct -coupled through current limiting resistor R5 to the base of the power transistor. Q3 switches on, producing a minimum resistance between the collector and emitter. The high-current pulse going through tbe primary of high-voltage transformer Tl generates a very high pulse voltage at its secondary output terminal (labeled X). The pulse frequency is determined by tbe values of Rl, R2, and C2. The values given in the parts list were chosen to give the best possible performance when an auto-ignition coil is used for Tl.

Battery Powered High-voltage Generator Circuit Diagram

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