Re: “How to test LED screen?”
2. The op-amp and Hexfet there are the overhead voltage very low.
The problem is ICL7611 can't stand DC 340v, I search a lot ICs for this kind of HV appication.
Supply Voltage V+ to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18V
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . V- -0.3 to V+ +0.3V
Differential Input Voltage (Note 1) . . . . . . . . [(V+ +0.3) - (V- -0.3)]V
Duration of Output Short Circuit (Note 2). . . . . . . . . . . . . . Unlimited
I think #47 PIC...
Peter Chiu
Banned
Last Activity: 11-28-2018, 04:33 PM
Joined: 12-04-2012
Location: Mesa Arizona
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Last edited by Peter Chiu; 04-25-2015, 06:46 PM. -
Re: “How to test LED screen?”
Sorry, I thought you were ask everybody.....
Here is something for you to think about, lets say you want to build 100mA constant current source, you have 10VDC power supply and you have a 50 Ohms load resistor that you want to have 100mA of current flows through it, what is the value of the resistor you need to put in series with that 50 Ohms load to give 100mA of current. What is the Voltage drops on the 50 Ohms load resistor?
10v/50ohm=0.2A=200ma what is the value of the resistor you need to put in series with that 50 Ohms...Last edited by Peter Chiu; 04-25-2015, 06:28 PM.Leave a comment:
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Re: “How to test LED screen?”
if circuit pass 10ma @ DC155.6V current limited resistor will be 16k ohm (@ first Pic top-right resistors group #43), and I will use 10k 20k to limited the Total current not over too much...Last edited by Peter Chiu; 04-25-2015, 03:34 PM.Leave a comment:
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Re: “How to test LED screen?”
Simple LED Bulb Circuit
[url]http://www.homemade-circuits.com/2012/04/how-to-make-led-bulb-circuit.html[/url]
5630 SMD LED Driver/Tube light Circuit
[url]http://www.homemade-circuits.com/2013/09/5630-smd-led-drivertube-light-circuit.html[/url]
1 Watt LED Emergency Lamp Circuit Using Li-Ion Battery
[url]http://www.homemade-circuits.com/2013/04/1-watt-led-emergency-lamp-circuit-using.html[/url]
Surge Protected Cheap Transformerless Hi-Watt LED Driver Circuit
[url]http://www.homemade-circuits.com/2012/09/surge-protected-cheap-transformerless-3.html[/url]...Leave a comment:
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Re: “How to test LED screen?”
[music] [url]https://www.youtube.com/watch?v=aH63RKQ7OEw[/url]
How to make triacs and LEDs get along
[url]http://powerelectronics.com/lighting-systems/how-make-triacs-and-leds-get-along[/url]Re: “How to test LED screen?”<br /> ...et-along[/url]Re: “How to test LED screen?”
[music] [url]https://www.youtube.com/watch?v=aH63RKQ7OEw[/url]...Leave a comment:
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Re: “How to test LED screen?”
Thank you for your supporting...
will use 10 points rotary switch, add power resisters together ,so can choice from 1ma, 5ma, 10ma, 20ma, 50ma, 100ma......
If use (1...2....4...8.) In logically, we can get all the value we want ,like 1ma, 4ma, 8ma, 11ma 12ma 13ma....etc......up to 15ma.... use with 4p dip switchs...Last edited by Peter Chiu; 04-25-2015, 10:59 AM.Leave a comment:
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Re: “How to test LED screen?”
[music] [url]https://www.youtube.com/watch?v=_W1_shm7vdE[/url]
Will try this (pic)
The circuit work perfectly,(0V-350V), nothing wrong basically,it's very hard to handle 350v, so I will low down to 110 x 1.14=155.5v , and put first stage current limited resist array for prevention. Or use 1:1 smaller transformer, let it no power to burn anything.... 2.5V x 60= 150V still can test about 60 LEDs (not full brightness)..... See, what's will happen ....Re: “How to test LED screen?”<br /> ..._shm7vdE[/url]...Last edited by Peter Chiu; 04-25-2015, 10:22 AM.Leave a comment:
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[How It's Made] 3D LED Cube, flex led wall, LED curtain.
[How It's Made] 3D LED Cube, flex led wall, LED curtain.
[Music] some videos backgroud musics are terrible, please use this one [url]https://www.youtube.com/watch?v=yM8CFR01KwQ[/url]
Netduino Controlled LED Cube
[url]http://channel9.msdn.com/coding4fun/articles/Netduino-Controlled-LED-Cube[/url]
Outdoor LED Screen teardown (+how to drive LEDs with video)
[url]https://www.youtube.com/watch?v=6iHTbGsnI8Q[/url]
3D LED Cube(32*32*32=32768 pixels)
[url]https://www.youtube.com/watch?v=f1YNyQqbiF0#t=144[/url]
Interactive...Last edited by Peter Chiu; 04-25-2015, 08:51 AM. -
Re: “How to test LED screen?”
change IGBT everything is ok then I bypass the 47k .....everything go back to original.....
the problem is the led burn out right away.....and the IGBT shorted again. because like U said, current limit is very important I just turn a little the voltage up a lot,10 turns controller may be need...
47k maybe important to limit the current ,otherwise the circuit is simple but easy to run wide , I think that's why? that guy put 100k and 12 zener diodes.
