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so, i simply connected a LED (forward voltage of 3.3v) with a series resistor (85 ohm), that should give 20mA of current to the LED.
then , connected the frequency generator to the series circuit, the LED worked pretty good at about 900kHz .. but when i kept to 10Mhz or more than 3-4 Mhz...
If i sending 9600bps ..how to approximate what frequency it is ?
lets say if i am giving 10kHz square wave....--> what Bps it is ?for 10khz frequency how many bits i can send per second at max?
on the other thread i saw 1Hz is 2bits... so 10kHz is 20kbps ???
I have seen a lot of calculations where they take GAIN as 10 or 20 instead of the original value in the datasheet.For example 2n2222 transistor
VCC = 5 ,Led(Vf = 3v).
For Ic = 20mA,Rc = [VCC-VF(LED)-VCE(SAT)]/Ic = [5-3-0.25]/20mA = 87 ohms.
Ib=Ic/Gain = 20mA/110 = 0.18mA
Rb = [Vcc-Vbe]/Ib =...
i designed a basic circuit as in the picture.When i given the voltage from voltage regulator.The measured current through LED is same as the simulation = 12.7mA. but when i connected to the Frequency generator(10kHz with DC OFFSET of 5V),
the current through the LED is double the value ??why is...
i want to plot a 3 dimensional graph.
x-axis 1 2 3 4 5
y-axis 10cm 20cm 30cm 40cm 50cm
z-axis 0.5 0.6 0.7 0.8 1 3
these are my values,i cannot able to plot these in 3D .. it was easy with x and y but i am not able to place z-axis..is htere any equation i should place ?
is there any software that decodes a picture into codes (html,c,c++ ) and encodes it back ?
operation should be...
1)upload a picture in the terminal
2)get the code language
3)paste the code language again
4)extract the picture from the coding.
I have a chip (SN75451B).I am trying to understand the function of it so that i can built a circuit which shows the function of it.how to test it?i mean i want to give a Square wave to the input and i want to see the output signal.what are the parameters i should consider...
As you can see.I built a circuit like above.I replaced 3.3Vdc instead of White LED(cant find them in my simulation software).The current for each LED suppose to get 11mA.but in practical board it is showing 4mA.Need to know what went wrong ?
this the circuit i built (transmitter and receiver)for my project,As you can see i kept 1 white LED.Instead of the voltage at R1,i kept frequency generator to give square wave.
**broken link removed**
the above picture is the waveform from the lm339 comparator when i used only 1 LED with the...
my main object is ..i have 10LEDs i want equal current for all leds with the transistor 2N4401.i came up with this circuit design but not sure which one is a proper way.
Led forward voltage = 1.4(approx in pspice),
Led maximum current for each = 20ma
i am thinking the base...
How different are the USB and RS-232 ?? I know USB D+/D- works on a twisted pair and the speed is really different.I saw a lot of USB-RS232 converters(UM-232R)but i didnt find any converter in reverse.Why is that ,cant we convert the rs-232 data to USB ?
I got a problem given in my class ,trying to figure out the problem.
1. Design a two stage transimpedance amplifier using the picture
Since its transimpedance ( current to voltage conversion).So i have to design two transimpedance amps...
I read a lot about USB functions but i cannot find proper explanation about how Data is exchanged.For example if i connect a device like my iphone(or any other USB devices) to my computer ,how the computer recognises and how the D+ /D- in usb pins work to transfer the data ?
Thank you in...
I am testing UM232r (USB - Seriral UART) .. i have connected it to my computer (connected Pin 1(TX) to Pin 5(RX) for um232r) .When using the hyper-terminal , i am not able to get the characters i typed .. (used usb type a - type b cable to connect UM232r to computer usb port)
how to make it...