Relay

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Hi Eric

Can't open 'Relay basic pdf' (0 views)

Just been wiring some DPDT's up myself, very usful for my alternating slaves!!

Cheers

hi Mark,
I have noticed for a while that the pdf's sometime will not download correctly from the Forum, also the Blog.

The way around this is to place the original pdf in a folder before zipping.
I have EDITED the previous post and the relay zip, give it a try, let me know.
 

I saved to a folder on my PC. tried to extract and it's saying cannot as the zip is invalid


Cheers.
 
Hi Eric

Not that I need it but it's always good to be able to open files!!!

Thing I'm more interested in is equaling out two coils of differant ohms in series with eachother (one robbing the supply from the other).

Cheers
 
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This one?

I could view online.

hi Mark,
You should be able to download it from the web.??
I just did from your link., do you have the latest pdf viewer.?

The Foxit Reader is a free download.
 
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Hi Eric

Sory Eric dint make myself clear.I can dwnload ok and open.!!!

So to equal two coils out (within the relay) do I add a suitable resistor across the smaller coil to bring the Ohm's up on that ?????

Cheers

Edit:
say 200ohm verses 13ohm at 24v
 
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hi Mark,
Understood re the pdf.

For your project its OK to pad up the resistance of the relay coil to match an odd voltage pair. Consider the wattage of the resistor.
 
hi Mark,
Understood re the pdf.

For your project its OK to pad up the resistance of the relay coil to match an odd voltage pair. Consider the wattage of the resistor.

Hi Eric

One of these days I will get my head around electronics Math....Funny thing is the two coils in mention the 13ohm will run fine while the 200ohm barley wakes up.
The data on the coils says it pulls 50ma.
How does 50ma convert to ohms? I'm sure I measured the ohms on the coil wrong as its only a small coil-

**broken link removed** 12v version.??

Vasir sorry about muscling in on your thread but it may also answer some of your questions!!!

Cheers
 

hi,
If its 12Vdc at 0.05A that is 12V/0.05 = 240R

Use your DVM to measure the 12V relays coil resistance.
 
Hi Eric

Ok just tested at 243ohm so not far off, the other 13ohm so How can I best bring these together so both work.?

Cheers

hi,
If you plan to connect the two relays in a parallel, you need a 243R - 13R = 230R in series with the 13R coil.

The wattage rating of the resistor will have to be [ at 50mA] W= I^2 * R = 0.05^2 *230R = 0.575W.

That resistor will run HOT at 100% duty, I would use at least a 3Watt.
 
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Hi Eric
The two coils are actually in series so I put a 7W 220R (closest I had) in parallel with the 243R coil and that worked a treat... is this right method??

Cheers
 
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Hi Eric
The two coils are actually in series so I put a 7W 220R (closest I had) in parallel with the 243R coil and that worked a treat... is this right method??

Cheers

hi Mark,
Can you confirm the working voltage of the 13R relay.?
If its 12Vdc then adding a 220R in parallel with a 240R relay coil would be approx 110R.

So the voltage across the 13R coil would only be [13/[123]] * 24 = 2.5V ! and across the 240R coil would be 21.5V. it will cook.!
 

Oh sugar your right

I tested and confirmed your comments

So do I put a series resistor in on the 240R coil as well ?? (430R)?- (R= V/I) 21.5/0,05 ?

Cheers

Edit:

I have 2 coils both in series. 1 coil is 13 ohm and a working current of around 200ma V= I*R= 0.20*13= (2.6v)
the other coil is 240 ohm at 50ma V= I*R= 0.24*50= (12v)
My supply is 24vDC.
 
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wombweller Edit: I have 2 coils both in series. 1 coil is 13 ohm and a working current of around 200ma V= I*R= 0.20*13= (2.6v) the other coil is 240 ohm at 50ma V= I*R= 0.24*50= (12v) My supply is 24vDC.[/QUOTE said:
hi Mark,
I think a diagram would help you best, look at this image.

 
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