convert +/- 10v sin cos to 3-digit LED (representing 360 degrees)

[ayeweed98]

I am looking for input as to how to put together a circuit that will convert an analog voltage (+/- 10v) source (sin & cosine) into a usable digital voltage that will drive a 3-digit LED module (LB-203BL or equivilant size). This input signal represents an analog input from a course setting on a compass type instrument. Thus, the corresponding output will be limited to a 0-360 reading (representing degrees of the compass)

 

[nbucska]

I suggest using a microcomputer with built-in at least two chanel A/D converter.

<nbucska@pcperipherals.com>

 

[ayeweed98]

the circuit has to fit inside the instrument case

 

[nbucska]

How much volume ? What kind of voltages do U have ?
Any accuracy or speed spec's ? <nbucska@pcperipherals.com>

 

[ayeweed98]

also available are +28v, +/- 15v, +/-10 volts (on sin and cosine from course knob).

There is now volume reqment. so you understand, i'm talking about replacing an existing mechanical course counter, with an LED. the input for the display (3-digit LED) has to be tied to this analog sin cos signal, and give a 0-360 degree display, based on this signal.

 

[nbucska]

You haven't answered some questions.

Using e.g. a PIC18C242 in 28 pin SOIC package you could
easily build it on a 2&quot;x1&quot; PC board ( less than .2&quot; high)
-- not including the LED display. The PIC is around $8.-
in low quantity. It has 4 channel 10 bit ADC in it and 8Kx14 bit program flash memory.

The PC board will be more expensive ( multilayer) unless
you have large quantity -- in which case further search
for cheaper alternatives is justified.



<nbucska@pcperipherals.com>

 

[melone]

WHAT INSTRUMENT CASE?????

 

[ayeweed98]

again, this is to modify a simulated flight instrument. i need to replace a hardware, 3-digit tape counter with a 3-digit LED that will represent 0-360 degrees, based on the position of the course knob. this course knob provides a +/-10v sin/cos signal that will be used to generate the 0-360 degree LED display. i hope this answers the &quot;what i'm building&quot; questions.

the circuitry has to fit inside the confines of the instrument case. The counter that is being removed is about 1&quot;x3/4&quot;x3&quot;(deep), so this is how much room i have to put the new circuit. the LED modules i am intending on using are LB-203BL or equivilant size.

i understand that some sort of A/D device will be required, along with some logic that will have to generate each of the the 360 degrees for the LED segments. It is the specifics of this that i am interested in. i am a maintenance technician, not an engineer.

Thanks to nbucska for the interest. could you go further with that thought? i could certainly use any diagram info you could provide.

 

[melone]

ayeweed98 , you never said what this was for until your last post. Can you run a cable from the LED module? Otherwise, you are going to be forced into spending some money to get things to fit and work in that volume of space.

How to you plan on supplying the power? What type of power do you have available? How much noise is generate in the surrounding instrument cluster? Will you have to put this in it's own enclosure? If so, what size? Are there any onsite experts at your facility? etc...

We will help you, but we need a little more to go on.

 

[ayeweed98]

thanks so much for the interest.

let me see if i can answer all the questions, and sorry for the previous lack of clarity.

a cable COULD be run to the LED module, and the newly created electronics module could be mounted elsewhere, but we would like to put the whole package in the instrument case. this is NOT a limitation, though. the space available is about 1&quot;x1&quot;x3&quot;deep.

as long as it is not extravagant (thousands), money is not a huge issue just yet.

power sources available are +5v, +28v, +/-10v, +/-15v and can be tapped into with little problem.

i'm not aware of noise problems, and have no idea what noise limitations would have to be addressed.

there are no circuit design experts on site, but we are all fairly clever and adept technicians. if it can be designed, we can build it here. thus the need for the help.

if you e-mail me personally, i can send you photos of the instrument we are working on, what we are replacing (and WHY), and the size limitations we are talking about. a picture is worth a 1000 words, eh?

again THANKS for the interest !!!

 

[nbucska]

Do you need to build only one or is this for production?
Your E-mal and FAX# ?
<nbucska@pcperipherals.com>

 

[ayeweed98]

there will be 4 produced if it is to be mounted outside the instrument. if it can be placed internally, we will need 6 of them.

e-mail to spaceboy1960@aol.com