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Help about relays

frankilische

Apr 29, 2011
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Good day house, please i am trying to build a little relay switch connection and am a bit confused about the connections.....the relay in question has 4 terminals , the positive , negative and two others .... i want to power it using a DC battery and i want a switch along the line to operate the circuit with, determining when to power on and off the relay. The relay is supposed to control a small DC fan motor....How do i go about it please, i need to know how to link up the battery, the switch and the DC fan motor.........Thank you
 

davenn

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Sep 5, 2009
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hi there welcome

BUT in future, please dont post the same Q in multiple places, as ppl dont know which thread to respond to and keep all the info in one place.

really easy will draw a digram for you ...

attachment.php


Dave
 

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frankilische

Apr 29, 2011
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Sorry about that, i just joined today. I am a newbie, so please pardon me. Thanks for the response and really appreciate the time taken. Looking forward to the diagram. Thanks once again.
 

davenn

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things to consider.....

what is your battery voltage,
what is the relay's coil voltage rating

why are you using a relay to switch on the motor instead of directly from the battery ?

Dave

PS If the relay is actually marked + and - that infers it already has a diode across the coil
 

frankilische

Apr 29, 2011
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things to consider.....

what is your battery voltage,
what is the relay's coil voltage rating

why are you using a relay to switch on the motor instead of directly from the battery ?

Dave

The battery voltage is 12V, the relay is 5V, i was hoping to incorporate a delay in the fan motor so it does not just come on immediately the switch is turned on. What is your advice on this?.Thanks for the time
 

davenn

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The battery voltage is 12V, the relay is 5V, i was hoping to incorporate a delay in the fan motor so it does not just come on immediately the switch is turned on. What is your advice on this?.Thanks for the time

well you cant put 12V into a 5V relay coil, you are going to burn it out, you need 5V for activating the relay. The relay isnt going to add any significant turnon delay.

post a pic of the relay close and sharp so Ican see the marking on it and confirm its ratings :)

Dave
 

davenn

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ok here's a relay delay cct
Ohhh a relay wouldnt normally have that wide a voltage rating

That relay in the link has NO built in delay
Again I need to know the voltage rating of the relay YOU have in front of you the data sheet shows they are available in 4 ratings 5V, 6V, 12V and 24V which one do you have ?

attachment.php


with the 47k and the 100uF values the delay is ~ 7 sec reducing the resistor value from 47k will reduce the delay

Dave
 

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frankilische

Apr 29, 2011
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Thanks so much for this Dave, well, i don't have the relay here as at now, would have to check up for precision tomorrow. Assuming the relay coil is 12V, would that circuit diagram do the trick??...and i guess i have to connect the fan motor to the other end of the relay right???
 

davenn

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CRAP!! :(

in the middle of our chat, I lost internet. It hadnt come back after 1/2 an hour so the wife and I went to the movies

yes thats correct,
and the fan motor what is it's voltage and current requirements, is it an AC or DC motor ?
how are you going to supply power to it ?
tell me that and I will modify that diagram for to :)


Dave
 
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awt

Mar 14, 2011
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"...to operate the circuit with, determining when to power on and off the relay." seems not clear. Did you mean a switch that turn 'on' or 'off' depends on certain condition or an ordinary switch that needs you to turn it 'on' or 'off'? You don't even need relay, but if it for experimentation and you insist on using relay, the below shows that simple connection.
relay-fan-ckt.GIF
 

davenn

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Sorry about the Internet, i pulled out the fan motor from the vacuum cleaner in this site........http://www.maplin.co.uk/12v-high-power-portable-vacuum-cleaner-227621.......i would have to power it directly from the 12V, 3.3Ah battery....its a DC motor.....Thanks so much for the support. I really appreciate....

edit the link in your post its unuseable as it stands I think you have your "i" at the end of the link that should be outside the URL tab as its part of your next sentence eg ...

i would have to .....

Dave
 

frankilische

Apr 29, 2011
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yeah.......i think that's better, i only brought down the rest part of the URL.....so if u want to access it, just use it as one long URL.....thanks so much
 
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