Showing posts with label e. Show all posts
Showing posts with label e. Show all posts
Sunday, September 25, 2016
Standard Resistor E series Values
Standard Resistor E series Values
The resistor’s values which are provided to them fall within a category of standard or preferred resistor values.
By: S. Prakash
The values present within the standard resistor category are in sequence which is logarithmic and are in correspondence to the accuracy of the component.
This enables the values present within the standard resistor category to be placed in respect to the tolerance which is present on the component.
The application of these values present within the standard resistor category can be done for other resistors, components, and capacitors as well.
Since the manufacturing of the component values including values of the resistors cannot be done exactly, a specific tolerance value is associated with each and every resistor.
The typical tolerance values associated with the resistors can be ±5%, ±10%, and ±20%. Apart from these tolerance values, there is availability of the tolerance value of ±2% as well.
A list has been made consisting of the standard resistor values and the preferred values in order to ensure and enable the selection of the standard values from the available set of manufacturers.
Thus, this enable the manufacturing of the resistors to be an easy process along with the reduction of the inventory of the manufacturers for the stock holdings by having and following only the range of resistor values which come under the preferred range.
This area has garnered a lot of attraction since there is a requirement of special values of high precision.
The E-series is used by the resistors in order to space and place the common resistor values in correspondence to their respective tolerance levels.
The E-series used is the series for the preferred or standard values. The resistors are placed in such a manner that the spacing is done in order to avoid the overlapping of the tolerance band’s bottom and one value of the tolerance band with the next band and value of the tolerance band.
For example, in case of a resistor of 1 Ohm value and ±20% tolerance level; the resistor will have 1.2 Ohms value of the tolerance band at the bottom if the component’s actual resistor is placed at the tolerance band’s top.
In another example, where a resistor of 1.5 Ohm value and ±20% tolerance level; the resistor will have 1.2 Ohms value of the tolerance band at the bottom if the component’s actual resistor is placed at the tolerance band’s top.
Thus, one can build a series through the calculation of the values for a wide range in the manner elaborated in the above two examples. This calculation and building of series is done at the interval of every ten years.
The series for the standard values of the resistor which is generated through the process elaborated above is known as the E-series and the values generated are known as the preferred values.
One of the most basic series is the E3 series within the range of E series and consists of three values which are namely 4.7, 1.0, and 2.2.
Since the tolerance associated with the resistors is very wide, the frequency with which this is used for the current day applications is very less. But the basic values of the resistor are used widely in order to reduce their stock holding.
The other series within the range of the E-series is the E6 series whose values are calculated at the interval of every ten years and consists of six values for a tolerance level of ±20%.
The other series within the range of the E-series are the E12 and E24 series whose values are calculated at the interval of every ten years and consists of twelve and twenty-four values for a tolerance level of ±10% and ±5% respectively.
The other series such as the E96 and E48 series within the range of E-series are also available but they are not very common.
In most of the resistors, there is availability of the E12 and E6 series. But this is not true for the E24series since its tolerance series is very close and thus the E24series are mostly found in the resistors whose tolerance levels are very high.
Thus, the resistors for which the E24series are commonly used in the current day include the metal oxide film resistors along with the other types.
The E24 series is rarely used for the carbon type resistors, the availability of which is again scarce. This is because the carbon type resistors have tolerance ranges at very low level since there is no guarantee of their values to a tolerance level which is so close.
The standard and preferred resistor ranges of the E-series are used in a wide range and thus have been adopted by various different manufacturing organizations as a standard.
For example, the preferred values of the E series have been adopted by the North American organization, “Electrical Industries Association (EIA)”.
The system which is used for the resistors for the standard component values adoption works very efficiently.
This can be equally applied for the resistor’s other components. Another way which is applicable consists of the concept of the values enlisted in the standard list to be used and which in turn are determined by the component’s tolerance levels.
The capacitors also use the preferred values of the E series which includes the series such as –E3 which are of the lower order.
The capacitors which have low tolerance level use the E6 series of the E series. The tolerance level of the electrolytic capacitors is very wide in range.
On the other hand, the tolerance levels of the ceramic capacitors are very high, higher than that of the electrolytic capacitors and thereby they can use the values of the E24 and E12 series as well.
