Showing posts with label for. Show all posts
Showing posts with label for. Show all posts
Tuesday, January 6, 2015
Power Supply for regulated current and voltage
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| Click to enlarge |
This is also another useful project for anyone working in electronics.
Both Current and Voltage Regulation is Extremely Important to Help Prevent Damage to Circuit, Especially Experimental Circuits.
This circuit used a Rotary Switch to select Various Current ranges as a Potentiometer is not very practical for the lower resistance/High Current Ranges.
Monday, November 3, 2014
Protection For Telephone Line Circuit
A long time ago when telephones were so simple almost nothing could go amiss from an electrical point of view, Telecom operators installed surge protection on all telephone lines exposed to storm risks. Paradoxically, now that we are hooking up delicate and expensive equipment such as telephones filled with electronics, fax machines, (A)DSL modems, etc., this protection has disappeared.
However, if you have the good fortune to live in the countryside in a building served by overhead telephone lines, there’s an obvious risk of very high voltages being induced on the lines during thunderstorms. While we have lost count today of all of the modems, fax machines and other telephones that have been destroyed by a ‘bolt of lightning’, surprisingly you only have to invest a few pounds to get a remarkably efficient protection device like the one we are proposing here.
During a storm, often with lightning striking near a telephone line, the line carries transient voltages up to several thousands of volts. Contrary to the HV section of television sets or electrical fences, on which practically no current is running, in the case of lighting striking current surges of thousand of amps are not uncommon. To protect oneself from such destructive pulses, traditional components are not powerful or fast enough.
As you can see on our drawing, a (gas-filled) spark gap should be used. Such a component contains three electrodes, insulated from each other, in an airtight cylinder filled with rare gas. As long as the voltage present between the electrodes is below a certain threshold, the spark gap remains perfectly passive and presents an impedance of several hundreds of MW. On the other hand, when the voltage rises above this threshold, the gas is very rapidly ionized and the spark-gap suddenly becomes a full conductor to the point of being able to absorb colossal currents without being destroyed.
Protection Circuit Diagram For Telephone Line :
The one we are using here, whose size is of the same magnitude as an ordinary one watt resistor, can absorb a standardized 5,000 amps pulse lasting 8/20 ms! Since we are utilizing a three-electrode spark gap, the voltage between the two wires of the line or between any wire and ground, cannot exceed the sparking voltage, which is about 250 volts here. Such protection could theoretically suffice but we preferred to add a second security device made with a VDR (GeMOV or SiOV depending on the manufacturer), which also limits the voltage between line wires to a maximum of 250 volts.
Even if this value seems high to you, we should remember that all of the authorized telephone equipment, carrying the CE mark must be able to withstand it without damage. This is not always the case however with some low-end devices made in China, but that’s an entirely different problem. Since pulses generated by lightning are very brief, the ground connection of our assembly must be as low-inductance as possible.
It must therefore be short, and composed of heavy-duty wire (1.5 mm2 c.s.a. is the minimum). If not, the coil, composed of the ground connection, blocks the high frequency signal that constitutes the pulse and reduces the assembly’s effectiveness to nothing. Finally, please note that this device obviously has no effect on the low frequency signals of telephones and fax machines and it does not disturb (A)DSL signals either.
Monday, October 13, 2014
Akrapovic Twin Exhaust System Schematic Diagram for 2009 SUZUKI GSX R 1000
Akrapovic Racing and Evolution systems are designed for riders who demand maximum performance from their motorcycle. Both systems are significantly lighter if compared to stock exhaust system and feature exceptional production quality, hi-tech materials and of course increased engine performance combined with pure racing sound output. 
The following file contains detail description and explanation on Akrapovic Twin Exhaust System for 2009 SUZUKI GSX-R 1000 and its schematic diagram. The system’s effect on the torque and power curve is huge and strongest in midrange rpm.
Get more info on Akrapovic Twin Exhaust System Schematic Diagram for 2009 SUZUKI GSX-R 1000 here
Wednesday, October 1, 2014
High Low Voltage Protector Circuit for Refrigerator with Timer
Back up power supply can be provided to the timer circuit to maintain time cycles during power failure as shown in Fig. 2. , By using different outputs (Q0 t to Q9, not shown) of IC 4017 or IC 0 4060, the timer can be utilised for purposes such as delayed and precise switching.
