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Topic: Connect my led strips (12v) to arduino  (Read 7379 times) previous topic - next topic

KeketteStyle

Hello guys, I am beginner at electronics.. I am building a scoreboard for my baseball team and i would like to connect my 7 segments to a shift register.

I success to use shift register and make shine 8 leds one by one. My circuit is :

(https://www.instructables.com/id/8-LED-Knightrider-Using-Shift-Registers-With-Ardui/).

theses leds are on 5v

Now I want to replace these 8 leds by my 7 segments (12v and 1 segment = 6 leds).
So I connect my 12v jack on arduino and I replace pin 5v to Vin. Then I add transistor to connect my segment but it doesn't work... My circuit :

(on this picture,my jack is off, but trust me, i tried !)

I am using the same arduino code as above.

Where is my mistake ?

Wawa

Use a shift register that can switch 12volt/150mA.
Like the TPIC6B595 (ebay).

This page might interrest you.
Leo..

KeketteStyle

#17
Jul 21, 2018, 01:17 pm Last Edit: Jul 21, 2018, 01:28 pm by KeketteStyle
ouch price is expensive !
I saw some projects using shift register 74HC595 to their score board (also with 12v leds).
https://www.instructables.com/id/Remote-Controlled-Arduino-Scoreboard-using-LED-Str/

Can you help me to use this shift register (74HC595) with my leds 12v ??

Wawa

ouch price is expensive !
 
I saw some projects using shift register 74HC595 to their score board (also with 12v leds). Can you help me to use this shift register (74HC595) with my leds 12v ??
Do you call $0.50 for a TPIC6B595 expensive?

Sure, you can use the 74HC595, but you have to add a transistor to each output.
That could get messy and expensive.
Leo..

KeketteStyle

I talked about SparkFun Large Digit Driver :p

I got already 74HC595 and transistor TIP120. With this shift register, I have to use 5v for shift register and 12v for leds ?

Wawa

Ahh, I see this is a cross-post.

https://forum.arduino.cc/index.php?topic=556791.0

Cross-posters are time wasters.
I'm out.

KeketteStyle

#21
Jul 21, 2018, 02:35 pm Last Edit: Jul 21, 2018, 02:37 pm by KeketteStyle
Before to use Ir remote, actually I got USB cable to power my arduino (5v) also my shift register. And I got a power supply (12v) for my leds. I wonder, why I could have not only 1 power : both for my arduino and leds ??

how it looks ?

ReverseEMF

#22
Jul 21, 2018, 06:06 pm Last Edit: Jul 21, 2018, 06:07 pm by ReverseEMF
Before to use Ir remote, actually I got USB cable to power my arduino (5v) also my shift register.
What does the IR Remote have to do with 5V power from your USB cable?

And I got a power supply (12v) for my leds. I wonder, why I could have not only 1 power : both for my arduino and leds ??
If what you're asking is "Why can't I use my 12V supply to also power my Arduino?" 

The short answer is "You can."

The long answer is:

An official Arduino [can't vouch for clones] can easily take 12V.  Just connect it to the Power Jack [either with a plug {get the polarity right}, OR solder it on to the board {get the polarity right}].

BUT, because the LEDs will use a fair amount of current, you need to take care in your power connections.  Safest way is to run separate Power and Ground wires to each thing you are powering.  So, separate wires to the Arduino, and separate [fatter] wires to the LED string.
"It's a big galaxy, Mr. Scott"

Please DON'T Private Message to me, what should be part of the Public Conversation -- especially if it's to correct a mistake, or contradict a statement!  Let it ALL hang out!!

KeketteStyle

Thanks you ! I never plugged power jack (12v) because I was affraid to fry my arduino lol

Thanks a lot ! Actually I am using Transistor TIP120 (for each segment) and shift register 74HC595. I want to make my circuit more simple. What do you think about TPIC6B595 ? Someone said "he's big brother of 74HC595". It can replace both tip120 and 74HC595 ?

