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.
sir i have design a time domain reflectometer .i m getting reflections on oscilloscope.time difference between transmitted and reflected pulses is 4 microsecond.how can i measure this time difference using PIC16F877A MCU.i need ur help.
regard:
student
hello keith!
for your concern...
can u tell me what thing will determine the minimum range of the laser range finder? u once mentioned something about it.
actually the TOF keeps on increasing after 50cm.. but before that it gets reversed... can u explain this phenomenon.?
can u please help me with this thing?? i am not sure about it..
- - - Updated - - -
Keith..
that bundle of black wire is to produce delay..
because the TDC chip has two stop channels and it needs 3.5ns b/w the two stop channels... so i am using the same stop pulse for two stop channels and...
keith do u mean that the rectangular part of the received pulse is just the overload recovery?? i am using the rising edge of the rectangular part to stop the timer.. i am not considering the negative going pulse at all!! :shock::oops:
well yes the yellow pulse is the transmitted pulse (acquired from the laser driver output just before the laser diode) and the green pulse is the received pulse (acquired after the second stage amplification) ...
and i require the rising edges for the operation of start stops timers of the...
well thanks for your reply keith... but unfortnately the circuit which you have shown me is showing only oscillations!! nothing else!! :-(
however the previous schematics which i posted are showing me the received pulse!!
now this circuit is giving me a good response.. i mean these pulses...
thanku keith for your concern...
well actually with the same setup ( except that i am using two supplies for LM6361 ) i am able to see the laser pulse.. but the fluctuations are still there..
i would appreciate if u can give me details about the schematics of the receiver you are talking...
i have already done this thing Keith... the signal is jitter free till the output of MOSFET driver (EL7104) for laser diode (SPL LL85).
then at the receiver end after the PIN photodiode (S1223) there is the 1st stage amplifier which do not introduce much of noise.. but after that the 2nd stage...
yeah FvM .. i mean that the time of flight is not constant for the same target...
on the oscilloscope.. if i see the transmitted pulse and the received pulse.. then the time delay b/w the 2 pulses is not constant but keeps on fluctuating...
and its the received pulse which shows fluctuation...
i am making a laser range finder.
the receiver i have made is showing a lot of fluctuations in the received pulse. (10-20 ns)
can anyone tell me a solution to it.
i am using two stage amplification..
in first stage:
transimpedance amplifier:
op amp: AD829
in 2nd stage:
voltage...
hi..
i am using MOSFET driver ic EL7104 for the pulsed laser SPL LL85.
the circuit is giving proper response on the breadboard and the laser is emitting pulses.
but now once i made the PCB of the same circuit. the driver ic is not giving any response.
i have used the oscilloscope to check the...
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.
