Wiring circuit

Wednesday, October 22, 2014

2 Transistor Line Follower Robot

Make a line follower robot can be done with two transistors. Line Follower Robot series is one of the two transistors contor robot line follower circuit is in Bagun with two NPN transistor and the motor driver as well as processing of sensor signals.

In the circuit of line follower robot consists of two parts of the same, only different functions for the motor driver the right and left. Sensor circuit of line follower robot uses the LDR and LED. LDR sensor sensitivity can be set with the VR 10 is mounted in series with the LDR. For more details, see the following figure.

Line Follower Robot series 2 Transistor

The working principle of the motor driver circuit between the right and left together, when the LDR get the reflection of light from the LED LDR resistance will decrease and make the transistor saturation and motor gets supply and rotates so that the robot moves forward. So at the moment is not the case then the motor did not get a supply, for example, only one sensor is exposed line and make the LDR did not receive the reflected light is then Motr in the stationary and the other motor rotates and makes the LDR are back in the reflection of light and the robot moves forward again.

Friday, October 17, 2014

Video Line Driver

This circuit is a video line driver specifically intended for use with a single-ended power supply. As a matter of fact, the synchronised outputs of a line driver for composite-video signals go negative with respect to ground. In order to be able to process these negative signals in a circuit powered from a single-ended supply, it is necessary to AC-couple the input of the opamp as well as level-shift the signal in the positive direction.

Circuit diagram :

Video Line Driver Circuit Diagram

The input is terminated into a 75 Ω resistor (R1). From here, the signal passes through AC-coupling capacitor C2 and is applied to potential divider R2-R3, which provides the necessary DC-offset. The shift into the positive direction amounts to +1.7 V, with the values shown in the schematic. To avoid any misunderstandings we should add that this value is fairly critical. Deviating from the values shown can lead to distortion in the complementary input stage of the opamp that has been used here, and this of course, has to be avoided.

PCB-Layout :

Video Line Driver PCB-Layout

Because we provided the circuit with its own voltage regulator circuit (IC2), just about any mains adapter will suffice for the power supply. The current consumption is less than 20 mA. The construction of the line driver using the accompanying printed circuit board layout is no more than a simple, routine job.

Parts List :

Resistors:
R1,R7 = 75Ω
R2...R4 = 4kΩ7
R5,R6 = 1kΩ

Capacitors:
C1,C4,C5,C7C10,C12 =
100nF
C2 = 47µF 16V radial
C3,C11 = 10µF 6 V radial
C6 = 220µF 6 V radial
C8 = 1000 µF 6V radial
C9 = 100µF 16V radial

Semiconductors:
D1 = 1N4001
IC1 = OPA353UA
IC2 = 78L05

Miscellaneous:
PC1-PC6 = PCB solder pin
Case, e.g., Hammond type
1590A

Tuesday, September 16, 2014

AC Line Current Detector Wiring diagram Schematic

This schema diagram will detect AC line currents of about 250 mA or more without making any electrical connections to the line. Current is detected by passing one of the AC lines through an inductive pickup (L1) made with a 1 inch diameter U-bolt wound with 800 turns of #30 - #35 magnet wire. The pickup could be made from other iron type rings or transformer cores that allows enough space to pass one of the AC lines through the center.

Only one of the current carrying lines, either the line or the neutral should be put through the center of the pickup to avoid the fields cancelling. I tested the schema using a 2 wire extension cord which I had separated the twin wires a small distance with an exacto knife to allow the U-bolt to encircle only one wire.

AC Line Current Detector Circuit Diagram

The magnetic pickup (U-bolt) produces about 4 millivolts peak for a AC line current of 250 mA, or AC load of around 30 watts. The signal from the pickup is raised about 200 times at the output of the op-amp pin 1 which is then peak detected by the capacitor and diode connected to pin 1. The second op-amp is used as a comparator which detects a voltage rise greater than the diode drop. The minimum signal needed to cause the comparator stage output to switch positive is around 800 mV peak which corresponds to about a 30 watt load on the AC line.

The output 1458 op-amp will only swing within a couple volts of ground so a voltage divider (1K/470) is used to reduce the no-signal voltage to about 0.7 volts. An additional diode is added in series with the transistor base to ensure it turns off when the op-amp voltage is 2 volts. You may get a little bit of relay chatter if the AC load is close to the switching point so a larger load of 50 watts or more is recommended. The sensitivity could be increased by adding more turns to the pickup.

Tuesday, September 9, 2014

Live line Detector

If the unit is brought close to a live conductor (insulated, and even buried in plaster) capacitive coupling between the live conductor and the probe clocks the counter, and causes the LED to flash 5 times per second, because the 4017 IC divides the mains 50Hz frequency by 10.When remote from a live line, the unit stops counting, the LED resulting permanently off.

Live-line

Parts:
C1____________100nF 63V Polyester or Ceramic Capacitor D1_____________Red LED (any type) IC1____________4017 Decade counter with 10 decoded outputs IC P1_____________SPST Pushbutton B1_____________3V Battery (two 1.5V AA or AAA cells in series etc.) Sensing probe__3 to 15 cm. long, stiff insulated piece of wire Notes: * Sensitivity can be varied using a more or less long sensing probe. * Due to 3V operation, the LEDs current limiting resistor can be omitted.

Wednesday, September 3, 2014

Free power from the telephone line

I think this schema will be very useful for you all to get some electricity when you are in a power cut.You can get power to light up several LED bulbs. I suppose Even a LED is very valuable when you are in the dark.after building this schema connect your schema to the telephone line through red and green wires. to get power connect your cables to + and _ lines.

This is only for educational purpose.Free schema diagrams 4U team doesnt get any responsibility of misusing this schema.

# Build this schema on a PCB

Monday, September 1, 2014

Audio Line Driver

Audio line driver schematics:

This preamplifier has a low output impedance, and is designed to drive long cables, allowing you to listen to a remote music source without having to buy expensive screened cables. The very low output impedance of around 16 ohms at 1KHz, makes it possible to use ordinary bell wire, loudspeaker or alarm cable for connection. The preamplifier must be placed near the remote music source, for example a CD player. The cable is then run to a remote location where you want to listen. The output of this preamp has a gain of slightly less than one, so an external amplifier must be used to drive loudspeakers.