For example, the component such as the Zener diodes also follow the preferred values of the E series of EIA for breakdown voltages of theirs.
The standard voltage of the Zener diodes conforms to the voltage values of the E24 and E12 series. This is especially true for the level of 5 volts where Zener diode is of the value of 5.1 Volts.
By: S. Prakash
The values present within the standard resistor category are in sequence which is logarithmic and are in correspondence to the accuracy of the component.
This enables the values present within the standard resistor category to be placed in respect to the tolerance which is present on the component.
The application of these values present within the standard resistor category can be done for other resistors, components, and capacitors as well.
Since the manufacturing of the component values including values of the resistors cannot be done exactly, a specific tolerance value is associated with each and every resistor.
The typical tolerance values associated with the resistors can be ±5%, ±10%, and ±20%. Apart from these tolerance values, there is availability of the tolerance value of ±2% as well.
A list has been made consisting of the standard resistor values and the preferred values in order to ensure and enable the selection of the standard values from the available set of manufacturers.
Thus, this enable the manufacturing of the resistors to be an easy process along with the reduction of the inventory of the manufacturers for the stock holdings by having and following only the range of resistor values which come under the preferred range.
This area has garnered a lot of attraction since there is a requirement of special values of high precision.
Standard Resistor Values and their E-series
The E-series is used by the resistors in order to space and place the common resistor values in correspondence to their respective tolerance levels.
The E-series used is the series for the preferred or standard values. The resistors are placed in such a manner that the spacing is done in order to avoid the overlapping of the tolerance band’s bottom and one value of the tolerance band with the next band and value of the tolerance band.
For example, in case of a resistor of 1 Ohm value and ±20% tolerance level; the resistor will have 1.2 Ohms value of the tolerance band at the bottom if the component’s actual resistor is placed at the tolerance band’s top.
In another example, where a resistor of 1.5 Ohm value and ±20% tolerance level; the resistor will have 1.2 Ohms value of the tolerance band at the bottom if the component’s actual resistor is placed at the tolerance band’s top.
Thus, one can build a series through the calculation of the values for a wide range in the manner elaborated in the above two examples. This calculation and building of series is done at the interval of every ten years.
The series for the standard values of the resistor which is generated through the process elaborated above is known as the E-series and the values generated are known as the preferred values.
One of the most basic series is the E3 series within the range of E series and consists of three values which are namely 4.7, 1.0, and 2.2.
Since the tolerance associated with the resistors is very wide, the frequency with which this is used for the current day applications is very less. But the basic values of the resistor are used widely in order to reduce their stock holding.
The other series within the range of the E-series is the E6 series whose values are calculated at the interval of every ten years and consists of six values for a tolerance level of ±20%.
The other series within the range of the E-series are the E12 and E24 series whose values are calculated at the interval of every ten years and consists of twelve and twenty-four values for a tolerance level of ±10% and ±5% respectively.
The other series such as the E96 and E48 series within the range of E-series are also available but they are not very common.
In most of the resistors, there is availability of the E12 and E6 series. But this is not true for the E24series since its tolerance series is very close and thus the E24series are mostly found in the resistors whose tolerance levels are very high.
Thus, the resistors for which the E24series are commonly used in the current day include the metal oxide film resistors along with the other types.
The E24 series is rarely used for the carbon type resistors, the availability of which is again scarce. This is because the carbon type resistors have tolerance ranges at very low level since there is no guarantee of their values to a tolerance level which is so close.
The standard and preferred resistor ranges of the E-series are used in a wide range and thus have been adopted by various different manufacturing organizations as a standard.
For example, the preferred values of the E series have been adopted by the North American organization, “Electrical Industries Association (EIA)”.
The standard and preferred values of various other components
The system which is used for the resistors for the standard component values adoption works very efficiently.
This can be equally applied for the resistor’s other components. Another way which is applicable consists of the concept of the values enlisted in the standard list to be used and which in turn are determined by the component’s tolerance levels.
The capacitors also use the preferred values of the E series which includes the series such as –E3 which are of the lower order.
The capacitors which have low tolerance level use the E6 series of the E series. The tolerance level of the electrolytic capacitors is very wide in range.
