Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

ECG Circuit - need help identifying component

Status
Not open for further replies.
B

balintrigo

Newbie level 4
Joined
Sep 5, 2011
Messages
5
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,315
Hello

I am trying to acquire the components necessary to build this circuit (see attachment) View attachment EKG Circuit 8.pdf. My problem is that there is no partnumber for the switches A, B, C, D. What kind of switch do these represent? Also, there are several resistors with no value written on them - what resistance is needed there?

Thank you!
 

The switches are ICs and referred to as "analog switchs". Where did you get the PDF? can you post the URL?

Ken
 

    V

    Points: 2
    Helpful Answer Positive Rating
It came from here: which is on this site:

Keith.
 

    V

    Points: 2
    Helpful Answer Positive Rating
Thank you, that really helps :) I also noticed there is a comment saying Wilson 'Terminal Adjustment resistors: R arm = 2.6 Left leg, L arm = 2.6 L leg' I am still not sure how to figure out the value of the Left Leg resistor. There are also two resistors connecting to 2 and 15 of the INA103 with no value, any hints for those?

Thanks
 

The resistors are all between low output impedance buffer amps and a high input impedance instrumentation amp. Since they are just used for summing, you can pick values in the 10K range that will give the appropriate ratios. The ratios are more important than the specific values. I would try 10K for LL and 27K for LA and RA for starters. You can figure out 1% resistors that give a closer ratio.

Ken
 
Thanks for your help Ken! For the switches, would I be alright if I used a low on-resistance switch such as the ADG881? (ADG881 | 1)
 

Could someone recommend a good e-shop where I could order these components reasonably priced? Thx
 

Farnell sell the ADG811 (you say ADG881 above but there is no such device).

Keith.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top