Thursday, September 25, 2014
Power Back up Circuit for CMOS ICs
Even very brief mains power failures cause problems for electronic circuits. Stored data are lost and the operating statuses are no longer what they were before the power failure.
Mains power failures cannot be prevented, but methods can be employed to provide a voltage backup for the duration of the fault. For this reason, mains-powered equipment is often fitted with backup batteries (nicad or lithium cells) to maintain operation during a mains power failure. In view of the low currents (microamperes) required for data storage with modern Fl/-lVls, there ls·~ an alternative backup method which is well worth consider- ing: power backup with an electro- lytic capacitor for energy storage! The circuit diagram Tshcvvs .just such an application. The power standby’ capacitor C1 is 4700 ;,iF and with a maximum load current of 10;;/~, the discharge time at an output voltage of 5 V is approxi- mately 53 minutes. The operating voltage of the circuit itself is 15 V, 10 V higher than the output voltage. As long as the 15 V supply voltage ls applied, capacitor C1 charges up to the value of the operating voltage via diode D1. Simultaneously, a bias voltage of approximately 2.3 V is applied to the gate of field effect transistor T1 via voltage divider R1/R2. This ensures that T1 is turned on and capacitor C2 is charged up.
The output voltage at the source t iinal r~· th e second field effect transistor remains a constant 5 V. The two FETs can be thought of as a voltage divider. lf the supply voltage fails, electro- lytic capacitor C1 will become the temporary power supply. Since the gate voltage is removed from T1 it turns off. Capacitor C2 is no longer being charged. However, it‘can only discharge very slowly because T2 has a very high input resistance. The voltage across C2 remains almost constant. Capacitor C1 supplies the operating voltage required for T2 so that it conducts and maintains the output voltage at 5 V. Capacitor Cl discharges very slowly, as a function of its insulation resistance (R|N3 approximately 1 l/ll and the load current flowing. The output voltage at the source lead of T2 remains a constant 5 V, until the voltage across C1 has also dropped to 5 V. lf this voltage drops even further, FET T2 remains turned on but the output voltage decreases proportionally. For correct functioning of the circuit, it is very important t0 select an MKT type of foil capacitor for C2. (M stands for metailised and KT is the standard designation for pciyester foii). (Siemens Application}
Mains power failures cannot be prevented, but methods can be employed to provide a voltage backup for the duration of the fault. For this reason, mains-powered equipment is often fitted with backup batteries (nicad or lithium cells) to maintain operation during a mains power failure. In view of the low currents (microamperes) required for data storage with modern Fl/-lVls, there ls·~ an alternative backup method which is well worth consider- ing: power backup with an electro- lytic capacitor for energy storage! The circuit diagram Tshcvvs .just such an application. The power standby’ capacitor C1 is 4700 ;,iF and with a maximum load current of 10;;/~, the discharge time at an output voltage of 5 V is approxi- mately 53 minutes. The operating voltage of the circuit itself is 15 V, 10 V higher than the output voltage. As long as the 15 V supply voltage ls applied, capacitor C1 charges up to the value of the operating voltage via diode D1. Simultaneously, a bias voltage of approximately 2.3 V is applied to the gate of field effect transistor T1 via voltage divider R1/R2. This ensures that T1 is turned on and capacitor C2 is charged up.
The output voltage at the source t iinal r~· th e second field effect transistor remains a constant 5 V. The two FETs can be thought of as a voltage divider. lf the supply voltage fails, electro- lytic capacitor C1 will become the temporary power supply. Since the gate voltage is removed from T1 it turns off. Capacitor C2 is no longer being charged. However, it‘can only discharge very slowly because T2 has a very high input resistance. The voltage across C2 remains almost constant. Capacitor C1 supplies the operating voltage required for T2 so that it conducts and maintains the output voltage at 5 V. Capacitor Cl discharges very slowly, as a function of its insulation resistance (R|N3 approximately 1 l/ll and the load current flowing. The output voltage at the source lead of T2 remains a constant 5 V, until the voltage across C1 has also dropped to 5 V. lf this voltage drops even further, FET T2 remains turned on but the output voltage decreases proportionally. For correct functioning of the circuit, it is very important t0 select an MKT type of foil capacitor for C2. (M stands for metailised and KT is the standard designation for pciyester foii). (Siemens Application}
Tuesday, September 23, 2014
12V Battery Charger for Sealed Lead Acid
12V Battery Charger for Sealed Lead Acid
There are a number of points we need to cover about the care and use of Sealed Lead Acid batteries.