On the other hand, the tolerance levels of the ceramic capacitors are very high, higher than that of the electrolytic capacitors and thereby they can use the values of the E24 and E12 series as well.
For example, the component such as the Zener diodes also follow the preferred values of the E series of EIA for breakdown voltages of theirs.
The standard voltage of the Zener diodes conforms to the voltage values of the E24 and E12 series. This is especially true for the level of 5 volts where Zener diode is of the value of 5.1 Volts.
Available link for download
Saturday, August 27, 2016
Solar E Rickshaw Circuit
Solar E Rickshaw Circuit
The post explains a simple solar electric rickshaw or E rickshaw circuit which can easily built by anybody at home and used with a locally fabricated vehicle. The idea was requested by Mr. Amit.
The Request
dear sir, i will enough grateful to if you can provide me the complete circuit for e rickshaw with solar system along with complete electronic component value, please send it to amit46vm@yahoo.com/gmail.com regards amit
The Design
In one of my earlier posts I presented an idea which could be effectively used for making an electric scooter using a BLDC motor and associated circuitry.
In this post we discuss a similar concept but without using BLDC motor just for the sake of simplicity.
Although using an ordinary brushed motor could appear to be inefficient compared to its BLDC counterpart, a brushed motor nevertheless eliminates the need of complex BLDC driver circuitry and the involved complicated wiring with the motor making the design extremely simple and layman friendly.
Moreover, a brushed motor can be operated by using an ordinary IC 555 PWM circuit, quite unlike a BLDC motor which requires much sophisticated control ICs which are not only difficult to find in the market, but are always vulnerable of becoming obsolete, risking the guarantee period of a E-rickshaw which might have incorporated that particular chip.
A simple PWM circuit using IC 555 can be used for controlling the speed of the E-rickshaw by controlling the speed of its attached control motor.
The PWM concept makes sure that the energy consumption of the motor is significantly reduced and the efficiency is increased to the maximum possible range.
The 100k pot associated with the two 1N4148 diodes becomes responsible for varying the output PWMs at pin#3 of the IC, which in turn determines the conduction rate of the TIP142 transistor and the speed of the connected motor. For higher current, the TIP142 could be replaced with equivalently rated mosfet.
The 100uF capacitor at the base of the transistor makes sure that whenever the E-rickshaw is initiated, it delivers a slow soft start to the motor, rather than with a jerk or at a higher initial torque.
The potentiometer should be of very high quality so that it is able to sustain the frequent speed control operations and may last for many many years without going through fatigue or mechanical wear and tear.
Typical specifications of the pot should be as given under:
Made up of Cermet or carbon moulded element.
Approved by BS and CECC
Rated at 2 watt at 70 degrees C, in Cermet
Rugged construction
Military standard layout
Container sealed with MC1/MH1 standards
Stiff, silver plated terminals.
The speed control pot knob could be favorably installed in the handle of the E rickshaw, near the thumb of the driver, so that controlling the speed of the rickshaw could be executed with maximum ease, and minimum effort.
The ON/OFF switch of the circuit should be also accessible near the thumb of the driver installed on the handle, so that the driver is able to switch OFF the system immediately during a critical or a catastrophic circumstance.
Th braking mechanism of the proposed electric rickshaw could be built using the conventional technique, however it must include a push-switch which may be in series with the supply voltage to the motor circuit, and must be configured in such a way that when brakes are applied the switch is first deactivated, switching OFF power to the IC 555 circuit and the motor.
This makes sure that before the braking system hits the wheel axle, the motor is disabled first preventing its interference in the braking procedure.
In order to convert the proposed E rickshaw into a power saving solar electric rickshaw, a solar panel may be integrated with the system, as explained below:
Although primarily the battery of the vehicle will need to be charged from an AC mains operated charger quite often, the solar panel will act like a secondary back up charger, and help reduce electric consumption of the vehicle which in turn will help to save power and money for the end user.
Preferably the solar panel could be mounted on the roof of the vehicle and therefore could be as big as the size of the roof top of the E rickshaw, and rated at around 30V, 5 amps which looks quite economical for the proposed system.
With the above specified solar panel, no additional charger controller would be required as the voltage from the panel would automatically self adjust with the 24V battery specs, making the unit even more cost effective.
