Tuesday, August 31, 2010

95 Watt Laptop Power Supply For Car.




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Datasheet semiconductor component: (PDF Format)

1. MBR1645
2. IRL2505
3. BD139
4. BD140
5. UC3843N


A laptop or anthology computer user while they are abroad from the home or appointment knows that eventually or after they will charge to bung into a mains aperture to top up the batteries. The car cigarette lighter atrium in the car is additionally an electrical aperture but it can alone accumulation 12 V. That’s no botheration for the Laptop Ability Accumulation declared here. The laptop ability accumulation declared actuality plugs into a car cigarette lighter atrium and produces a 19V nominal achievement voltage adjustable by + – 0.5V. The ascribe voltage ambit is from 9.2V to 15V and the achievement voltage shows acceptable adjustment alike with ample fluctuations of the ascribe voltage. The achievement can accumulation 5A continuosly with abrupt excursions up to 10A.

The ability semiconductor heatsinks of this laptop ability accumulation are dimensioned fo 5A connected so continued operation up to 10A will access amusement in the adapter and in acute cases will account the ascribe agglutinate to complain.

20VAC 60 Watt Sunrise Lamp Circuit.



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Datasheet semiconductor component.

1. LM324
2. IRF640
3. IRF740

In this circuit, a 120VAC lamp is slowly illuminated over a approximate 20 minute period. The bridge rectifier supplies 120 DC to the MOSFET and 60 watt lamp. A 6.2K, 5 watt resistor and zener diode is used to drop the voltage to 12 volts DC for the circuit power. The bridge rectifier should be rated at 200 volts and 5 amps or more. In operation, a 700 Hz triangle waveform is generated at pin 1 of the LM324 and a slow rising voltage is obtained at pin 8. These two signals are compared at pins 12 and 13 to produce a varying duty cycle rectangular waveform at pin 14, which controls the MOSFET and brightness of the 60 watt lamp. When power is applied, the lamp will start to illuminate within a minute or so, and will slowly brighten to full intensity in about 20 minutes. You can make that longer or shorter with adjustments to the 270K resistor at pin 9. The 2.2 ohm resistor and .015uF cap connected to the lamp serve to supress RFI. The diode at pin 9 and 10K resistor on pin 8 are used to discharge the 3300uF cap when power is removed. Power should be off for a few minutes before re-starting.

Caution: This circuit is connected directly to the AC line and presents a hazard if any part is touched while connected to the line. Use caution and do not touch any parts while the circuit is connected to the AC line. You may want to use a 9 volt battery connected across the 12 volt zener to check the basic operation. The DC voltage at pins 1,2,3,5,6,7 will all be around 4.3 volts if the circuit is working correctly. If the DC voltages are all correct, you can use a variac to slowly apply the full line voltage and check for proper operation.

88-108 MHz FM Broadcast Transmitter Circuit.



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Datasheet semiconductor component.

1. NE555
2. 2N4392

This circuit will transmit a continuous audio tone on the FM broadcast band (88-108 MHz) which could used for remote control or security purposes. Circuit draws about 30 mA from a 6-9 volt battery and can be
received to about 100 yards. A 555 timer is used to produce the tone (about 600 Hz) which frequency modulates a Hartley oscillator. A second JFET transistor buffer stage is used to isolate the oscillator from the antenna so that the antenna position and length has less effect on the frequency. Fine frequency adjustment can be made by adjusting the 200 ohm resistor in series with the battery. Oscillator frequency is set by a 5 turn tapped inductor and 13 pF capacitor. The inductor was wound around a #8 X 32 bolt (about 3/16 diameter) and then removed by unscrewing the bolt. The inductor was then streached to about a 3/8 inch length and tapped near the center. The oscillator frequency should come out somewhere near the center of the band (98 MHz) and can be shifted higher or lower by slightly expanding or compressing the inductor. A small signal diode (1N914 or 1N4148) is used as a varactor diode so that the total capacity in parallel with the inductor varies slightly at the audio rate thus causing the oscillator frequency to change at the audio rate (600 Hz). The ramping waveform at pins 2 and 6 of the timer is applied to the reversed biased diode through a large (1 Meg) resistor so that the capacitance of the diode changes as the ramping voltage changes thus altering the frequency of the tank circuit. Alternately, an audio signal could be applied to the 1 Meg resistor to modulate the oscillator but it may require an additional pullup resistor to reverse bias the diode. The N channel JFET transistors used should be high frequency VHF or UHF types (Radio Shack #276-2062 MPF102) or similar.

40 Watt Fluorescent Lamp Schematic Diagram.




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The circuit works much like the original Strobos. except that a fluorescent tube is used. Thus, the fluorescent tube zündbereit remains constant, the two electrodes of the tube are continuously transformer Ta1 supplied with electricity. This current makes the two resistance wires of the glow tube in, so the mercury evaporates into the tube and the electron emission is simplified. Ta2 Returns on the rectifier “D1-D4 , the voltage of the multivibrator, the ignition frequency of the tube is responsible for. The speed of the AMV is with potentiometer P1 set. The pulse then passes through R3 to T3, is amplified there and controls the bias for the triac, the conducting of these alternates. If so, then the circuit through the tube and the ballast closes and the tube can light up. The pulses of T3 also enter via the capacitor C3 to the gate of the thyristor Th1. Simultaneously with the closing “of the circuit for the tube is Th1 -conductive and creates a short in the ignition coil current flow, which in turn generates a high voltage on the secondary. This voltage of several thousand volts is now operational on port J7 to a wire outside of the tube. The high voltage at the tube provides the necessary starting voltage so that it starts and can certainly light up until the thyristor Th1 locks again.

The points J1 and J2 to connect with the two electrodes on one side of the fluorescent tube. The points J3 and J4 , connect with the electrodes on the other side. Now stretch a thin insulated!! Wire along the tube and glue it eg. Scotch tape firmly. This wire carries the ignition voltage of several thousand volts to the tube so that they ignite properly. This wire, connect one end with J7 on the board, while the other end must necessarily be isolated. This wire leads except the high voltage pulses that is also voltage. The points with J5 and J6 of the board is one, tube fitting, ballast clamped to (choke, there’s the light trading.) Finally there is the voltage at J8 and J9. Now it should somehow already shine or flash, with the potentiometer, the flash rate can be set.