design and constyruction of a digital multimeter

[phebe32]

Can anyone help me with concrrete detail on how to design a digital multimeter . I want to know how , the materials needed , circuit diagrams etc

 

[Sangoma]

It would cost you many times more than to buy one!

What do you want it to do?

What input impedance?

How many digits and what accuracy?

 

[Dragon Tamer]

There are actually ICs you can buy with all the circuitry needed and are capable of driving an LCD or LED display.

Here is one such example for an LCD display.
ICL7129

Here is the one for an LED display.
MAX1447/ MAX1498

The only thing you would need to add is an external scaling circuit for higher voltages. Sangoma does have a point though, unless you want to integrate it with a larger circuit it would be much cheaper and easier just to buy one.