The solar integration ensures that the vehicle battery is kept on a topped-up condition whenever the vehicle is idling and thus help to increase the efficiency of the vehicle substantially.
For a resonable three seater E rickshaw including the driver, a 24V 20 amp motor would be just enough (assumed value), and to operate this motor optimally throughout the day, a 24V 200AH battery would do just well, although the user could alter the AH specs according to the needs and suitability of the vehicles operational schedule.
The Request
dear sir, i will enough grateful to if you can provide me the complete circuit for e rickshaw with solar system along with complete electronic component value, please send it to amit46vm@yahoo.com/gmail.com regards amit
In one of my earlier posts I presented an idea which could be effectively used for making an electric scooter using a BLDC motor and associated circuitry.
In this post we discuss a similar concept but without using BLDC motor just for the sake of simplicity.
Although using an ordinary brushed motor could appear to be inefficient compared to its BLDC counterpart, a brushed motor nevertheless eliminates the need of complex BLDC driver circuitry and the involved complicated wiring with the motor making the design extremely simple and layman friendly.
Moreover, a brushed motor can be operated by using an ordinary IC 555 PWM circuit, quite unlike a BLDC motor which requires much sophisticated control ICs which are not only difficult to find in the market, but are always vulnerable of becoming obsolete, risking the guarantee period of a E-rickshaw which might have incorporated that particular chip.
A simple PWM circuit using IC 555 can be used for controlling the speed of the E-rickshaw by controlling the speed of its attached control motor.
The PWM concept makes sure that the energy consumption of the motor is significantly reduced and the efficiency is increased to the maximum possible range.
The 100uF capacitor at the base of the transistor makes sure that whenever the E-rickshaw is initiated, it delivers a slow soft start to the motor, rather than with a jerk or at a higher initial torque.
The potentiometer should be of very high quality so that it is able to sustain the frequent speed control operations and may last for many many years without going through fatigue or mechanical wear and tear.
Typical specifications of the pot should be as given under:
Made up of Cermet or carbon moulded element.
Approved by BS and CECC
Rated at 2 watt at 70 degrees C, in Cermet
Rugged construction
Military standard layout
Container sealed with MC1/MH1 standards
Stiff, silver plated terminals.
The speed control pot knob could be favorably installed in the handle of the E rickshaw, near the thumb of the driver, so that controlling the speed of the rickshaw could be executed with maximum ease, and minimum effort.
The ON/OFF switch of the circuit should be also accessible near the thumb of the driver installed on the handle, so that the driver is able to switch OFF the system immediately during a critical or a catastrophic circumstance.
The Brakes
Th braking mechanism of the proposed electric rickshaw could be built using the conventional technique, however it must include a push-switch which may be in series with the supply voltage to the motor circuit, and must be configured in such a way that when brakes are applied the switch is first deactivated, switching OFF power to the IC 555 circuit and the motor.
This makes sure that before the braking system hits the wheel axle, the motor is disabled first preventing its interference in the braking procedure.
Solar Panel Integration
In order to convert the proposed E rickshaw into a power saving solar electric rickshaw, a solar panel may be integrated with the system, as explained below:
Although primarily the battery of the vehicle will need to be charged from an AC mains operated charger quite often, the solar panel will act like a secondary back up charger, and help reduce electric consumption of the vehicle which in turn will help to save power and money for the end user.
Preferably the solar panel could be mounted on the roof of the vehicle and therefore could be as big as the size of the roof top of the E rickshaw, and rated at around 30V, 5 amps which looks quite economical for the proposed system.
With the above specified solar panel, no additional charger controller would be required as the voltage from the panel would automatically self adjust with the 24V battery specs, making the unit even more cost effective.
The solar integration ensures that the vehicle battery is kept on a topped-up condition whenever the vehicle is idling and thus help to increase the efficiency of the vehicle substantially.
The Battery
For a resonable three seater E rickshaw including the driver, a 24V 20 amp motor would be just enough (assumed value), and to operate this motor optimally throughout the day, a 24V 200AH battery would do just well, although the user could alter the AH specs according to the needs and suitability of the vehicles operational schedule.
Available link for download
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