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Optocoupler driving a relay

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ewandeur

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4n35+relay

Please,

Can I use a 4N35 to drive a 6V relay directly, or I will need to use another transistor to make an interface ?

Tkx
 

relay using 4n35

ewandeur said:
Can I use a 4N35 to drive a 6V relay directly, or I will need to use another transistor to make an interface ?
You will probably need another transistor because, given the current transfer ratio of the 4N35, you will not be able to pump enough current into the LED to get sufficient output current from the phototransistor to drive the relay. It really depends on the relay's activation current, however.
 

    ewandeur

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using 4n35 to drive a relay

Well I have driven a 6V/200Ω relay using BC107A.You can try it too.
 

    ewandeur

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4n35 optocoupler relay driving

it all depends on the resistance of the relay and voltage applied...basically the current
needed to drive the relay ....if it is less like 50 -100Ω use a general purpose transistor like bc547 bc147(max 150mA-.5A)....in darlington mode...or else if it is still less use 2n3055
 

    ewandeur

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h ehe he he eh !
The current need big or small ??? If big, you should use buffers as Darlington as ULN2803, . . . . . and if small, you can use 4N35 (<50mA).
Good luck for U !
 

    ewandeur

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I think you dont have to couple another transistor since the maximum forward current of 4N35 is more than enough to turn on the relay. but since you have small voltage about 6V, its better to check the specs of your relay..
 

    ewandeur

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see these links about relays
**broken link removed**
**broken link removed**

Bibin John
www.bibinjohn.tk
 

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