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Check my frequency meter design

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pic-novato

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Hi

I built this frecuencimeter, but the input stage is very simple, i can`t adjust for diferent values of Frecuency, have somebody a better diagram.

Thanks in advance
 

Borber

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frecuencimeter pic 16f84a

This input stage is enabling you to measure frequencies up to about 50MHz. Sensitivity is about 0.1Vpp. What is your problem?
 

pic-novato

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test prescaler circuit

Hi Borber:

I try to adjust the x point to 5 v, but can't do it, only 4.2 v. I change for 1000 ohms preset.

I use this circuit to measure square signal, i built a circuit to give me signals from 1 Hz to 20 Mhz. But when i adjust the preset to read low frecuency (> 1 KHz) i can't read hi frecuency, and when i adjust for read hi frecuency (< 5 MHz) can't read low frecuency.

I can measure square signal with this input stage?

And i looking for a stage to 1 GHz using a prescaler.

Thanks
 

Borber

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frecuencimeter projects

Change 470pF capacitor to 100pF.
Input stage up to 1GHz has no sense.
 

pic-novato

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frecuencimeter pic

Thanks Borber, i will change the capacitor and test it.

Why you think has no sense put a prescaler in the entrance?

Please take a look this circuits. I know its a 64 or 256 prescaler, but i will modify the program.
 

Borber

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frecuenciometer

Sory, I missed the word prescaller. Of cause it makes a sense to use it.
 

hermin

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diagram frecuencimeter

I wanna ask something, if you simulate this circuit on electronic workbench, would a frequency sweep be a useful tool in checking the input stage of the device?
 

anthony123

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frekuenzmeter

Hi.. i'm writing from Venezuela.:! I've a little ask.. ¿Anybody of you has make a good frecuency meter that can measure low frecuencys (1-30000 Hz) until some one high like 5 Mhz?
 

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