first project, but for a client

Thread Starter

devoided

Joined Apr 2, 2021
17
I'm making a signboard with leds.

First project I'm going into, although the problem, (I'm still learning), is that I don't know which lead will hold the DC live wire, coming from the bridge rectifier below, straight to the resistor before touching any led bulb.

The bottom most lead, below the K, is +. Topmost, above 6, is -ve. I figure these are AC input leads.

The middle ones are bringing me a halt. The symbols for both are ~ and ~. Where does the DC live go, and DC neutral go?

IMG_20210430_112326_202.jpg
 

boostbuck

Joined Oct 5, 2017
59
The bottom most lead, below the K, is +. Topmost, above 6, is -ve. I figure these are AC input leads.

The middle ones are bringing me a halt. The symbols for both are ~ and ~. Where does the DC live go, and DC neutral go?
You have figured incorrectly.

The ~ pins are for AC input, and the + and - pins are the rectified DC output. Conventionally the + pin would be thought of as DC live, but where you put components such as current-limit resistors depends on the circuit purpose and configuration.
 

BobaMosfet

Joined Jul 1, 2009
1,854
I'm making a signboard with leds.

First project I'm going into, although the problem, (I'm still learning), is that I don't know which lead will hold the DC live wire, coming from the bridge rectifier below, straight to the resistor before touching any led bulb.

The bottom most lead, below the K, is +. Topmost, above 6, is -ve. I figure these are AC input leads.

The middle ones are bringing me a halt. The symbols for both are ~ and ~. Where does the DC live go, and DC neutral go?

View attachment 237142
IMHO You're in over your head already by not knowing how to look at a bridge rectifier that converts AC to DC. Not poking at you- just making you notice the inherent WARNING involved. Your lack of knowledge can get you seriously hurt if working with MAINS (or any) higher voltages and currents. I wouldn't use this if MAINS related.

AT A MINIMUM!!! - Put a fuse in, on the either AC lead that will pop if you short a connection. Do something to protect yourself.

First thing- get a datasheet and _understand_ it. We're here to help: Here is for that family of Bridge Rectifier. You need to understand that this component also needs components around it to help function properly.

Get this- it will help you:

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3
 

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MisterBill2

Joined Jan 23, 2018
9,308
It is a bit of fraud to represent that you know how to do something when you do not know how to do it. In fact it is quite dishonest if you are taking money to provide what you are not able to provide.
 

strantor

Joined Oct 3, 2010
5,646
It is a bit of fraud to represent that you know how to do something when you do not know how to do it. In fact it is quite dishonest if you are taking money to provide what you are not able to provide.
I would agree with others that OP seems a bit in over his head, but this is taking it too far. You don't know who OP is, who the client is, the details of the agreement, or what assurances were given to the client. This could be a 12y/o making a project for his aunt. Or it could be a 50 y/o person who was given a shot by a friend to do something with full understanding that it was something new. Or you could be right. But to make that assumption and throw turds at strangers is a dick move.

Besides, ever heard "fake it til you make it?" That's the underlying theme of just about every American business success story .
 

strantor

Joined Oct 3, 2010
5,646
@devoided I've just read your previous thread so I have an understanding where you're coming from. For your first LED sign project I would recommend skipping the power supply design and just buy an LED power supply. It could (but probably not*) cut into your profits a bit, but the time you'll save by skipping the power supply design learning curve is... well, time is money when you're in business, and I think the value of the time saved would eclipse any other potentially lost revenue from buying an off-the-shelf supply.

*Most electronics, especially these kinds, come from China, where people are paid so little that you can buy the finished product often for less than the price of the components to build it yourself.

Give an idea of what kind of LEDs and how many you want to use, and we can recommend a power supply.
 

