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Truthlover
Feb6-10, 10:20 AM
Hi everyone, I just want to know if anyone here have a schematics to build a frequency multiplier. All I have see for the moment is multiplier with a factor of 2. I'm searching a factor 78 frequency multiplier. Also if it exist in a chip i would like to konw it to.


Thanks

Bob S
Feb6-10, 11:44 AM
The first PLL / frequency multiplier chip (I think) was the NE565 chip in the early-mid 1970's. A block diagram of a NE565-based frequency multiplier is shown in
http://www.circuitstoday.com/wp-content/uploads/2009/09/NE-565-Frequency-Multiplier.jpg
In your case, the frequency divider is by 13 by 3 and last by 2. I put the divide by 2 last so that the NE565 gets a 50% duty cycle square wave. To see inside the NE565, see
http://www.alldatasheet.com/datasheet-pdf/pdf/118262/ETC/NE565N.html

Bob S

waht
Feb6-10, 11:47 AM
What is the frequency you are trying to multiply?

Truthlover
Feb6-10, 11:49 AM
What is the frequency you are trying to multiply?

it's variable from 1Hz to 20 Hz to get at the output 78Hz to 1560 Hz

Averagesupernova
Feb6-10, 12:48 PM
There are several ways to do this depending on how accurate you need it to be.

Truthlover
Feb6-10, 02:48 PM
I don't need a high accuracy. \pm 2 Hz at the output is good enough for me.

Truthlover
Feb8-10, 07:22 PM
he's there someone here

berkeman
Feb8-10, 07:35 PM
he's there someone here

What about Bob's suggestions in post #2?