Showing posts with label a. Show all posts
Showing posts with label a. Show all posts
Sunday, May 19, 2013
How to Test a Electric Motor
Electrical motor is the fashionable utilized in business in each single place the arena.It essential tool to made manufacturing smoothly.To be sure that the electricalal motor situation is just right or now not,we should understand tips on how to trying out it.
The electrician or maintenance particular person should have this skill to decide the electrical motor situation,defected or can not use anymore.It can save the repair value and upkeep expenditure.
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The electrician or maintenance particular person should have this skill to decide the electrical motor situation,defected or can not use anymore.It can save the repair value and upkeep expenditure.
- Check the appearance of motor.find any defect at body,cooling fan or shaft.
- Try to swing manually the rotor shaft test the bearing condition.Check both it smooth rotating or now not.
- Collect the motor data from motor NAME PLATE.It crucial to know about specs of motor prior to we trying out.
- Ensure the terminal for power supply in good condition.Check the connection bar for terminal ( U,V,W ).What more or less connection for terminal.( STAR OR DELTA ).
- Please ascertain first the facility supply VOLTAGE for electric motor.It single phase or three section sort.
- Using the multimeter,check the continuity of winding from segment to phase ( U to V,V to W ,W to U ).Each section to segment should have a continuity if winding is OK.
- Check the motor winding ohms studying the use of multimeter or ohmmeter for phase to phase terminal ( U to V,V to W ,W to U ).Reading for each and every phase should related inside one or two ohms deference.If no studying,maybe winding was once defect.
- Check the insulation resistance of motor winding using Insulation checker meter on 500 Volt scale.First check from segment to segment ( U to V,V to W ,W to U ) and 2d check from segment to earthing ( U to E,V to E ,W to E ).According to straightforward IEEE 43: IR check minimum value of the electrical motor is a 1 Mega Ohm ( 1 MΩ ) . It imply winding is in excellent condition.Refer my ultimate publish find out how to check motor the use of insulation take a seem ater meter.
- After all step we perform and the testing result's OK,now we check in actual situation.Why we take a appear at it with energy supply?It is to be certain that no mechanical defect like bearing downside or unbalance rotor movement.
- When motor is working,we should examine the AMPERE of motor using Clamp on meter.Refer to FLA at name plate of motor.
- If each step is completed,now we are able to come to a decision the situation of electrical motor either OK or NEED TO REPAIR.
Friday, April 12, 2013
Electronic Fuse Employs A Relay
The hobby circuit below uses an unusual method to generate about 12,000 volts with about 5uA of current. Two SCRs form two pulse generator circuits. The two SCRs discharge a 0.047uF a 400v capacitor through a xenon lamp trigger coil at 120 times a second.
The high voltage pulses produced at the secondary of the trigger coil are rectified using two 6KV damper diodes. The voltage doubler circuit at the secondary of the trigger coil charges up two high voltage disc capacitors up to about 12KV. Although this circuit can’t produce a lot of current be very careful with it. A 12KV spark can jump about 0.75 of an inch so the electronic circuit needs to be carefully wired with lots of space between components.
Source by : Streampowers
Wednesday, April 10, 2013
Build A Split Supply Generator
Occasionally a designer needs a dual power supply to power a circuit that is operating with signals near or at ground but the only available supply is a single polarity, usually positive. Many excellent IC solutions are available but a suitable solution for many projects may be constructed from "junk box" parts. The simple circuit below will generate about 9 volts and -4 volts from a single 5 volt supply with sufficient current to power a simple op-amp circuit. The positive voltage drops to about 7 volts when supplying 7 mA and the negative voltage drops to about 3.5 volts when supplying 3.5 mA (1k loads). Although this isnt exactly a +- 15 volt supply, this is plenty of voltage and current for many op-amp circuits and will allow the output of most op-amps to swing below zero volts and will allow most op-amp inputs to measure voltages below zero volts. This circuit uses the CD4049 which is a high current version of the CD4069 which will also work with somewhat lower current capability.
Split Supply Generator Circuit Diagram
The two inverters on the left generate a square wave and the other four inverters are connected in parallel to increase the current drive to the diodes. The diode on top clamps the voltage on the top capacitor at about 4.5 volts when the inverters go low. When the inverters go high, their output voltage is added to the 4.5 volts to give about 9.5 volts. The second diode rectifies this voltage to give a little over 9 volts on the output. The bottom two diodes work in the same way only the voltage on the first capacitor is clamped to about 0.5 volts on the positive swing and then goes down to about -4.5 volts on the negative swing of the inverters, giving about -4 volts out.