AnalogKid

Joined Aug 1, 2013
9,362
Also, if you are selling something that plugs into the wall, don't even ***think*** about building the power supply yourself unless you have power supply design experience, product safety experience, and liability insurance. Even though I and the company I worked for had all of those things, my house was in my wife's name only until 2 years after I retired.

ak
 

BobaMosfet

Joined Jul 1, 2009
1,854
Also, if you are selling something that plugs into the wall, don't even ***think*** about building the power supply yourself unless you have power supply design experience, product safety experience, and liability insurance. Even though I and the company I worked for had all of those things, my house was in my wife's name only until 2 years after I retired.

ak
This should be a plaque on the wall of everybody who invents- Liability, liability, liability. And not always due to poor product. Remember the fools who tried to trim a hedge with a lawnmower by holding it up by the skirt around the blade??? Darwin-awards have many, many similar examples.
 

Thread Starter

devoided

Joined Apr 2, 2021
17
There is no polarity for the AC input, the ~ pins are interchangeable.

Could you post a schematic or wiring diagram so people can give it a quick look for safety and sanity checks?
it's for rectifying power for LEDs to be connected in series. so, no need for a wiring diagram
 

AnalogKid

Joined Aug 1, 2013
9,362
it's for rectifying power for LEDs to be connected in series. so, no need
So, you're wrong.

Paraphrasing Rear Admiral Joshua Painter: "Engineers don't take a dump, son, without a schematic."


Think for a moment. You literally don't know which end is up (which pins are inputs and which ones are outputs), yet you think you can get advice about an electronic circuit, with lethal voltages, ***without*** any drawing of any kind?

Really?

ak
 

Thread Starter

devoided

Joined Apr 2, 2021
17
OK, I highly appreciate your feedback guys. I'll send the diagram tomorrow, but for clarification, I emulated some people who made it seem easy, that is, making LED signs in series. An example of what I'm doing, for elaboration

For example, lets say I have 100 red leds for my sign. I was thinking, use the rectifier to turn 240v AC into 240v DC. I should now find the value of the resistor to use. My guide (he makes these signs, but located a little far away from me) said regardless of LEDs color, they calculate with an average voltage of 2v per 5mm LED. So, with this, the resistor value is 1.6k or higher. With the 100 red LED bulbs, "in my head", this sign is complete.

For this project, i have to do the sign with a couple hundred LEDs.

So, that's my setup/rundown. What could go wrong?
 

Yaakov

Joined Jan 27, 2019
3,523
OK, I highly appreciate your feedback guys. I'll send the diagram tomorrow, but for clarification, I emulated some people who made it seem easy, that is, making LED signs in series. An example of what I'm doing, for elaboration

For example, lets say I have 100 red leds for my sign. I was thinking, use the rectifier to turn 240v AC into 240v DC. I should now find the value of the resistor to use. My guide (he makes these signs, but located a little far away from me) said regardless of LEDs color, they calculate with an average voltage of 2v per 5mm LED. So, with this, the resistor value is 1.6k or higher. With the 100 red LED bulbs, "in my head", this sign is complete.

For this project, i have to do the sign with a couple hundred LEDs.

So, that's my setup/rundown. What could go wrong?
YOU COULD DIE OR SOMEONE ELSE COULD

JUST TO BE CLEAR WHAT YOU ARE PROPOSING IS DANGEROUS AND WRONG
 

Thread Starter

devoided

Joined Apr 2, 2021
17
Nothing could go wrong indeed since it's complete in your head. Follow your guide, you're in good hands.
don't be sarcastic, I meant what I said

That's why I said in my head since I'm a complete beginner with no small beginner projects I've done
 

Yaakov

Joined Jan 27, 2019
3,523
After seeing the gravity of my project! I've drawn the schematic asap.
So here's the problem, you are potentially exposing people to lethal voltages. What you should do is design your sign, then count up the LEDs you are going to use and figure out the colors (which may matter for voltages), then show us here how many LEDs of what color you want to use.

We can help you power them safely.

Seriously, 240V is very, very dangerous. You need to do this right for it to be safe. Some people here are likely to be upset with your naïve approach, but even they will help you if you are willing to do it properly.

Let's start over, present the problem—the number of LEDs and type(s) you need to power, and let us help you.
 
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