TREE

A photo diode is a PN junction or PIN structure that when light reaches the junction, it excites an electron thereby creating a free electron positively charged. This mechanism is also known as the photoelectric effect, common in transistors, diodes and ICs are made ​​of semiconductors, and contain PN junctions. Almost all of the potentially active constituents are a photo diode and may be used as a photo sensor. The PN junction needs to be exposed to light, so to use a semiconductor diode as a light bulb must have a transparent glass, these diodes with  these characteristics can be used to measure the light intensity.  Circuit diagram of a light intensity meter with diode.   a test circuit diode light sensor List of components: D1 1n148 or any other photo-sensitive element T1, T2 BC548 or similar C1 680n R1 2M Above this circuit that is very popular, it works with LEDs, photodiodes and photo-resistors. V is a voltmeter which can be a multimeter.

It is sometimes disturbing to have a AM radio in a countryside and not being able to get the reception clearly. It is simply because of the distance of the radio station and also the strength of the station. The only solution is to attach a powerful antenna to the receiving radio the uniqueness of the antenna lies in its simplicity and cost. The basic knowledge of making an antenna is there in the back end. Generally, the frequency range of amplitude modulation in 560 to 1650 KHz in order to resonate the LC circuit that that is the antenna (2πfL=1/(2πf_c )) 4πf^2 LC=1.Using this formula and using a 30- 450 pF gang condenser the handy inductance built on a 350ft long PVC pipe works quite well. The inductance built around a PVC pipe is basically an air core inductor, the inductance of which is govern by the formula L=(R^2 N^2)/(9R+10l) where L is inductance in μH, R is coil radius in inches, l is coil length in inches and N is number of turns. The calculated inductance in tune with 3...

Download the Eagle3D software and Install it. Open your board file in Eagle. Click on ‘ULP’ icon: A new window will open asking for a ‘.ulp’ file. Browse into your Eagle3D directory (where you installed it) and select the file '3d41.ulp'. Now select the language you want, and then browse for the output file. Make sure your PCB layout contain ‘dimension’ else you will get en error message: You can do this by clicking on ‘wire’ icon; select the dimension from drop down list (20) and draw a border across your layout. If every thing goes right then a new window will pop up: You can change camera angle, lights, colors etc. For now, just click on ‘create POV-File and Exit’ button. After some seconds it will ask various questions about your board components answer as best as you can. Now you will have a ‘.pov’ file. Download and Install the 32-bit version POV-Ray software . Click on the ‘Open’ file icon, and locate your .pov file created in the previous step. We need to p...

Description: This circuit takes an ordinary loudspeaker and allows it to be used in reverse, as a microphone. Circuit diagram Notes: This circuits allows you to use a cheap loudspeaker as a microphone.Sound waves reaching the speaker cone cause fluctuations in the voice coil. The voice coil moving in the speakers magnetic field will produce a small electrical signal . The circuit is designed to be used with an operating voltage between 6 and 12 volts dc. The first transistor operates in common base mode. This has the advantage of matching the low input impedance of the speaker to the common base stage, and secondly has a high voltage gain. The second stage is direct coupled and operates in emitter follower. Voltage gain is slightly less than unity, but output impedance is low, and will drive long cables. Speech quality is not as good compared to an ordinary or ECM microphone, but quite acceptable results can be obtained. Speaker cones with diameters of 1 inch to 3 inches may be used....

Now we’ll prepare the glass fiber. We are going to cut it a bit bigger than our design, leaving a small margin. We cut the page design, where the “Top” parts were in normal vision. We attach the page to the glass fiber with a little bit of sellotape. We choose two pads which are situated at both extremes of the design, one that is at the upper part and the other one at the other extreme end, but in the lower part. We make a hole with a hand drill in the mentioned pads. The hole should be 0.8 mm wide. We have to look carefully at the pads we have chosen, since now we have to make a small hole with a pin in the photograph paper, on the page which coincides with “Top” mirrored part and with the “Bottom” part. We now leave a photograph paper with design and we take a kitchen towel and a solvent. We remove the page which was attached to the glass fiber and we rub the copper with the kitchen towel dipped into the solvent, so that it becomes shiny on both sides. Once we have don...