The prototype is operating at only 500 Hz to allow for the use of some old-fashioned germanium rectifiers that I have in large numbers. If more modern schottky rectifiers are used the frequency may be set higher by lowering the .001uF capacitor or the 1 megohm resistors. The 4, 330 uF capacitors are larger than necessary and a few uF will suffice if the frequency is raised to, say, 5 kHz (try 100k resistors or a 100pF capacitor). Yep, I have a lot of those 330 uF capacitors, too. In fact, I have a few thousand of the CD4049, if you would like a few. (charles@wenzel.com)
This little circuit is going into a sub-picoampere leakage meter for characterizing JFETs and other components for extremely high impedance circuits.
Monday, April 8, 2013
How to make a Simple Infra Red Remote Control Circuit
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 many other domestic equipment like a water pump, lights etc we are compelled to walk around for implementing the switching.
The article is inspired by our usual TV remote concept and has been applied for controlling other house hold electrical appliances remotely. The circuit facilitates and helps the user to do the operations without moving an inch from his resting place.
The whole circuit of the proposed IR remote control may be understood by studying the following points:
Referring to the figure, we see that the entire layout consists of just a couple of stages viz: the IR sensor stage and the fkip flop stage.
Thanks to the highly versatile, miniature IR sensor unit which forms the heart of the circuit and directly coverts the received IR waves from the tranamitter unit into the relevant logic pulses for feeding the fllip flop stage.
The sensor basically consists of just three leads viz: the input, the output and the biasing voltage input lead. The involvmant of only three leads makes the unit very easy to configure into a practical circuit.
The sensor is specified for operating at 5 volts regulated voltage which makes the inclusion of the 7805 IC stage important. The 5 voltage supply also becomes useful for the flip flop IC 4017 and is appropriately supplied to the relevant stage.
When a IR signal becomes incident over the sensor lens, the inbuilt feature of the unit activates, triggering a sudden drop in its output voltage.
The PNP transistor T1 responds to the negative trigger pulse from the sensor and quickly pulls the positive potential at its emitter to the collector across the resistor R2.
The potential developed across R2 provides a positive logic high to the IC 4017 input pin #14. The IC instantly flips its output and changes it’s polarity.
The transistor T2 accepts the command and switches the relay according to the relevant input provided to its base.
The relay thus switches the connected load across its contacts alternately in response to the subsequent triggers received from the IR transmitter unit.
For the sake of convenience the user may use the existing TV remote control set unit as the transmitter for operating the above explained control circuit.
The referred sensor is well compatible with all normal TV or DVD remote control handset and thus can be appropriately switched through it.
The entire circuit is powered from an ordinary transformer/bridge network and the entire circuit may be housed inside a small plastic box with the relevant wires coming out of the box for the desired connections.
Parts List
The following parts will be required for making the above explained infra red remote control circuit:
R1, R3 = 100 ohms,
R2 = 100K,
R4 = 4K7,
R5 = 10K,
C1, C2, C4= 22uF/25V,
C6 = 4.7uF/25V,
C3 = 0.1, CERAMIC,
C5 = 1000uF/25V,
T1 = BC557B
T2 = BC547B,
ALL DIODES ARE = 1N4007,
IR SENSOR = TSOP1738 image: Vishay
IC1 = 4017,
IC2 = 7805,
TRANSFORMER = 0-12V/500mA,
Prototype image courtesy: Raj Mukherji
Saturday, March 23, 2013
How to Make a 220V to 110V Converter Circuit
Primarily there are two AC mains voltage levels that are specified by countries across the globe. These are 110V and 220V. The USA works with a 110V AC mains domestic line while European countries and many Asian countries supply a 220V AC to their cities. Folks procuring imported gadgets from a foreign region having a different mains voltage specs find it difficult to operate the equipment with their AC outlets because of the huge difference in the required input levels.
Though there are 220V to 110V converters available for solving the above issue, these are big, cumbersome and immensely costly.
The present article explains s few interesting concepts which can be possibly implemented for making compact, transformerless 220V to 110V converter circuits.
The proposed homemade converters can be customized and dimensioned as per the gadget size so that these may be inserted and accommodated right inside the particular gadget. This feature helps to get rid of the big and bulky converters and helps to keep away from the unnecessary mess.
CAUTION: ALL THE CIRCUITS DISCUSSED HERE HAVE POTENTIALS OF CAUSING SEVERE LIFE AND FIRE HAZARDS, EXTREME CAUTION IS ADVISED WHILE GETTING INVOLVED WITH THESE CIRCUITS.