ReverseEMF

#24
Jul 21, 2018, 11:32 pm Last Edit: Jul 21, 2018, 11:39 pm by ReverseEMF
What do you think about TPIC6B595 ? Someone said "he's big brother of 74HC595". It can replace both tip120 and 74HC595 ?
I've never used a TPIC6B595, but from the datasheet I see that each output can source up to 150mA continuous, and 500mA pulsed [Pulse duration ≤ 100 μs and duty cycle ≤ 2%] at up to 50V, so if your LED strips can be driven by that, then Whoo-Hoo! 

Check out Figure 6 and Figure 7 on the Texas Instruments datasheet: http://www.ti.com/lit/ds/symlink/tpic6b595.pdf

As for logic compatibility, I don't see anything in the datasheet [cursory look] that claims pin-for-pin or logic compatibility with the 74HC595, so, perhaps pull up each datasheet and do a comparison?  It is a serial to parallel shift register with an output latch, so it's at least the same functionality.  And it seems to have the same control pins [again cursory look].  So, it sounds like you're in business.
"It's a big galaxy, Mr. Scott"

Please DON'T Private Message to me, what should be part of the Public Conversation -- especially if it's to correct a mistake, or contradict a statement!  Let it ALL hang out!!

Paul__B

Thanks you! I never plugged power jack (12v) because I was afraid to fry my Arduino lol
It should not damage it - as long as you mean 12 V from a regulated 12 V supply, and not 13/6 V or a car battery.  If you connect anything more than a few TPIC6B595s to the 5 V however, it will likely overheat and shut down intermittently.  It would be better to use one of the switchmode "buck" regulators readily available to feed proper 5 V to the Arduino via its 5 V terminal.

What do you think about TPIC6B595? Someone said "he's big brother of 74HC595". It can replace both tip120 and 74HC595 ?
See reply #11.  Given you are using only two of the three LED sections which will draw just 120 mA for each segment, the TPIC6B595 is the perfect solution.

I've never used a TPIC6B595, but from the datasheet I see that each output can source up to 150mA continuous
Rubbish!

CrossRoads

Yes. TPIC6B595 for 150mA current loads per each output.
If you need even more, than TPIC6A595, 350mA outputs.

Both can only sink current - so 12V to the + of the strip, the - of the strip goes to the TPIC output which acts as a switch to Gnd.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Coding Badly


@KeketteStyle, please do not cross-post.  Threads merged.


ReverseEMF

#28
Jul 22, 2018, 09:40 pm Last Edit: Jul 22, 2018, 09:51 pm by ReverseEMF
If you connect anything more than a few TPIC6B595s to the 5 V however, it will likely overheat and shut down intermittently.  It would be better to use one of the switchmode "buck" regulators readily available to feed proper 5 V to the Arduino via its 5 V terminal.
I'm probably misreading this, but if you are saying that the 5V regulator on the Arduino board, can't drive more than a few TPIC6?595s?  If so, consider that [from the datasheet] ICC MAX is 5mA and TYP 0.5mA, then, at a conservative 100mA max from the Arduino regulator, that's 100mA/5mA = 20, worst case.  In other words, at least 20 TPIC6?595s can be powered by the Arduino 5V regulator.  And, possibly even more, since the regulator current limits at 500mA.  So, it would be a matter of heat caused by dissipation due to drop out voltage. [Unless we're talking about something other than an UNO -- wasn't able to determine, for sure]

See reply #11.  Given you are using only two of the three LED sections which will draw just 120 mA for each segment, the TPIC6B595 is the perfect solution.
Rubbish!
Why "Rubbish"?  According to the datasheet, even if ALL of the Drains are sinking the Absolute Maximum 150mA continuously, is acceptable for less than "extended periods".  So, 120mA on one or more Drains, even simultaneously should be just fine if intermittent enough.  90mA is the Recommended Nominal.  So, does "Rubbish" refer to this?
"It's a big galaxy, Mr. Scott"

Please DON'T Private Message to me, what should be part of the Public Conversation -- especially if it's to correct a mistake, or contradict a statement!  Let it ALL hang out!!

Paul__B

So, does "Rubbish" refer to this?
Read more closely - and then read CrossRoads' answer.  :smiley-roll:

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