Generally for connecting an LCD display to an Arduino using 7 strands, it usually breaks the leg that has any projects that remain few ports to be used. But there is a way, using an IC 74LS164 (8-bit serial shift register), a resistor and a diode, but it's not just hardware, you have to use a library. This Arduino library for connection of 2-wire or 3-wire using HD44780 compatible LCD display via shiftregisters. This circuit is considered "deprecated", but it's worth testing. LCD Display on the Arduino Circuit 

Description The Basic Alarm Circuit has an automatic Exit/Entry Zone - an Instant Alarm Zone that will accept both normally-closed and normally-open triggering devices - and an "Always On" 24-hour Personal Attack/Tamper Zone. By using the Expansion Modules - you can add as many extra alarm zones as you require. Schematic Diagram The Alarm is armed and disarmed by SW1. Before you move the switch to the "set" position - all the green LEDs should be lighting. You then have up to about a minute to leave the building. As you do so - the Buzzer will sound. It should stop sounding when you close the door behind you. This indicates that the Exit/Entry loop has been successfully restored within the time allowed.  When you re-enter the building - you have up to about a minute to move SW1 to the "off" position. If SW1 is not switched off in time - the relay will energize - and the main bell will ring. It will continue ringing for up to about 40 minutes. But it can...

 At this point is a Solar Charger Circuit to is used to charge information Acid otherwise Ni-album batteries using the solar energy power. The circuit harvests solar energy to charge a 6 volt 4.5 Ah rechargeable battery in favor of various applications. The stallion has Voltage and Current supervision and terminated voltage restrict sour facilities. Circuit uses a 12 volt solar panel and a changeable voltage supervisor IC LM 317 . The solar panel consists of solar cells each one rated on 1.2 volts. 12 volt DC is presented from the panel to charge the battery. Charging current passes through D1 to the voltage watchdog IC LM 317. By adjusting its Adjust pin, output voltage and current can subsist regulated. VR is placed amid the adjust pin and ground to provide an output voltage of 9 volts to the battery. Resistor R3 confine the charging current and diode D2 prevents discharge of current from the battery. Transistor T1 and Zener diode ZD conduct yourself having the status of a stop ...

Two Light Emitting Diodes slowly light up and fade away due to the circuitry, giving it a feel of blinking red eyes in darkness. It is the perfect way to set up your own horror show in Halloween. It can also be installed in series for the Christmas tree or during Diwali or a decorative power indicator for the daily appliance. A 3 volt linear wave is generated at Pin 1 via LM 1458 IC and followed by a transistor which buffers the emission. A 47 K resistance coupled with a 22uF capacitor is joined at Pin2 to limit the frequency to 0.5Hz. The rate can be varied using a 100K pot(potentiometer) replacing the 47K resistor. Two operational amplifiers govern the circuit. The transitional voltage is produced by the first op-amp which slowly modulates voltage between 3 to 6 volts. The second op-amp supplies alternating voltage of 2 and 7 volts to charge the capacitor and discharge it via constant current. Two 47K resistors establish a fixed voltage when joined across Pin 3 & 6 to keep...

Small 1.5V to 5V or 12V DC/DC converter with LT1073 chip. The IC is available in three different versions, depending on output voltage. Two with fixed output voltage of 5V and 12V, and the most interesting that can be adjusted. The adjustment is done through a voltage divider with two resistors, of mass, output and Terminal 8, internally connected to the voltage comparator IC, which is responsible for stabilizing the output voltage. LT1073 has an internal everything you need to make a small DC / DC converter with a low operating voltage of only 95μA 1V and consumption without load. If you do not have a meter inductance, the inductive part of the drive is a bit more complicated to make, but we shall see some possible solutions. Capacitor also recommended by the manufacturer for the circuit is a bit hard to get, I have used a tantalum recovered from another power source, and the ripple voltage at the output is quite low. Last but not least, say that the diode has to be a fast, not...