I do have IRF740 in stock (we fix car amp) will try it.
When my hand...Last edited by Peter Chiu; 04-24-2015, 06:13 PM.Leave a comment:
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Re: “How to test LED screen?”
[Problem] votage can change from 0V to 350V (DC) but not enough current?
I short the 47k still no enough current . I can't light up 10w LED, stop at dc 7.5V?
can i use 1 ohm? is that Q2 BE reach 0.7 then current limited circuit is on.
I change to 1ohm still the same ,maybe I need to use IRF740
next will change 470k .Maybe R1 not pass enough current ,
Good news change to 1 ohm IGBT shot right away.Last edited by Peter Chiu; 04-24-2015, 05:01 PM.Leave a comment:
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Re: “How to test LED screen?”
You show me, one guy put 100k resistor and 12 zener diodes..
Adjustable voltage 0-354V with my old meter.and 3.3 ohm current limite R need to modified to adjustable . if you have parts, took about an hour to built it .
He said ,I don't believe, so I change 47k look picture..
[The video is belong to my experiment, I have slightly modified the circuit to maintenance 300VDC, I add a 100K resistor in between B+ and 500K , and i add a 24V x 12 = 294V zener parrallel with 500K.
I didn’t use MOSFET because...Last edited by Peter Chiu; 04-24-2015, 04:37 PM.Leave a comment:
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Re: “How to test LED screen?”
[Music] [url]https://www.youtube.com/watch?v=qRlGFXl_e1E[/url]
IGBT i used from this board ( pic 1) U can find any one but Vce>450V
RJP63F3DPP-M0
Silicon N Channel IGBT
High Speed Power SwitchingRe: “How to test LED screen?”<br /> ...ower SwitchingRe: “How to test LED screen?”
...Last edited by Peter Chiu; 04-24-2015, 03:23 PM.Leave a comment:
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Re: “How to test LED screen?”
8.4 V (from 9V battery) , I use the Samsung power board DC12v(marked 13V )
to power the meter.
the cable is AC cable,which I moved away , to have space to hot glue the meter.
the 500k potentiometer I found burned out light dimmer exactly 500k ohm with switch so I can on/off the power....Last edited by Peter Chiu; 04-24-2015, 12:40 PM.Leave a comment:
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Re: “How to test LED screen?”
Update:
I put meter up side down , it's OK, I will change to other one,late.
Shock twice by DC 394 V, now breadboard time.......Leave a comment:
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Re: “How to test LED screen?”
You did not put the LCD back in place correctly or contaminate the connections that is why the digits are missing.
You're right again.... I did put up side down...now ...is ok........ Thanks......
The meter now, I tested on DC12v ..... the transformer is AC 220V to AC 6v, 12v
But this meter only up to DC199.90V so i order another one.
Look carefully I maybe put the reflector the wrong way, too .who care ......I need to keep going on........Last edited by Peter Chiu; 04-24-2015, 10:03 AM.Leave a comment:
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Re: “How to test LED screen?”
PFC is free, come with power board
LED 2 groups 4+3=7
4 strips LEDs each strip has 14 LEDs total on this group LED are 56 LEDs
3 strips LEDs each strip has 14 LEDs total on this group LED are 42 LEDs
7 strips LEDs each strip has 14 LEDs total screen are 98 LEDs
I did light up the screen.
LX27901 is the LED driver IC ,check menu is really helpful.
[url]https://www.google.com/search?q=LX27901&oq=LX27901&aqs=chrome..69i57j0l2j69i59.1324j0j8&sourceid=chrome&es_sm=0&ie=UTF-8[/url]...Leave a comment:
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Re: “How to test LED screen?”
Appreciated for your information.
I came to the office at 5:30 am, I need to modifier 220v (input power) V A meter to dc 12v
and I need to finish this LED tester today, by change to IGBT and some breadboard test and modification.
The prototype look like this (Pics). I call it Mutualism or Parasitism circuits
Bacillary, I will use all my junks to build one.
Yes,LED tester parasite in Samsung 55' LED TV power supply.
An adjustable DC voltage 0-340v ,LED screen tester, with PFC ,IGBT,...Last edited by Peter Chiu; 04-24-2015, 08:30 AM.Leave a comment:
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Re: “How to test LED screen?”
with power supply
1 LED=2.5v
2 LEDs=5.01v
9 LEDs=22.74vLeave a comment:
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Re: “How to test LED screen?”
Use Vf is good idea.
I use my Fluke 77
1 LED=0.76v
2 LEDs=1.53v
3 LEDs=2.29v
4 LEDs=no reading
5 LEDs=no readingLeave a comment:
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Re: “How to test LED screen?”
Find one good and cheap, somehow look like @Alastair E's ideas
The variable high voltage power supply 0-300V
[url]http://www.eleccircuit.com/the-variable-high-voltage-power-supply-0-300v/[/url]
Special thank to Alastair E ........I can't believe...... .We make a big circle then come back to his idea......Would save us months of works......
I will built at weekend and come back.... %$%$#^%#^....Good...%$@#^.....smart guy....man.....
[Music] Sleepsong Secret Garden HD
[url]...Last edited by Peter Chiu; 04-23-2015, 11:29 AM.Leave a comment:
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