Pulse-Train Triggering Circuit for Power Control

Typical circuit for welding equipment shown on the following circuit diagram. Turn on delay can be controlled accurately with Potentiometer P2. We can discharge C1 at each line zero voltage using DB1 diode bridge and R6-R7 resistors. The voltage charge will be reset at each new half line cycle and the turn-on delay will be maintained the same. Through both potentiometers, the Transil reduces power dissipation. Here’s the circuit diagram: Note: Transil is a transient voltage suppression diode trademarked by STMicroelectron...

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2N3055 Variable Power Supply

This is simple 2N3055 Variable power supply circuit. This circuit has some advantages such as it it can deliver an output voltage between 1,5 V and 15 V with a 500 mA maximum current and low production cost. If the current consumption do not exceed 350 mA, the circuit has stabilization of better than 2%. Here is the circuit: The potentiometer is used to vary the output voltage. When overloading is happened, a buzzer will sound a alarm. This circuit use auto-oscillating buzzer, type 24. P1 slider voltage and the output voltage are compared by T4. The T3-T5 Darlington base current is stopped when the P1 slider voltage is 0,65 V higher...

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Lab Power Supply

his bench power supply circuit is suitable for your electronic experiment lab. This circuit can be built no on a piece of copper-laminate. The Bench Power Supply was designed to use old lantern batteries, “D”, and “C”. This circuit can produce at least 12v -14v from  old batteries and cells. As a heat-sink, this  circuit uses a board. To connect the components, enamelled wire is used. To keep the transistor cool, it can be bolted. Here is the schematic diagram of the  circuit: The zener is used to regulate The output of this power supply. So, there is voltage approx 1.7v across a red LED and 8.2v between the base-emitter...

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Selectable Voltages 6V, 9V, and 12V Linear Voltage Regulator

We can build a multiple voltage power supply 6, 9, and 12V  (AC-DC Adapter) with the circuit shown in the following schematic diagram.  Not only provide multiple voltage output with single voltage supply, this circuit add the benefit of regulating the voltage for better stability. The TIP31 transistor should be installed with proper heat-sink to prevent overheating. A transformer with rectifier diodes and filtering capacitor can be used to supply this circuit. You can use 1 A 15V transformer with 2200uF filtering capacitor for the AC to DC adapter....

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Automotive/Car Power Adapter For 3V, 6V, or 9V DC Operated Devices

In automotive environment, it’s common that only single voltage power outlet is available. Using  the very popular LM317 voltage regulator IC, we can build a general purpose DC adapter to adapt car’s power outlet voltage (12-14 Volts) to supply small DC devices requiring lower voltage level. On the following schematic diagram for the car power adapter,  we can see that the output voltage depends on the value of R1, which is manipulated by connecting R3 or R4 via switch to program the output.  When connected through the switch, R1 will be in parallel with the selected resistor so the total resistance changes to affect the output...

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Phase Delay Network for 3D Audio Enhancement

3D enhancement is needed to create a fully 3-dimensional sound for most stereo multimedia products. Usually, simple phase-delay circuits is used to produce a widening effect on the perceived sound field. However, there is transaural acoustic crosstalk effect. The following figure shows transaural acoustic crosstalk effect and schematic diagram of simple phase-delay circuits : Transaural acoustic crosstalk effect is a condition where some sound from the right-hand stereo speaker reaching the left ear, and vice-versa. This is an active circuit that uses first-order section to present a phase-shift filter with ft of 1kHz for the quadrature...

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Video-Based Motion Sensor

The design is primarily based on an analog integrator circuit. The circuit integrates (i.e., sums) the input-voltage signal over a defined period of time. Based on an op-amp, the ideal circuit is shown in Figure 3. The factor –(1/RC) is constant, so the resulting output is inverted and proportional to the sum of the integrated values (i.e., proportional to the average of the signal in the integrated period of time). This is all it takes to “compress” the analog video signal. Although it seems complicated at first sight, it should be fairly simple by now (see Figure 4). The integrator is implemented by a National Semiconductor LM6134B, a...

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LCD thermometer for engine of vehicle with IC-L7136 circuit

Many car product in thermo sensor ,so i would like to show you the LCD thermo sensor which can modify for your car. LCD car thermo circuit When the thermometer is the IC thermo sensor (S8100) or diode (1S1588) is used as thermal sensors. When using the IC thermo sensor, the thermometry to +100 ° C -40 ° C are possible. Also, when using the diode, measured at 150 ° C from -20 ° C are possible. Both sensors are contained in the set. This time I used the diode as a heat sensor to measure more than 100 ° C. ICL 7136 of Intersil (Harris) used for the thermometer and measure the voltage change minute by management before the temperature...

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Automatic Intruder Burglar Alarm

This is a burglar alarm circuit written by Ron J. Its features include automatic Exit and Entry delays and a timed Bell/Siren Cut-Off. It’s designed to be used with the usual types of normally-closed input devices such as – magnetic reed contacts – micro switches – foil tape – and PIRs. But it can be Easily Modified to accept normally-open triggering devices – such as pressure mats. Hot It works This intruder burglar alarm is easy to use. First check that the building is secure and that the green LED is lit. Then move SW1 to the “set” position. The red LED will light. You now have about 30 seconds to leave the building. When you...

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Program for Deadlock detection algorithm

INPUT: enter total no. of processes : 4 enter claim matrix : 0 1 0 0 1 0 0 1 0 1 0 0 0 0 1 1 0 1 0 1 enter allocation matrix : 1 0 1 1 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 enter resource vector : 2 1 1 2 1 enter the availability vector : 0 0 0 0 1 OUTPUT : deadlock causing processes are : 1 2 #include<stdio.h> #include<conio.h> void main() { int found,flag,l,p[4][5],tp,c[4][5],i,j,k=1,m[5],r[5],a[5],temp[5],sum=0; clrscr(); printf("enter total no of processes"); scanf("%d",&tp); printf("enter clain matrix"); for(i=1;i<=4;i++) for(j=1;j<=5;j++) { scanf("%d",&c[i][j]); } printf("enter allocation matrix"); for(i=1;i<=4;i++) for(j=1;j<=5;j++) { scanf("%d",&p[i][j]); } printf("enter resource vector:\n"); for(i=1;i<=5;i++) { scanf("%d",&r[i]); } printf("enter...

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Types of Stepper Motors

Stepper motors come in two varieties: permanent magnet and variable reluctance. (The reader may be familiar with hybrid motors, which are indistinguishable from permanent magnet motors from the controller’s point of view.) Permanent magnet motors usually have two independent windings, with or without center taps. Center-tapped windings are used in uni polar permanent magnet motors. This can you see in the figure (1). Bipolar permanent magnet and hybrid motors are constructed with a mechanism similar to that used in uni polar motor, except that the two windings are wired without center taps in the Figure 2. The motor itself is simpler, but...

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