Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
Solved

# XTAL

Posted on 2002-06-10
Medium Priority
223 Views
HI
Can I change a crystal 1 MHZ with RC circuit if there any alternative circuit please, tell me so as to make my device work. If you have any documents about oscillator or links tell me about.
NOTE: I DON'T HAVE THIS CRYSTAL.
Regard
0
[X]
###### Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

• Help others & share knowledge
• Earn cash & points
• 4
• 3
• 2

LVL 7

Expert Comment

ID: 7067607
No ... ( rc circuit).
1 Mhz crystal is the best way if you want a "good" (exact) clock generator.
You can find clock generator IC (Cypress for example) but you need also a Xtal ...
0

LVL 7

Expert Comment

ID: 7067612
0

LVL 32

Expert Comment

ID: 7067868
An RC network is NOT a good replacement for a crystal.  It's possible with an LC circuit but the results will be less than desirable.

Why do you want to do this?  1MHz crystals are common, easy to come by, and quite inexpensive.  You can probably find them free or close to it at a junk shop or HAMFest.

Anyway, most cyrstals are PARALLEL RESONANT and so a parallel LC circuit will give similar characteristics BUT at a MUCH MUCH lower "Q".  "Q" is the "peakiness" of the circuit and crystals are used because their "Q" is VERY high.  That's what makes them so good to use in an oscillator, since they peak so highly they run only at the resonant freq.  The problem with LC substitutes is stability, they need to be manually tuned to begin with and they drift due to temperature, humidity, age, etc.  Be prepared to go from a 1MHz that runs at +/- 1% to +/- 50% or more with an LC.

The freq. for a parallel LC circuit is: F = (2*PI)/SQRT(LC)

Now the trick is finding an available L and C (remember these are manufactured in standard values) that will run at about 1MHz.
0

Author Comment

ID: 7069648
Thanks ,frache & jhance.
I want to input a voice into computer by codec and some ACC circuits that run at  about 1MHZ.
Please , jhance give me more details and internet topics.
Regaard.
0

Author Comment

ID: 7069701
Thanks ,frache & jhance.
I want to input a voice into computer by codec and some ACC circuits that run at  about 1MHZ.
Please , jhance give me more details and internet topics.
Regaard.
0

LVL 32

Expert Comment

ID: 7069803
I don't understand your problem.  You're designing and building a CODEC circuit (which DEPENDS on a rock-solid timebase for proper operation) but you want to substitute for a inexpensive crystal???

0

Author Comment

ID: 7070773
OK ..I'am in far country in Africa ,and I can not bring this item to my country before one month and I want to complete my design in this week.
thanks
0

LVL 7

Expert Comment

ID: 7072210
There is perhaps a way to find a crystal in your country : try to find an old computer ...
0

LVL 7

Accepted Solution

frache earned 900 total points
ID: 7072219
Here you can find a lot of information about oscillators :

But for your design, the best way is to find a crystal ...
0

## Featured Post

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Stuck in voice control mode on your Amazon Firestick?  Here is how to turn it off!!!
New style of hardware planning for Microsoft Exchange server.
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infrasâ€¦
In response to a need for security and privacy, and to continue fostering an environment members can turn to for support, solutions, and education, Experts Exchange has created anonymous question capabilities. This new feature is available to our Prâ€¦
###### Suggested Courses
Course of the Month4 days, 20 hours left to enroll