Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
oh! the schematics is "Using Multiple Phototransistors"--"circuit 1--parallel phototransistors",the later of this page!
And ,the light is laser beam,the only one phototransistor can recived light signal at same time.
It is indicated the light signal the positive signal of diode,but it is 4.41V...
i 've make a circuit according with this links **broken link removed**.
my schematic is
1.but i have not R6=3M on hand ,so empty it. It is prefer 3.8 volt at the output of OP07 pin 6,with the input signal changed,so, i don't know it is cause of the R6 missing?
2.If i settle c1, it is vibrate...
"Distortion? What voltages do you see at various points? Remember that the output of the ULN2003 must go high to turn off the LED.
Maybe you accidentally grounded pin 9 (diode common) of the ULN2003. That would turn on all the LEDs. "
the high voltage at the segment pin(eg,seg A, seg...
Hi,Thank you!
The question is about solved!I add resistors 10KΩ at the collector of 8550 to GND,and 1KΩ at the output pin of uln2003 to +12V,the signal shape is properly.
It is 4" size the seven segment LED ,and work under 12V.Is it have much capacitors? So if the resistors can sink some charge...
Hi!
Driven common anode seven segment led,+12V power,scanning display,6 meters RV cable(impedance unknown).it is not work properly,it is always display "8".The signal is properly at input pin of uln2003 and the base pin of 8550,but the signal is very distortion at the output pin of uln2003 and...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
