wiring and diagram

The AC mains line that we get in our household electric socket outlets, may at times be full of dangerous fluctuations. These may either be in the form of a sudden high voltage or a low voltage. Both the situations can be very “fatal” to our sophisticated electronic equipments like TVs, DVD players, refrigerators, computers etc to name a few.

A simple electronic part such as an LED can play an important role in displaying the condition of this AC mains voltage and warn us of a possible electrical hazard.

Yeah, we will exactly learn how to make ac voltage indicator from led through a construction of a little electronic circuit.

You will need the following mentioned parts for the project:

TRANSISTORS T1, 2, 3, 4, 5 = BC547

ZENER DIODE Z1----Z5 = 3 VOLTS / 400mW

RESISTORS R 1—R10 = 1 K ¼ WATT, CFR.

CAPACITOR C1 = 1000uF/25v,

DIODE D1 = 1N4007

LED 1, 2, 3, 4, 5 = RED 5mm DIFFUSED

PRESET P1, 2, 3, 4, 5 = 47K LINEAR

GENERAL PURPOSE BOARD = 6” BY 2”

TRANSFORMER = O – 6 VOLTS/ 500mA

  It is completed through the following few easy steps:

 In the procured general purpose board, with the help of the circuit schematic start inserting the transistors first in a straight line and solder their leads.

Similarly insert and solder the resistors, zener diodes, LEDs, capacitors, presets etc. in an organized manner and solder them with reference to the circuit diagram.

The following testing details will furthermore help you to understand exactly how to make ac voltage indicator from led:

For testing the completed circuit board you will require a transformer with multiple voltage outputs.

Connect the transformer to the AC mains; also connect the common secondary output of the transformer to the negative point of the circuit.

Make an alligator clip/ wire assembly. Solder the wire end of the clip to 1N4007 diode input.

Now bite the clip to the 3 volt output of the transformer, adjust P1 so that the first LED just starts glowing.

As above go on connecting the clip to 6, 7.5, 9 and 12 volts of the transformer and adjust the presets P2, P3, P4 andP5 so that the relevant LEDs just start to glow at the respective voltages.

This completes the testing and the setting of the circuit.

Finally join the 6 volt transformer to the circuit and switch ON the power. You will find that LED 1, 2 and 3 are glowing brightly, LED no.4 is glowing with less brightness while the last LED is completely OFF, indicating a safe level of AC mains voltage.

Now in case the voltage exceeds a high level (above 260 volts) the last LED will start glowing brightly indicating a dangerous situation.

If the voltage drops to a dangerous level (below 160 V) LED 3 and may be LED 2 may cease to glow, again indicating a bad low voltage.

When it comes to personal usage, solar panels can become a difficult parameter to digest. While selecting solar panels, folks tend to depend entirely on the manufacturer and the technical personnel, and therefore are unable to take personal decisions with the devices technical specs and quality.

In this article we’ll discuss some of the basic technical points related to solar panels which will help us to understand solar panels from the core and use them efficiently. The discussed points are though very basic, provides general yet useful inputs regarding these outstanding devices.

As discussed in the above paragraph, solar panels convert direct sunlight incident over their surface into electricity. Since the generated electricity is directly proportional to the striking sunrays, the direction and the intensity of the rays become the main factors affecting the outcomes.

Therefore, the voltage magnitude available across solar panel output terminals may vary according to the intensity and the amount of sun light available over its surface, and varies linearly.

Typically every solar panel is associated with a particular set of technical and electrical specifications, which defines its functioning and application.

The following technical specs can be normally witnessed:

Optimal voltage,

Optimal current,

Maximum voltage,

Short circuit current,

Maximum wattage,

Fuse rating.

As a customer, the parameters which would be particularly important are: optimal voltage, optimal current, short circuit current and the fuse rating.  

Though the installations will be handled by the associated engineer, the user should also be aware regarding the operating terms related to these devices. This would greatly help them to analyze, customize and even troubleshoot some of the common faults accompanied with these devices.

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Optimal voltage should always be greater than the minimum required voltage for the application. In fact it should greater than twice the required value. This makes sure that even under gloomy conditions the output from the panel might be just enough for the needs or above the minimum requirements.

