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Not pulses. It oscilates like some kind of sinuse (it's not sinuse) with frequency of 1Hz. But I am doing measurements with AC disconnected, because my oscilloscope is grounded. I don't know if it's legit, but electrolytic capacitors still hold charge for very long time.
Which diodes exactly? I have a service manual, but I don't know if I can post it here. I can tell you the name of the model and you can google service manual. It's quite accessible: PHILIPS MCM3150.
Thank you.
Hm, I replaced IC3 and Q16 and I still don't get any output on gate pin of IC3. I get some sort of square waveform on VDD pin (5V 200ms inpuls every second). I tryed to put 3V to FB pin and still no output on gate pin. Do you think that new replaced IC3 died? What could be the cause of it? I do...
Datasheet: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwipo-So8djhAhUSsKQKHSnDBTsQFjAAegQIAxAC&url=http%3A%2F%2Fwww.ebvnews.ru%2Fdoc%2FFAN6754.pdf&usg=AOvVaw3NTsD9ba6NjlmZWAj6XNEG
I am using oscilloscope and voltmeter. How can I connect oscilloscope for...
So at first, IC3 is powered from high voltage of rectifier bridge for start-up, then it starts to oscillate and voltage is induced in auxiliary winding. Then it's supplied from there. Is it possible, that IC3 is somehow starting and stopping, because I can measure some variating DC voltage on...
Hello guys,
I am looking at schematic of a SMPS for some audio system and I can't figure out, how the heck does that high frequency transformer work... I don't understand the winding for supplying IC3 (PWM controller). Is this primary or secondary winding and how can voltage be induced on it? I...
Hello guys,
I don't know if I am in the right forum, but please move topic if that is so.
I would like to ask you guys for ideas and suggestions. What would be the best industrial solution to implement local database parallel with PLC system? To be more clear: I need to implement some simple...
Exactly how would resistors in each string equalize currents through leds? I am talking about configuration with constant current power supply and multiple parallel strings of series leds with series resistors?
Oh, and btw, how about this circuit for equalization of current?
I guess, I'll really have to omit the protection and maybe just use some current mirror to equalize currents. I hope that non of the leds dies, or at least just one string.
I think I came to a solution. I will use current mirror with aditional bypass transistor, which can whitstand 6A of current in case, no string is connected, so all the current passes throuhgh this transistor. I draw a circuit in LTspice and simulated it and it works. Please, ignore part values...
I have a constant current supply ready for this led matrix.
If one led fails, the current doesn't flow through this string. So current has to flow through remaining strings, because I have constant current power supply. But I want to limit this current, so excess of current would flow through...
Klaus, i am afraid, that these Chinese leds won't stand any temperature drifts and over-currents. So, I would like to make some kind "bullet-proof" design, analog circuit preferred. Could 4 transistor current mirror be used in someway here, to balance currents and also protect leds from over...
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