# help me with this Circuit Design!

#### THEKID

Joined Jun 29, 2006
1
hello everyone, im quite newbie here and would like just to ask one question..

Design a circuit with the following criteria.

1. There must be at least 7 resistors used.

2. All resistors must be different values.

3. There are to be at least 2 parallel networks.

Voltage= 18 Current= 5mA

i just need help with this question, would love if you help out of this..

#### Dave

Joined Nov 17, 2003
6,970
To give you a starter, the overall resistance of the network is 3600 Ohms. I would recommend having 3 parallel networks (6 resistors), with resistance Rp1, Rp2 and Rp3. Then you can place these three parallel networks in series with the 7th resistor, Rs.

The total resistance Rtot = 3600 Ohms:

Rtot = Rp1 + Rp2 + Rp3 + Rs

Where Rp = (R1*R2)/(R1+R2)

NB: each parallel network has two resistors.

Since there are no restrictions on the values of resistors you can use, just use the above Maths to get the values you need. You don't need any other equations than the ones I have written above.

If you have any further questions, don't hesitate to post back. Other than that you can post up your working and I'm sure someone will check it is correct.

Dave