Sine Wave To TTL Converter

As the title implies, the present circuit is intended to convert sinusoidal input signals to TTL output signals. It can handle inputs of more than 100 mV and is suitable for use at frequencies up to about 80 MHz. Transistor T1, configured in a common-emitter circuit, is biased by voltage divider R3–R5 such that the potential across output resistor R1 is about half the supply voltage. When the circuit...

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NTSC PAL TV Signal Identifier

This circuit is able to identify PAL and NTSC video signals. Its output is high for an NTSC signal and low if the signal is PAL. This output signal can be used, for example, to automatically switch in a colour subcarrier converter or some other device while an NTSC signal is being received. One application is for the reception from satellites of free-to-air TV signals, which in Australia generally...

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Video Amplifier Circuit Diagram

The video amplifier in the diagram is a well-known design. Simple, yet very useful, were it not for the ease with which the transistors can be damaged if the potentiometers (black level and signal amplitude) are in their extreme position. Fortunately, this can be obviated by the addition of two resistors. If in the diagram R3 and R4 were direct connections, as in the original design, and P1 were fully...

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White LED Lamp

Nowadays you can buy white LEDs, which emit quite a bit of light. They are so bright that you shouldn’t look directly at them. They are still expensive, but that is bound to change. You can make a very good solid-state pocket torch using a few of these white LEDs. The simplest approach is naturally to use a separate series resistor for each LED, which has an operating voltage of around 3.5 V at 20...

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Dual Input Combining Stereo Line Amplifier

This circuit takes two separate line-level stereo (L & R) signals and combines them into one stereo (L & R) output, thus avoiding the need to switch between two pairs of input signals. In the author’s application, it is used to feed the stereo audio from a TV receiver and a DVD player into an external amplifier. The need for the circuit arose because of a design peculiarity in the TV receiver....

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HQ Notch Filter Without Close Tolerance Components

A notch for a narrow frequency band of a few per cent or even less normally requires close-tolerance components. At least, that’s what we thought until we came across a special opamp IC from Maxim. In filters with steep slopes, the component tolerances will interact in the complex frequency response. This effect rules out the use of standard tolerance components if any useful result is to be achieved....

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Discrete Robot

This simple robot, which responds to light and avoids obstacles, can be built without using a microcontroller, programmer or PC. The only ‘special’ component in the circuit is a window discriminator (a fancy version of a window comparator). Resistors R1 and R2 in combination with light-dependent resistors LDR1 and LDR2 form a voltage divider (with the current being limited by R1 and R2 for bright...

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RESISTOR TO REDUCE L200 POWER DISSIPATION ELECTRONIC DIAGRAM

RESISTOR TO REDUCE L200 POWER DISSIPATION ELECTRONIC DIAGRAMInstead of in series with the input, the resistor R can be connected between pins 1 and 2 of the IC if the load is constant. You can see this in the right figure. This will make some part of the load current flows through the resistor and the other part through the devi...

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Speaker Headphone Switch For PCs

If you need to use a headset with your PC, then you will know how frustrating it is continuously swapping over speaker and microphone cables. This is even worse if the PC is parked in a dark corner and the hard-to-read writing on the sound card sockets is covered in dust. This simple switch box eliminates all these problems. It sits on top of the desk and connects to the PC with stereo one-to-one...

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Up Down Fading LED Circuit

This circuit drives a motor clockwise / anticlockwise via a pot and reduces the speed to zero when the pot is in mid-position. The current is limited to 200mA and the voltage across the motor is less than 6v, but the circuit shows the principle of Pulse Width Modulation (providing powerful bursts of current to the motor to create a high or low RPM under load) and both forward/reverse RPM via the H-bridge...

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Alarm Clock With Day Selector

This  circuit disables an alarm clock on Saturdays and Sundays when people like to sleep in but enables normal operation on Mondays to Fridays so that people rise in time for work or school. The core of the circuit is a 4017 decade counter which acts as the day counter and it is used in conjunction with a desk clock which acts the alarm and a watch module with alarm function which provides one...