 During optimal conditions, the excess voltage from the panel is appropriately tailored by the associated voltage regulator such that only the required magnitude reaches the application; normally this voltage will be used for charging an inverter battery.

Maximum voltage can be ignored as it refers to the ability of the panel to produce electricity under maximum artificial forced light conditions, not something related to normal usage.

Short circuit current is the magnitude of current which causes the output of the solar panel reach a zero level when its output leads are joined or shorted, a point at which the panel output indicates a zero voltage and fails to operate.

 The condition may cause severe deterioration or even a permanent damage to the device. This specification indicates the loading current of the panel which cannot be exceeded above the rated value; typically this value must be kept at around 50% of the specified value.

The maximum fuse rating is the amperage of the fuse wire connected in series with the panels output. This rating should be a shade lower to the above short circuit current rating so that the fuse instantly blows-of before the current can exceed and reach the dangerous short circuit conditions.

The maximum wattage spec may also be ignored because once the optimal current and voltage are selected appropriately, the wattage which the product of the above two parameters, automatically adjust with the requirements.

 However today’s modern solar voltage regulators and charger associated with solar panels take care of the most critical situations, eliminating short circuit, overload or over voltage situations, safeguarding both the solar panel and the inverter/battery stage which are integrated to the panel for the desired operations.

Although the solar panel may be generating just about enough current for your batteries, it may be quite useless once the sun rays stop reaching the surface of the panel. 

To fight against this issue, solar trackersmechanisms are normally employed with solar panels so that the panels keep generating electrical power at the most efficient rates throughout the day irrespective of the sun’s position in the sky.

 This also facilitates the incorporation of relatively smaller sized solar panels because now the optimal voltage can be selected just close to the actual requirement and does not need to be twice or thrice than the actual need.

The explained circuit can be easily made at home by any school kid and used for displaying in his science fair exhibition. The circuit is a simple cell phone charger that may be operated in conjunction with any DC source, from a car or a motorcycle battery or from any ordinary 12 V AC DC adapter.

Nowadays we find most of the vehicles have their in built cell phone battery charger units which surely becomes very handy for travelers who mostly remain outdoors travelling in their vehicle. 

The proposed cell phone charger circuit is as good as the conventional chargers which come fitted inside the cars and bikes.

Moreover the circuit can be simply integrated to ones own vehicle if the feature is not originally available in the vehicle.

Alternatively one may think of manufacturing the present unit and selling them in the market as an automobile cell phone charger and earn some hard bucks.

Circuit Description

Cell phones as we all know are highly sophisticated gadgets by nature and when it comes to charging cell phones the parameters no doubt also needs to be of very high standards.

The AC/DC cell phone chargers which come with the cell phones are all SMPS based and are extremely good with their outputs and that’s why the cell phone gets so efficiently charged by them.

However if we try to make our own version, it may fail altogether and the cell phones may just not respond to the current and display a “not charging” on the screen.

Cell phone battery cannot just be charged by supplying DC 4 volts, unless the current is optimally dimensioned the charging won’t initiate.

Using voltage regulator IC for making a DC to DC charger, which I myself have discussed in one of my earlier article is a good approach, but the IC tends to become too hot while charging the cell phone battery and therefore requires adequate heatsinking for remaining cool and operative.

This makes the unit a bit bulkier and moreover some significant amount of power is wasted in the form of heat, so the design cannot be considered very efficient.

The present PWM controlled DC to DC cell phone charger circuit is outstanding in its respect because, the involvement of PWM pulses helps to keep the output very suitable to the cell phone circuitry and also the concept involves no heating of the output device, making the entire circuit truly efficient.

Looking at the circuit we find that again the work horse IC 555 comes to our rescue and performs the important function of generating the required PWM pulses.

The input to the circuit is supplied through some standard DC source, ideally from an automobile battery.

The voltage powers the IC which instantly starts generating the PWM pulses and feeds it to the components connected at its output pin #3.

At the output the power transistor is used for switching the DC voltage at its collector directly to the cell phone.

However only the average DC voltage is finally fed to the cell phone due to the presence of the 100uF capacitor, which effectively filters the pulsating current and provides a stable, standard 4 volts to the cell phone.