Firstly, these batteries must be charged, discharged and stored very carefully.
We normally think batteries can be stored for months (if not years) and they will be available for immediate use.
This is not the case with SLA batteries.
If you store a NEW, full charged SLA battery for 6 months or more, you will find it may be fully discharged.
You may also find you cannot charge it!! It may be worthless.
Thats how delicate SLA batteries are.
They must be charged on a regular basis to prevent them discharging to a very low voltage level.
If the terminal voltage of a SLA battery is allowed to go below 8v, aprocess called SULPHATION starts to cover the surface of the plates and prevents the battery being re-charged. The internal resistance of the battery increases and it becomes useless. See products Sealed Lead Acid Battery Charger on Amazon
Parts List of SLA Battery Charger
2 - 1R8 0.5watt resistors
1 - 150R 0.25 watt resistor
1 - 180R
1 - 560R
1 - 1k5
3 - 2k2
1 - 3k3
1 - 4k7
1 - 8k2
1 - 1k mini trim pot
1 - 1n ceramic
2 - 47u 25v electrolytics
1 - 5mm red LED
4 - 1N4148 signal diodes
1 - 10v 0.25watt zener
1 - BC 547 transistor
2 - BC557 transistors
1 - MCR100-6 SCR
1 - 1m red lead
1 - 1m black lead
2 - alligator clips
1 - 2m very fine solder
1 - SLA Battery Charger PCB
Also required:
1 - 12v AC transformer (500mA AC)
1 - power lead
1 - case
Tuesday, September 9, 2014
Test Transmitter for Radio Control Wiring diagram Schematic
This schema is ideal for those with radio transmitting equipment in the control frequency of 35 or 40 MHz, it is a field strength meter, it can check the output power of the transmitters, so you can detect any problems even before the equipment is used. For the test and verification of the correct operation of the transmitter R / C, it must 3 or 4 LEDs lit at a distance of 10 meters.
The length adjustment of the antenna will allow the gauge to operate at a shorter distance.L1 must be initially set to the maximum number of lighting LEDs in a distance of 10 meters or more. Toko coil used in the schema is no longer manufactured but the coil can be constructed at a frequency of 40Mhz.
Test Transmitter for Radio Control Circuit Diagram
Wednesday, September 3, 2014
LED Pulsere circuit for the Christmas Star
This schema can be used to decorate your Christmas star.Here the LED light up gradually and disappear gradually.you can attach 6 LEDs for this.Supply 4.5v - 6v for this schema.Here we have used femous IC LM358 .So you all will be able to find that IC easily.
Parts
IC1__________LM358 Low Power Dual Op-amp
Q1___________BC337 45V 800mA NPN Transistor
R1,R2___________4K7 1/4W Resistors
R3_____________22K 1/4W Resistor
R4______________2M2 1/4W Resistor
R5_____________10K 1/4W Resistor
R6_____________47R 1/4W Resistor
C1______________1µF 63V Polyester Capacitor
D1_____________5mm. Red LED
Sunday, August 31, 2014
LED Flasher for Cars and Motorcycles Wiring diagram Schematic
This is a flasher that uses 4 high brightness LEDs that can be used in Automotive, Motorcycle or bicycle. It uses the IC 555 which is a monostable to adjust the flasher you can use the RV1, which can be a potentiometer or trim pot 100k. If built in SMD it fits within the own flashlight.
LED Flasher for Cars and Motorcycles Circuit Diagram
Thursday, August 28, 2014
Simple Sub carrier Adapter For Fm Tuners Wiring diagram Schematic
Simple Sub carrier Adapter For Fm Tuners Circuit Diagram. In this schema Op amp Ul and its associated components comprise the 67-kHz bandpass filter. A twin-T network, comprised of four 1100-12 resistors and four 0.0022- capacitors, is connected in the feedback network of the op amp.