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1963 Dodge Dart Electrical Wiring Diagram

1963 Dodge Dart Electrical Wiring DiagramThe Part of 1963 Dodge Dart Electrical Wiring Diagram: direction signal switch connector, cigar lighter, ammeter, heater blower switch, the stop light and direction signal, tail light, beam selector switch, light switch, luggage compartment, circuit breaker, gas gauge, backup light, printed circuit connector, parking brake warning light and switch, etc. Features:...

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1999 Lincoln Continental Wiring Diagram

1999 Lincoln Continental Wiring DiagramThe Part of 1999 Lincoln Continental Wiring Diagram: fuse junction panel, autolamps, multifunctionswitch, hazard, lighting crtl module, shift lock actuator, hazard flasher, switch input, stoplamp, passenger, delaved exit, turn left/ri...

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Lit Motors Unveils Self Balancing Electric Vehicle C 1

Introducing the C-1, the world’s first gyroscopically-stabilized “rolling smart phone”. This vehicle combines the efficiency and freedom of a motorcycle with the safety and convenience of a car. Offering the “alternative to alternatives” on an exciting and safe platform, the C-1 transforms your daily commute into something to look forward to. Influenced by Scandinavian design, the exterior of...

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Sensitized Solar Cells Based on Zinc Compounds

Researchers at the University of Basel in Switzerland say they have developed a new approach to producing environmentally sustainable photovoltaic devices. The research team developed a new method for producing dye substances and attaching them to the surface of titanium dioxide nanoparticles. With this they demonstrated that simple dye compounds based on zinc, a readily available metal, can...

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12V DC to 220V 100W Inverter Circuit Diagram

12V DC to 220V 100W Inverter Circuit Diagram This is 100W inverter circuit. It uses 4047 IC and IRF540 Mosfet instead of 2N3055 transistor. Power output is 100W from 2-3A transformer. ...

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Build a Doorbell Circuit For Deaf People

This circuit provides a delayed visual indication when a door bell switch is pressed. In addition, a DPDT switch can be moved from within the house which will light a lamp in the door bell switch. The lamp can illuminate the words "Please Wait" for anyone with walking difficulties. Doorbell Circuit DiagramNotes:The circuit uses standard 2 wire doorbell cable or loudspeaker wire. In parallel with...

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Single Transistor Relay Toggle

The circuit below requires a double pole, double throw relay in conjunction with a single transistor to allow toggling the relay with a momentary push button. One set of relay contacts is used to control the load, while the other is used to provide feedback to keep the relay activated or deactivated. Several push buttons can be wired in parallel to allow toggling the relay from different locations.In...

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Switching Power Supply Using the LMZ14202H

Using the LMZ14202H power switching controller, can be designed a very simple switching power supply circuit that can provide a fixed output voltage covering a wide range of voltages .Switching Power Supply Circuit diagramThis power switching power supply electronic project will provide a fixed output voltage between 5 and 30 volt from an input voltage between 8 and 42 volt at a maximum output current...

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SW Receiver Using MK414

A Short Wave Receiver based on the MK484 (formerly ZN414) that includes the tropical bands and 49 metre bands.SW Receiver Using MK414 Circuit DiagramNotes:The original data sheet for the MK414 states a maximum working frequency is around 4 MHz. SW transmissions are so powerful that this receiver will work well with signals up to about 6 or 7 MHz. The 10k resistor controls the operating voltage for...

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Economy Radar Detector Circuit

Circuit DiagramDescriptionThis circuit uses a 1458 dual op-amp to form a radar detector. C1 is the detector of the radar signal. The first op-amp forms a current-to-voltage converter and the second op-amp buffers the output to drive the piezo transducer. R5 sets the switching threshold of the second op-amp; normally it is adjusted so that the circuit barely triggers on background noise, then...

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Voltage Rating Tester for Zener Diode

I have teamed up with Magazine Mikro Elektronica for this project. Please visit their site. I am very grateful to Aleksandar Dakic for the kind translation into Serbian and Romanian languages.Voltage Rating Tester for Zener Diode Circuit DiagramNotes:Using a single 555 Timer IC and a small transformer to generate a high voltage, this circuit will test zener diodes of voltage ratings up to 50VDC. The...

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