LED doorbell

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jrsevt
 
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LED doorbell

Post by jrsevt »

I bought one your LED buttons (ID 560) to replace a doorbell. I have a 16V AC transformer and LEDs like DC for no flicker. I did some research and have a bridge rectifier, capacitor and resistor. The recommended resistor when using 12-24V DC is 470 ohm but I am going to use a 1K ohm because DC peak is 1.4x that of AC. I also read that a capacitor can be used to smooth the current.

I have enclosed my drawing and wondering if the wiring is correct. I plan installing the components in a 1" x 3" metal box that the doorbell face plate would screw in to.

Bridge rectifier is KL-410 4A, resistor 1K ohm and 47 uF 25V capacitor.

I want the LED to be always light and button to be normally open and closed when pressing to activate chime. I'll also add a 1A fuse on the LED DC, which goes where?

Thanks!
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Drawing1.jpg
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adafruit_support_rick
 
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Re: LED doorbell

Post by adafruit_support_rick »

I think your cap is backwards. You should have + to +.
Also, make sure you use a 1/2W resistor.

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jrsevt
 
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Re: LED doorbell

Post by jrsevt »

Thanks. I failed to mention my resistor is 1W, so I'll pick up a 0.5W one. You are correct on the capacitor orientation.

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adafruit_support_rick
 
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Re: LED doorbell

Post by adafruit_support_rick »

Oh! 1W is even better. I meant a *minimum* of 1/2W.

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Franklin97355
 
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Re: LED doorbell

Post by Franklin97355 »

my resistor is 1W
one watt is better you don't need to replace it.

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jrsevt
 
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Re: LED doorbell

Post by jrsevt »

Great!

Thanks.

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jrsevt
 
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Re: LED doorbell

Post by jrsevt »

Here is my modified drawing if anyone might like to duplicate this. My old light on doorbell button burnt out and I wanted something that looked nicer but didn't want to spend $50+ for something like a Spore LED doorbell button, which is plastic and apparently fades and becomes brittle in direct sunlight. Also have limited space next to my door and so I made a faceplate. I took a piece of 3/16" aluminum plate and cut to 4" x 2", drilled a 5/8" hole in the center and drilled and countersunk the screw holes to fit over a box. I sanded the faceplate I made with 400, 600, 800 and 1000 grit sheet sandpaper taped to a flat surface. Then applied aluminum polish to make it as reflective as a mirror.

The ID 560 weatherproof LED button looks to be just what I was looking for and all components are inexpensive to put this together. Also, a fun project that educates how electronic components work.

Most doorbell transformers convert 120V AC to 16V AC. LEDs work best with DC so not to flicker. The bridge rectifier converts AC to DC. The capacitor smooths out the current and the resistor reduces the current so the LED doesn't burn out. I did no calculations for sizing the components. I just did some searches for recommendations. Those of you who might be studying for an EE degree will think this is basic 101 but my background is in chemistry - a long time ago.
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Drawing1.jpg
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