subodhthok

Pls Somebody why is Q4 & R7 used?

I admit I was wrong... :-[. But I'm a newbie...& sometimes confused :-*. But I'm very much keen in electronics....and hope that one day I understand all. Please tell me what are the functions of R7 & Power Transistor Q4.

Where the end pins of RV1 should be connected?

I dont think that's right....

Pls Reply Soon!

I building this circuit on a multi-purpose board. Kinda confused about RV1. The middle pin of RV1 is connected to R1. Other 2 pins to which pins of U2??? I think one is connected to pin 6 (o/p of U2) but the other????

Can somebody give me the principle and working of the circuit mentioning the function of each and every component. I'm a POOR SOUL. I'll be INDEBTED!

I'm Kinda confused :-\...... though this seems to be a good project! Can somebody gimme the Block diagram! Thnx in advance!

And I'm needing a bit urgently............ ;D

So please send me a cct diagram to fit Display. I'll be indebted. Can the cck be like.... O/P from cct->Sample cct->Counter->Display Help me with a cct diagram that's most likely to work. I'll try it! Thnx in advance

:D Hi All.... This circuit works perfectly using LM386 at U5. Now will it possible to put a display (LCD/LED) at the output where it can count the heartbeat?