All these circuit diagram have been developed by me, lets learn how they can be constructed at home and how the circuit functions:
Using Only Diodes
The first circuit will convert a 220V AC input to any desired output level from 100V to 220V, however the output will be a DC, so this circuit may be used for operating a foreign equipment which might be employing an AC/DC SMPS input power supply stage. The converter will not work with equipment incorporating a transformer at its input.
As we all know that a normal diode, like a 1N4007 drops 0.6 to 0.7 volts across it, when a DC is applied, means that many diodes put in series would drop the relevant amount of voltage across them.
In the the proposed design, in all 190 1N4007 diodes have been used and put in series for acquiring the desired level of voltage conversion.
If we multiply 190 by 0.6, it gives around 114, so thats pretty close to the required mark of 110V.
However since these diodes require an input DC, four more diodes are wired up as a bridge network for the initially required 220V DC to the circuit.
The maximum current that can be drawn from this converter is not more than 300 mA, or around 30 watts.
Using a Triac/Diac Circuit
The next option presented here has not been tested by me, but looks good to me, however many will find the concept dangerous and very undesirable.
I designed the following converter circuit only after doing a thorough research regarding the involved issues and have confirmed it to be safe, but its my personal point of view, if you find it undesirable better do not try this.
The circuit is based on the regular light dimmer switch circuit principle, where the input phase is chopped at the particular voltage marks of the rising AC sine wave. Thus the circuit can be used for setting the input voltage at the required 100 V level.
One big issue involved with this circuit is back EMF that might be generated from the transformer of the gadget, this might instantly fry the triac or the diac. Although sufficiently advanced and high power components have been included in the design, an effective snubber circuit stage was felt imperative and therefore the RC network across the triac has been stationed.
The pot shown in the circuit should be adjusted for obtaining the required 110V at the output terminals.
A 500 watt iron element coil resistance may be introduced in series with the load for extra safety.
Alternatively a simpler version of the circuit can be made, where the main high triac is operated via a cheap light dimmer switch for the intended results.
Using an Autotransformer Cocept
The last circuit in the order is perhaps the safest from the above because it uses the conventional concept of transfering power through magnetic induction, or in other words here we employ the age old autotransformer concept for making the desired 110V converter.
However here we have the freedom of designing the core of the transformer such that it can be stufed inside the particular gadget enclosure which needs to be operated from this converter. There will be always some space in gadgets like an amplifier or other simlar systems, which allows us to measure the free spave inside the gadget and customize the core design.
I have shown the use of ordinary steel plates here as the core material which are stacked together and bolted across two of the sets.
The bolting of the two sets of lamination provides some sort of looping effect, generally required for efficient magnetic induction across the core. The winding a single long winding from start to end, as shown in the figure. The center tap from the winding will provide the required approximate 110 V AC output.
Though there are 220V to 110V converters available for solving the above issue, these are big, cumbersome and immensely costly.
The present article explains s few interesting concepts which can be possibly implemented for making compact, transformerless 220V to 110V converter circuits.
The proposed homemade converters can be customized and dimensioned as per the gadget size so that these may be inserted and accommodated right inside the particular gadget. This feature helps to get rid of the big and bulky converters and helps to keep away from the unnecessary mess.
CAUTION: ALL THE CIRCUITS DISCUSSED HERE HAVE POTENTIALS OF CAUSING SEVERE LIFE AND FIRE HAZARDS, EXTREME CAUTION IS ADVISED WHILE GETTING INVOLVED WITH THESE CIRCUITS.
All these circuit diagram have been developed by me, lets learn how they can be constructed at home and how the circuit functions:
Using Only Diodes
The first circuit will convert a 220V AC input to any desired output level from 100V to 220V, however the output will be a DC, so this circuit may be used for operating a foreign equipment which might be employing an AC/DC SMPS input power supply stage. The converter will not work with equipment incorporating a transformer at its input.
As we all know that a normal diode, like a 1N4007 drops 0.6 to 0.7 volts across it, when a DC is applied, means that many diodes put in series would drop the relevant amount of voltage across them.
In the the proposed design, in all 190 1N4007 diodes have been used and put in series for acquiring the desired level of voltage conversion.
If we multiply 190 by 0.6, it gives around 114, so thats pretty close to the required mark of 110V.
However since these diodes require an input DC, four more diodes are wired up as a bridge network for the initially required 220V DC to the circuit.
