Here is a project Device switching using password by innovative group Dreamlover technology, lets the user to lock their device with password. The block diagram of device switching using password is shown in figure 1. As the circuit device switching using....

Here is a simple IR headphone circuit that is suitable for listening to TV or radio with out disturbing others. For beginners the IR headset is a better option than FM head sets because they often produce desirable sound quality with out tuning as well as....

This is a fun and useful circuit for demonstrating high frequency high voltge. It can produce up to about 30KV, depending on the transformer used. It is cheap and easy to make, thanks to the standard TV flyback transformer used. It can power LASERS (although....

Wrap hundreds of turns of magnet wire around the paper tube. Connect this home-made inductor in series with an AC power supply and lamp to form a circuit. When the tube is empty, the lamp should glow brightly. When the steel bar is inserted in the tube, the....

Has high input impedance und low output impedance, to reduce droop in output voltage between pulses. Staircase is generated by pump D2-C2, which is boostrapped on output to maintain equal amplitude on each step. Circuit values shown give 10 steps with 12-V....

This circuit uses a digital pot to allow the microcontoller to automatically adjust the gain of the circuit to suit the ambient audio volume, but you could replace this with a standard pot if this isn`t needed. The low pass filter is a copy of Graham....

A solar cell radio used a 3V (or two 1.2V) Ni-Cad battery in it. The battery can not be removed. It use a mini jack socket for charging. Its quiet difficult...

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Typically the input protection fuse of your DMM will blow in the middle of a demonstration or an exciting phase of your construction work. Spare fuses are always hard to find, and if available take a lot of time to install. This circuit replaces the fuse by....

When low/high input is voltage in binary form, as obtained from converter circuit (also given in artide) fed by digital voltmeter, circuit produces Iow pitch for binary 0 and high pitch for binary 1 when S2 is set at D for digital voltmeter mode. Recognition....

The circuit shown flashes the LED briefly (to get your attention) and stays on as long as the power is on ( Fig. 1 ). The venerable 555 timer IC can be put to use in this type of application. The circuit is a standard astable multivibrator with resistors RA,....

This is the 40Mhz RF amplifier circuit. The sensitivity of a receiver may be significantly increased if this circuit is inserted between the receiver and the antenna. The amplifier circuit does not use resonant circuits and is suitable for both medium and....

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This simple counter can be used to count pulses, as the basis for a customer counter (like you see at the doors of some stores), or for anything else that may be counted. The circuit accepts any TTL compatible logic signal, and can be expanded easily (see....

When the switch is opened, the timer produces an approximate 1 second clock signal, decrementing the counter until the 0 count is reached. When the zero count is reached, the `carry out` signal at pin 7 of the counter moves low, energizing the 12 volt relay....

Design cicuit using a power mosfet to replace the NTC (thermister) that many Mag623 users employ to prevent their bulbs from flashing. Although inexpensive and easy to hook up, NTC`s run quite hot. They are also affected by ambient temperature, require a....

The most important schematic to know, one that is almost always required for every robot whether you`re a beginner or advanced, is a circuit to control your robots` power source. You cannot just hook up a battery directly to everything and expect it to work.....

The circuit consists of four stages of active bandpass ftltering provided by two type A747 integrated-circuit dual op amps and includes a simple threshold detector (diodes D1 and D2) between stages 2 and 3 to reduce low-level background noise. Each of the....

Beeps if you leave open the door over 20 seconds This circuit, enclosed into a small box, is placed in the fridge near the lamp (if any) or the opening. W....

The frequency is constant varying between two set values, on the oscilloscope screen you get a frequency spectrum with the response curve of the two circuits. The input voltage of the receiver is 0. 1 Volt peak-peak, the voltage across the detector circuit....

The basic charging circuit produces in excess of 500V+, depending on the inductor used, leakage of various components, etcetera. The current output is limited by a 10Mohm resistor, which keeps short-circuit current under ~60uA. Thus this is a relatively safe....

Here`s a very simple, but practical circuit, which is used to check the type of LAN cables (straight or cross) as well as possible faults. So we use a unit that has 8 outputs, each one of which produces a pulse successivly. Only one output can be high at any....

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Going camping nowadays involves taking lots of electronic equipment whether for day to day running or for fun and entertainment. Most of the time a charged lead acid battery and a power inverter would be used to ensure a smoothly organized holiday where....

A Solid State Relay is in reality not a relay after all. There`s no `relay` found, just the electronics circuit which does the switching. It operates a similar way as a relay; it is possible to use a low voltage to switch a higher voltage or better than....

This schematic is taken directly from the Altera ByteBlaster datasheet or manual. They spill out all the fine print and details of how the connector works & what connections go where. Find the datasheet on their website or through google and give it a good....

This circuit is used J-FET for recieve signal to buffer from LED, About Output voltage, We used IC 1458 or LM1458, while in the dark is about 7 volts and the drop about 2 volts in full sun. The LED voltage buffered by a junction FET transistor and then....

Controlling household electrical gadgets or any electrical equipment remotely can be fun. Controlling gadgets like a TV set or a DVD player through a remote may look pretty common to us and we are very used to with the experience, however for controlling....

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An internally compensated operational amplifier is described which has been fabricated using n-channel Al-gate MOS technology. Only enhancement mode devices are used, and the circuit has been designed so that its performance is insensitive to process....