After the circuit is built, the two pots will need to be optimized perfectly so that a well dimensioned voltage  is produced at the output which may be ideally suited for charging the cell phone.   

Parts List

R1, R2, R3 = 1K,

P1, P2 = 47K,

C2 = 1n,

C3, C1 = 100uF/25V

IC1 = 555

D1, D2, D3 = 1N4007
T1 = TIP127

Do you believe in the existence of ghosts? Well some of you may answer positively while some may just nod their heads showing sheer skepticism regarding the issue. Whatever may be the reactions; nobody just can’t deny or ignore the responses delivered from the circuit explained in this article. Here we are discussing a super simple yet super sensitive paranormal activity sniffer circuit, which can be effectively and possibly used for detecting ghosts or similar supernatural existence within a range of 10 meters. Many of these circuits may be built and posted at definite intervals for securing a certain premise having a large area. The circuit incorporates an alarm at the output which sounds immediately on detecting a paranormal intrusion. The circuit is ideally suited for areas that are prone to ghosts or likely of getting infested with similar para-natural sneakers.

WARNING 1 – THE DEVICE HAS BEEN TESTED WITH POSITIVE RESULTS AND IS PROVED TO BE EXTREMELY ACCURATE WITH THE DISCUSSED DETECTIONS. FOLKS WITH WEAK HEARTS OR TENDER PERSONALITY ARE ADVISED NOT TO GO ABOUT WITH THIS DEVICE, BECAUSE THE DEVICE NOT ONLY DETECTS BUT ALSO COINCIDENTALLY HAS THE ABILITY OF ATTRACTING THE PARABEINGS.  

WARNING 2 – THE DEVICE CAN BE TESTED IN MORGUES, GRAVEYARDS, cemeteries etc. ZOMBIES ARE THE ONES WHICH ARE INSTANTLY DETECTED BY THIS DEVICE EVEN FROM DISTANCES MORE THAN 50 METERS. NO DOUBT CREATURE LIKE ZOMBIES WILL HATE THIS DEVICE….BEWARE.

Concept

It has been found through experiments by many researchers that paranormal occupancy is strongly accompanied by RF disturbances ranging from a few Hertz to many Kilohertz. 

These signals may be directly proportional to the hostile nature of the ghost. Zombies are found to be emitting the strongest signals and are therefore considered the most horrible among the lot.

The circuit of a ghost detector discussed here is typically configured for capturing the above RF emissions from these creatures and transforming them into more human understandable electronic indications.

Circuit Description

A single versatile IC 324 is involved in the whole operation.

The IC is a quad opamp IC, meaning four opamps in one package.

 Referring to the figure, the opamps can be seen configured as hi gain non inverting amplifiers.

All the opamps are configured as high gain signal amplifiers.

Tiny electromagnetic or RF disturbances which are typically found being generated during the presence of ghosts or paranormal activities are instantly picked up by the antenna of the circuit and are fed to the input of the first opamp stage at pin #9.

The signals get instantly amplified and are transferred to the subsequent stages for further amplification and enhancement.

The output of the last opamp is connected to an opto-coupler.

The optocoupler is a homemade type, incorporating an LED and an LDR fixed such that their emitting and detecting surfaces are placed face to face inside a light proof enclosure.

Here, the optocoupler is used for sensing the LED illumination that may occur when a certain paranormal activity is sensed. 

The illumination produced over the LED is tracked by the LDR whose resistance falls with the LED light. 

The fall in the resistance of the LDR activates the connected transistor at the output, which in turn actuates a buzzer or a horn indicating a possible ghost intrusion.

The whole circuit may be built over a small piece of vero-board and should be strictly operated with a 9 volt battery.

The whole system may be enclosed inside a plastic box with the antenna kept protruding out of the box.

Parts List

R1 = 100K,

R2 = 2M2,

R3, R4 = 1K,
C1 = 0.01uF ceramic

OP1 = LED/LDR assembly inside a light proof enclosure,

T1 = BC557,

B1 = Piezo Electric Buzzer

READERS ARE REQUESTED TO SHARE THEIR EXPERIENCES WITH THIS DEVICE. A PHOTO OR A VIDEO PROOF WILL BE GREATLY APPRECIATED....