Heart rate meter

[zesla]

Hello guys,

I have several questions regarding the bellow heart rate meter circuit:

Fast heart rate meter using CD4518 CD4046 CD4511 - Free Electronic projects & 8085 projects

Here are my questions.
1: is it a practical workable circuit? The provided info about it are very limited!
2: what is the functioning of the 4046 PLL there in the circuit?
3: Where are those D1 till D7 elements? and where are the sensors in the circuit?

Thanks in advance.

 

[zesla]

Oh I forgot to ask, I want to know how long I have to keep my finger in front of the sensor for this circuit or such circuits? just one minute or less?

Thanks like always.

 

[audioguru]

The CD4046 and CD4518 multiply the heart rate frequency so the heart rate can be counted in 1 second.
You should find the original project instead of this poorly translated copy that is missing things like the light or IR beam that shines through your finger.

Look in Google for the HEMON (HEart MONitor). Instead of using these old Cmos ICs it uses a microcontroller to do the same thing.

 

[zesla]

thanks,
Can I cause A led to be blinked by 4046 and 4518 by the circuitry of above? (remove the other IC's and the related componenets)

 

[audioguru]

You don't need the CD4046 and the CD4518 to blink an LED. The analog heartbeat signal can drive a transitor that blinks an LED.

 

[zesla]

Audioguru, I just want a circuit out of 4046 to enlighten/ or cause a led flashing so that I could test the 4046 itself.
Make sense?

 

[audioguru]

I don't know what you are talking about. An LED will not show if the CD4046 is working properly or not.

The CD4046 is a high frequency voltage-controlled oscillator and the CD4518 counter divides its frequency down to be close to the heartbeat frequency. The phase detector in the CD4046 syncs the two low frequencies.

It is complicated to test a CD4046 because it has many functions and circuits inside. I don't think this circuit works because it is missing a few things.

 

[zesla]

I just want to add a 555 Astable and then use the 4046 (and4518 if needed) to see if the 4046 is ok or not.

 

[audioguru]

Adding an astable oscillator will test only one function (one phase detector) of the many functions in a CD4046.

I have used thousands of ICs. I never tested any of them (but I tested every product I made with them), they all worked perfectly and none have ever failed.
Why are you worrying about if one CD4046 is OK or not? Is it made by a Chinese company?