Sub carrier Adapter For Fm Tuners Circuit Diagram
That gives some gain at 67 kHz and heavy attenuation for frequencies above and below that frequency. An additional passive filter at the input to the twin-T network (containing a 220-pF capacitor and a 10,000- resistor) provides some additional roll-off for frequencies below 67 kHz. In practice, the bandpass-filter action covers a frequency range of about 10 kHz above and below the 67-kHz center frequency. Resistor R18 sets the gain of the bandpass-filter stage. Integrated-schema U2 is a National LM565 phase-locked loop that modulates the 67-kHz fre-quency-modulated (FM) signal from Ul.
The LM565 PLL consists of a voltage- controlled oscillator (VCO) set to 67 kHz, and a comparator that compares the incoming frequency-modulated 67-kHz signal at pin 2 with the VCO signal that is fed into pin 5. The output of the comparator represents the phase difference between the incoming signal and the VCO signal. Therefore, the output is the audio modulated by the subcarrier. A treble deemphasis of 150 is provided by a 0.033- capacitor (at pin 7). The free-miming VCO frequency is determined by the 0.001- capacitor at pin 9 and by the resistance between the positive rail and pin 8 (100 in series with R19). Variable-resistor R19 adjusts the oscillator frequency (also known as the center frequency`) so that the incoming signal is within the lock range of the PLL.
Saturday, August 23, 2014
Simple Automatic Switch For Audio Power Amplifier
Simple Automatic Switch For Audio Power Amplifier Circuit of an automatic switch for audio power amplifier stage is presented here. The schema uses stereo preamplifier output to detect the presence of audio to switch the audio power amplifier on only when audio is present. The schema thus helps curtail power wastage. IC1 is used as an inverting adder. The input signals from left and right channels are combined to form a common signal for IC2, which is used as an open loop comparator. IC3 (NE556) is a dual timer. Its second section, i.e., IC3(b), is configured as monostable multivibrator. Output of IC3(b) is used to switch the power amplifier on or off through a Darlington pair formed by transistors T1 and T2. IC3(a) is used to trigger the monostable multivibrator whenever an input signal is sensed.
Circuit diagram:
Automatic Switch For Audio Power Amplifier Circuit Diagram
Under ‘no signal’ condition, pin 3 of IC2 is negative with respect to its pin 2. Hence the output of IC2 is low and as a result output of IC3(a) is high. Since there is no trigger at pin 8 of IC3(b), the output of IC3(b) will be low and the amplifier will be off. When an input singal is applied to IC1, IC2 converts the inverted sum of the input signals into a rectangular waveform by comparing it with a constant voltage which can be controlled by varying potentiometer VR1. When the output of IC2 is high, output pin 5 of IC3 goes low, thus triggering the monostable multivibrator. As soon as the audio input to IC1 stops, pin 5 of IC3 goes high and pin 1 of IC3 discharges through capacitor C3, thus resetting the monostable multivibrator.
Hence, as long as input signals are applied, the amplifier remains ‘on.’ When the input signals are removed, i.e., when signal level is zero, the amplifier switches off after the mono flip-flop delay period determined by the values of resistor R8 and capacitor C3. If no input signals are sensed within this time, the amplifier turns off—else it remains on. Power supply for the schema can be obtained from the power supply of the amplifier. Hence, the schema can be permanently fitted in the amplifier box itself. The main switch of the amplifier should be always kept on. Resistors R1 and R2 are used to divide single voltage supply into two equal parts.
Capacitors C1 and C2 are used as regulators and also as an AC bypass for input signals. Diode D1 is used so that loading fluctuations in power amplifier do not affect schema regulation. Transisitor T2 acts as a high voltage switch which may be replaced by any other high voltage switching transistor satisfying amplifier current requirements. Value of resistor R10 should be modified for large current requirement. The LED glows when the amplifier is on. The schema is very useful and relieves one from putting the amplifier on and off every time one plays a cassette or radio etc.
Source : EFY
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