Re: attempt to clone LED TV Backlight Tester
What about just buying a cheap buck/boost converter off ebay with an amp/volt display.
You could get a voltage reading feeding the LEDs from the tv board, and feed that voltage to it.
attempt to clone LED TV Backlight Tester
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Re: attempt to clone LED TV Backlight Tester
https://www.youtube.com/watch?v=DHj-UnG-qQU , is it usefull ?Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
Well, then what is the best leds strip tester we can build that is the most similar to gj2c? In my country we use 220v acLeave a comment:
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Re: attempt to clone LED TV Backlight Tester
The led tester has just turned up 12 days delivery to the uk not bad at all i will strip the tester down shortly and take some pictures.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
"it is exactly the same principle as the light bulb in series to test power supply or any circuit that has a short." Really?Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
I know what you are saying but when running this test I have 0.01A that is passing in the circuit is harmless, it is exactly the same principle as the light bulb in series to test power supply or any circuit that has a short.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
We are talking the reverse Voltage breakdown of the LED or any diode.
I know your setup, no need for pictures. Just look up what reverse breakdown Voltage of the diode is.
What do you think what the reverse Voltage is aplied across the LED when it is in reverse bias during the half cycle of the applied AC?
There is reason why minimum diode break down Voltage is chosen to be used in the circuits.Last edited by budm; 04-01-2017, 12:17 AM.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
I can test only one led or more led's there is no problem. I don't need to see the polarity cause I'm applying AC voltage and this voltage will be rectified directly by the same leds that I'm testing. So I'm having half wave in the led thats why is irrelevant the polarity. The only thing is that the led will blin will blink 50times a sec here I live is 230v 50Hz but I can barely see this. I will post some pics if you want.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
That is why I said it is also dangerous (to human and device) and good LED can be damaged, at least put 1n4007 in series and have to test with correct polarity. You can be lucky for so long.
https://www.digikey.com/en/articles/...ial-protectionLeave a comment:
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Re: attempt to clone LED TV Backlight Tester
So I will tell how I test my LED strip from TV all strip at once without any tester. I have a old outlet cable that I took from a radio and I have cut and put 10kohm/2w resistor in series then I make one probe, in the other able i only have put one probe.
When I need to test LED from a TV I put the cable in a 230V outlet and test directly the strip not even have bother in see the plus and minus..
Here you have the most cheap, free of electronic waste, and reliable I use this for more then 4 years nowLeave a comment:
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Re: attempt to clone LED TV Backlight Tester
Yep, cheap, works, and dangerous. Max current worst case is 23mA.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
So I will tell how I test my LED strip from TV all strip at once without any tester. I have a old outlet cable that I took from a radio and I have cut and put 10kohm/2w resistor in series then I make one probe, in the other able i only have put one probe.
When I need to test LED from a TV I put the cable in a 230V outlet and test directly the strip not even have bother in see the plus and minus..
Here you have the most cheap, free of electronic waste, and reliable I use this for more then 4 years now
Have you tried using back to back transformers for isolation?Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
So I will tell how I test my LED strip from TV all strip at once without any tester. I have a old outlet cable that I took from a radio and I have cut and put 10kohm/2w resistor in series then I make one probe, in the other able i only have put one probe.
When I need to test LED from a TV I put the cable in a 230V outlet and test directly the strip not even have bother in see the plus and minus..
Here you have the most cheap, free of electronic waste, and reliable I use this for more then 4 years nowLeave a comment:
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Re: attempt to clone LED TV Backlight Tester
I have traced some of the circuitry, it makes better sense now.
With the test leads open, the Source of Q1 rises to the point where the G-S drops to threshold voltage of about 2.5v. Q1's channel resistance will be very high.
When the leads are connected to a load, very little current first flows through Q1, the current increases as C8 charges. Q1 eventually ends up with about 3v drop across it.
The current limiting is done by an unidentified SMPS IC that I have represented by Q2.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
yes paypal charged me £1.00 i think but still a cheap tester at that price.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
Any tricks in the payment because all the prices are too good to be true(some of items are $0.01)? Why dont they accept VISA?
Western Union (No Bank Fee) , but it is bank to bank transfers maybe charge $50
PayPal (PayPal Fee 5%) * Shippment address must match with PayPal register address
MoneyGram (No Bank Fee) ???
HSBC Bank (Bank Fee $25.00)
Alipay.com (Need to contact us) ???
https://www.hklrf.com/Payment_1.html
I use PAYPAL, so LRF will charge 5% fee and added that to the price?
It also show accept credit card on the right side of the page.
https://www.hklrf.com/0-300V-Smart-F...pair_1948.htmlLast edited by budm; 03-31-2017, 12:50 PM.Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
How about Payment? They doesnt accept VISA?
Western Union (No Bank Fee) , but it is bank to bank transfers maybe charge $50
PayPal (PayPal Fee 5%) * Shippment address must match with PayPal register address
MoneyGram (No Bank Fee) ???
HSBC Bank (Bank Fee $25.00)
Alipay.com (Need to contact us) ???Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
Any tricks in the payment because all the prices are too good to be true(some of items are $0.01)? Why dont they accept VISA?
Western Union (No Bank Fee) , but it is bank to bank transfers maybe charge $50
PayPal (PayPal Fee 5%) * Shippment address must match with PayPal register address
MoneyGram (No Bank Fee) ???
HSBC Bank (Bank Fee $25.00)
Alipay.com (Need to contact us) ???Last edited by capwizard; 03-31-2017, 11:29 AM.Leave a comment:
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