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Copy edited (e.g. ref. <https://en.wiktionary.org/wiki/divider#Noun> and <https://en.wikipedia.org/wiki/Sentence_clause_structure#Run-on_sentences>). Added some context.
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JRE
JRE
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The value of 140 mW is not its rated power; it is just its nominal power dissipated at the nominal voltage. It is completely fine to operate the coil directly from 5 V DC, as long as 5 V DC is within the coil's rating.

Actually, if you place a resistor in series, you form a resistor divider that drops your coil voltage too much and the relay may never switch the contacts.

The only reason I would think of for you to want to place a resistor in series is if you want to operate the coil directly from a microcontroller's digital output. I strongly advise not to do that. Digital pins are not meant to drive inductive loads. Use a simple BJT driver rated at the coil current. And, and don't forget the flyback diode!.

The value of 140 mW is not its rated power; it is just its nominal power dissipated at the nominal voltage. It is completely fine to operate the coil directly from 5 V DC, as long as 5 V DC is within the coil's rating.

Actually, if you place a resistor in series, you form a resistor divider that drops your coil voltage too much and the relay may never switch the contacts.

The only reason I would think of for you to want to place a resistor in series is if you want to operate the coil directly from a microcontroller's digital output. I strongly advise not to do that. Digital pins are not meant to drive inductive loads. Use a simple BJT driver rated at the coil current. And don't forget the flyback diode!

The value of 140 mW is not its rated power; it is just its nominal power dissipated at the nominal voltage. It is completely fine to operate the coil directly from 5 V DC, as long as 5 V DC is within the coil's rating.

Actually, if you place a resistor in series, you form a resistor divider that drops your coil voltage too much and the relay may never switch the contacts.

The only reason I would think of for you to want to place a resistor in series is if you want to operate the coil directly from a microcontroller's digital output. I strongly advise not to do that. Digital pins are not meant to drive inductive loads. Use a simple BJT driver rated at the coil current, and don't forget the flyback diode.

Copy edited (e.g. ref. <https://en.wiktionary.org/wiki/divider#Noun> and <https://en.wikipedia.org/wiki/Sentence_clause_structure#Run-on_sentences>). Added some context.
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edit approved Nov 23, 2023 at 15:50
Peter Mortensen
edit approved Nov 23, 2023 at 15:50
Peter Mortensen
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The value of 140mW140 mW is not its rated power,power; it is just its nominal power dissipated at the nominal voltage. It is completely fine to operate the coil directly from 5VDC5 V DC, as long as 5VDC5 V DC is within the coil's rating.

Actually, if you place a resistor in series, you form a resistor dvididerdivider that drops your coil voltage too much and the relay may never switch the contacts.

The only reason I would think of for you to want to place a resistor in series is if you want to operate the coil directly from a microcontroller's digital output. I strongly advise not to do that. Digital pins are not meant to drive inductive loads. Use a simple BJTBJT driver rated at the coil current. And don't forget the flyback diodeflyback diode!

The value of 140mW is not its rated power, it is just its nominal power dissipated at the nominal voltage. It is completely fine to operate the coil directly from 5VDC, as long as 5VDC is within the coil's rating.

Actually, if you place a resistor in series, you form a resistor dvidider that drops your coil voltage too much and the relay may never switch the contacts.

The only reason I would think of for you to want to place a resistor in series is if you want to operate the coil directly from a microcontroller's digital output. I strongly advise not to do that. Digital pins are not meant to drive inductive loads. Use a simple BJT driver rated at the coil current. And don't forget the flyback diode!

The value of 140 mW is not its rated power; it is just its nominal power dissipated at the nominal voltage. It is completely fine to operate the coil directly from 5 V DC, as long as 5 V DC is within the coil's rating.

Actually, if you place a resistor in series, you form a resistor divider that drops your coil voltage too much and the relay may never switch the contacts.

The only reason I would think of for you to want to place a resistor in series is if you want to operate the coil directly from a microcontroller's digital output. I strongly advise not to do that. Digital pins are not meant to drive inductive loads. Use a simple BJT driver rated at the coil current. And don't forget the flyback diode!

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Leonardo Márquez
Leonardo Márquez
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The value of 140mW is not its rated power, it is just its nominal power dissipated at the nominal voltage. It is completely fine to operate the coil directly from 5VDC, as long as 5VDC is within the coil's rating.

Actually, if you place a resistor in series, you form a resistor dvidider that drops your coil voltage too much and the relay may never switch the contacts.

The only reason I would think of for you to want to place a resistor in series is if you want to operate the coil directly from a microcontroller's digital output. I strongly advise not to do that. Digital pins are not meant to drive inductive loads. Use a simple BJT driver rated at the coil current. And don't forget the flyback diode!