The maximum current that can be drawn from this converter is not more than 300 mA, or around 30 watts.
Using a Triac/Diac Circuit
The next option presented here has not been tested by me, but looks good to me, however many will find the concept dangerous and very undesirable.
I designed the following converter circuit only after doing a thorough research regarding the involved issues and have confirmed it to be safe, but its my personal point of view, if you find it undesirable better do not try this.
The circuit is based on the regular light dimmer switch circuit principle, where the input phase is chopped at the particular voltage marks of the rising AC sine wave. Thus the circuit can be used for setting the input voltage at the required 100 V level.
One big issue involved with this circuit is back EMF that might be generated from the transformer of the gadget, this might instantly fry the triac or the diac. Although sufficiently advanced and high power components have been included in the design, an effective snubber circuit stage was felt imperative and therefore the RC network across the triac has been stationed.
The pot shown in the circuit should be adjusted for obtaining the required 110V at the output terminals.
A 500 watt iron element coil resistance may be introduced in series with the load for extra safety.
Alternatively a simpler version of the circuit can be made, where the main high triac is operated via a cheap light dimmer switch for the intended results.
Using an Autotransformer Cocept
The last circuit in the order is perhaps the safest from the above because it uses the conventional concept of transfering power through magnetic induction, or in other words here we employ the age old autotransformer concept for making the desired 110V converter.
However here we have the freedom of designing the core of the transformer such that it can be stufed inside the particular gadget enclosure which needs to be operated from this converter. There will be always some space in gadgets like an amplifier or other simlar systems, which allows us to measure the free spave inside the gadget and customize the core design.
I have shown the use of ordinary steel plates here as the core material which are stacked together and bolted across two of the sets.
The bolting of the two sets of lamination provides some sort of looping effect, generally required for efficient magnetic induction across the core. The winding a single long winding from start to end, as shown in the figure. The center tap from the winding will provide the required approximate 110 V AC output.
Friday, March 22, 2013
Making a 40 Watt LED Emergency Tubelight Circuit Using 1 Watt 350 mA LEDs
The article explains a simple yet effective 40 watt LED emergency tube light circuit which can be installed at home for acquiring uninterruptible illumination at the same time saving a lot of electricity and money.
You might have reads one of my earlier articles which explained a 40 watt LED street light system. The power saving concept is pretty much the same, through a PWM circuit, however the alignment of the LEDs has been laid in a completely different manner here.
As the name suggest the present idea is of an LED tube light and therefore the LEds have been configured in a straight horizontal pattern for better and efficient light distribution.
The circuit also features an optional emergency battery back up system which may be employed for getting an uninterruptible illumination from the LEDs even during the absence of normal mains AC. Due to the PWM circuit the acquired backup can extend up to more than 25 hours on every single recharge of the battery (rated at 12V/25AH).
The PCB would be strictly needed for assembling the LEDs. The PCB must be an aluminum-back type. The track layout is shown in the below given picture. As can be seen the LEDs are spaced at a distance of about 2.5 cm or 25mm from each other for enhancing maximum and optimal distribution of light.
Either the LEDs may be laid over a single row or over a couple of rows.
A single row pattern is shown in the below given layout, due to lack of space only two series/parallel connection has been accommodated, the pattern is continued further on the right side of the PCB so that all the 40 LEDs become included.
Normally the proposed 40 watt LED tube light circuit, or in other words the PWM circuit may be powered through any standard 12V/3amp SMPS unit for the sake of compactness and decent looks.
After assembling the above board, the output wires should be connected to the below shown PWM circuit, across the transistor collector and positive. The supply voltage should be provided from any standard SMPS adapter as mentioned in the above section of the article. The LED trip will instantly light up illuminating the premise with flood light brightness. The illumination may be assumed to be equivalent to a 40 watt FTL with power consumption of less than 12 watts, thats a lot of power saved.
Emergency Battery Operation
If an emergency backup is preferred for the above circuit, it may be simply done by adding the following circuit.
Lets try to understand the design in more details:
The circuit shown above is the PWM controlled 40 watt LED lamp circuit, the circuit has been elaborately explained in this article. You can refer it for knowing more about its circuit functioning.
The next figure shown below is an automatic under voltage and over voltage battery charger circuit with automatic relay changeovers. The whole functioning may be understood with the following points:
The IC 741 has been configured as a low/high battery voltage sensor and it activates the adjoining relay connected to the transistor BC547 appropriately.
