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Soldering directly to a CNY 70 reflective sensor. Answered

 Has anybody been successful at soldering directly to a CNY 70 Reflective sensor.
This is the second one i have killed.
I am thinking next time i should use a socket.
It is a hack for a rotary encoder on a little gear motor.

In the pic the blue wire is ground, red wire 5v and white wire is signal.

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steveastrouk
steveastrouk

Best Answer 8 years ago

Too much solder, too much heat.

There is ZERO need to do mechanical joints with modern solders. Just lightly tin both halves of the joint, and then quickly fuse them together - it should take less than 3 seconds to do.

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WWC
WWC

Answer 8 years ago

Mechanical joint. Does that mean how i have them overlapped?
Your saying to connect them butted together?

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steveastrouk
steveastrouk

Answer 8 years ago

LAPPING'S fine, but it looks like you've invested some time in WRAPPING the wires together ?

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WWC
WWC

Answer 8 years ago

I looked at my heat and it is at 370c. Somewhat high for this application?
I think 350c is a standard temp?
I don't typically wrap wires but in this case it helped them stay together for soldering.

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steveastrouk
steveastrouk

Answer 8 years ago

370 sounds VERY hot. More like 280 ! 60/40 melts at less than 200 C.

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WWC
WWC

Answer 8 years ago

Yes i agree i should of checked that before.

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steveastrouk
steveastrouk

Answer 8 years ago

Not a problem, but you only have 0.3 seconds to do the joint.....

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Jayefuu
Jayefuu

Answer 8 years ago

Your lapping them over is fine. In the first picture the 220 ohm resistor connection to it is about ideal. There's minimal solder

If I were doing it, to reduce the amount of heat and time soldering I would pre tin 4 wires and then very quickly solder them to the pins, like steve said, it should take seconds. Tin the wire, then reheat the tinned wire then apply to the leg.

I'd then insulate them all with some heat shrink to make sure nothing can short out. Due to the fact that the legs on that thing are single core, too much poking around and bending can cause them to snap. This is why I'd extend the leads 10 cm THEN connect the resistors and pins together as you have in your diagram. It should let you connect it all together without heating up the device too much or stressing the pins.

James

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WWC
WWC

Answer 8 years ago

My first one i made like this. The resistors were at the other end. I still had the grounds bent into the center and connected to one wire tho.

I use the tin both wires the first method.
This first one was subjected to soldering, heat for the heat shrink then hot glue.
A lot of heating times.

i am leaning towards a socket next time. No heat, no stressed pins!

06.bmp
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steveastrouk
steveastrouk

Answer 8 years ago

I'd prefer to put the stiffed leads all in one place, where they are unlikely to get moved.

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WWC
WWC

Answer 8 years ago

Such as a socket?

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WWC
WWC

8 years ago

Steve and jayefuu answers and comments were both correct and on track.
So i guess i will have to give best answer steve, he was the first one out of the shoot.
Thanks for the help.

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Jayefuu
Jayefuu

8 years ago

I checked your wiring against the CNY70 data sheet, you have it wired correctly, I thought perhaps you'd mistaken the top view and bottom view but your pictures show your wiring is correct.

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WWC
WWC

Answer 8 years ago

Thanks