basic range sensor (URGENT) by using Opamps not timers

[elvinme]

i am required to design a range sensor by using opamps, any kind of capacitors,resistors,LEDs . Timers are not allowed to be used. Also only DC voltage sorce allowed it should not be more than 3 DC sorce. th basic requirement are that:
design a circuit that measures 0-60cm diistance and by the help of 4 LEDs visualize it.
0-20cm 1 LED is on. 20-40 2 LEDs an so on.
TSOP1138(TK 19) allowed to use of course

 

[blueroomelectronics]

Sounds interesting. Keep us posted.

 

[#12]

You could look at the bottom of this page and see what almula learned when he posted the same homework assignment.

 

[elvinme]

timers are used in that project. but we are not allowed to use them.olny opamp and TK19 should be used.

 

[blueroomelectronics]

So far so good.

 

[atferrari]

Yes, I run across almula in the chat room seeking for help. But he seemed quite unable to explain the problem more or less precisely.

 

[blueroomelectronics]

Ahh, so far all his posts are statements not questions.