Assume the mains to be present and the battery to be partially discharged. The voltage from the AC/DC SMPS reaches the battery through the N/C contacts of the upper relay which remains in an deactivated position because of the battery voltage which may be below the full charge threshold level, lets assume the full charge level to be 14.3V (set by the 10K preset).
Since the lower relay coil is connected to the SMPS voltage, stays activated such that the SMPS supply reaches the PWM 40 watt LED driver via the N/O contacts of the lower relay.
Thus the LEDs remains switched ON by using the DC from the mains operated SMPS adapter, also the battery continues to get charged as explained above.
Once the battery gets fully charged, the output of the IC741 goes high, activating the relay driver stage, the upper relay switches and instantly connects the battery with the N/C of the lower relay, positioning the battery in the standby condition.
However until AC mains is present, the lower relay is unable to deactivate and therefore the above voltage from the charged battery is not able to reach the LED board.
Now if suppose AC mains fails, the lower relay contact shifts to the N/C point, instantly connects the supply from the battery to the PWM LED circuit, illuminating the 40 watt LEDs brightly.
The LEDs consume battery power until either the battery falls below the low voltage threshold or mains power is restored.
The low battery threshold setting is done by adjusting the feedback preset 100K across the pin3 and pin6 of the IC741.
You might have reads one of my earlier articles which explained a 40 watt LED street light system. The power saving concept is pretty much the same, through a PWM circuit, however the alignment of the LEDs has been laid in a completely different manner here.
As the name suggest the present idea is of an LED tube light and therefore the LEds have been configured in a straight horizontal pattern for better and efficient light distribution.
The circuit also features an optional emergency battery back up system which may be employed for getting an uninterruptible illumination from the LEDs even during the absence of normal mains AC. Due to the PWM circuit the acquired backup can extend up to more than 25 hours on every single recharge of the battery (rated at 12V/25AH).
The PCB would be strictly needed for assembling the LEDs. The PCB must be an aluminum-back type. The track layout is shown in the below given picture. As can be seen the LEDs are spaced at a distance of about 2.5 cm or 25mm from each other for enhancing maximum and optimal distribution of light.
Either the LEDs may be laid over a single row or over a couple of rows.
A single row pattern is shown in the below given layout, due to lack of space only two series/parallel connection has been accommodated, the pattern is continued further on the right side of the PCB so that all the 40 LEDs become included.
Normally the proposed 40 watt LED tube light circuit, or in other words the PWM circuit may be powered through any standard 12V/3amp SMPS unit for the sake of compactness and decent looks.
After assembling the above board, the output wires should be connected to the below shown PWM circuit, across the transistor collector and positive. The supply voltage should be provided from any standard SMPS adapter as mentioned in the above section of the article. The LED trip will instantly light up illuminating the premise with flood light brightness. The illumination may be assumed to be equivalent to a 40 watt FTL with power consumption of less than 12 watts, thats a lot of power saved.
Emergency Battery Operation
If an emergency backup is preferred for the above circuit, it may be simply done by adding the following circuit.
Lets try to understand the design in more details:
The circuit shown above is the PWM controlled 40 watt LED lamp circuit, the circuit has been elaborately explained in this article. You can refer it for knowing more about its circuit functioning.
The next figure shown below is an automatic under voltage and over voltage battery charger circuit with automatic relay changeovers. The whole functioning may be understood with the following points:
Assume the mains to be present and the battery to be partially discharged. The voltage from the AC/DC SMPS reaches the battery through the N/C contacts of the upper relay which remains in an deactivated position because of the battery voltage which may be below the full charge threshold level, lets assume the full charge level to be 14.3V (set by the 10K preset).
Since the lower relay coil is connected to the SMPS voltage, stays activated such that the SMPS supply reaches the PWM 40 watt LED driver via the N/O contacts of the lower relay.
Thus the LEDs remains switched ON by using the DC from the mains operated SMPS adapter, also the battery continues to get charged as explained above.
Once the battery gets fully charged, the output of the IC741 goes high, activating the relay driver stage, the upper relay switches and instantly connects the battery with the N/C of the lower relay, positioning the battery in the standby condition.
However until AC mains is present, the lower relay is unable to deactivate and therefore the above voltage from the charged battery is not able to reach the LED board.
Now if suppose AC mains fails, the lower relay contact shifts to the N/C point, instantly connects the supply from the battery to the PWM LED circuit, illuminating the 40 watt LEDs brightly.
The LEDs consume battery power until either the battery falls below the low voltage threshold or mains power is restored.
The low battery threshold setting is done by adjusting the feedback preset 100K across the pin3 and pin6 of the IC741.
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