Help!!!!

[noskcaj]

Is it possible to step up an output of 2.8mV to a input of 3V? Please help. 10q

 

[Hero999]

Use a potential divider.

What are you trying to do?

It's possible you're doing it the wrong way.

 

[Nigel Goodwin]

Is it possible to step up an output of 2.8mV to a input of 3V? Please help. 10q

Yes, use an amplifier - an opamp would probably be easiest. Exact details depends on your exact requirement (which is much too vague).

 

[Hero999]

You're right, he wants an amplifier not an attenuator.

The language used is confusing, an output of 2.2mV and an input of 3V, implies an attenuator but the word step-up implies an amplifier.

Fixed:

Is it possible to build a circuit with an input of 2.8mV and an output of 3V?

Yes it is, you need an amplifier with a gain of 1071.

Does this output need to be linear?

Can it be 3V if the input's 2.8mV and 0V of it's less than 2.8mV?

If so you need a comparator, with the reference at 0V and a very small amount of hysteresis to remove th noise.

 

[audioguru]

He doesn't say if the signal is AC or DC.
If it is AC, he doesn't say the frequency range. It could be microwaves he needs to amplify.

 

[noskcaj]

Hi all,
Thank for the infor.

I intend to use the PC parallel port to control 4 output devices. I wonder is it possible to be done. I had information is that I could use a 3V relay to control the devices. But the problem is that the Voltage that is coming out from the parrallel port is like ard 3mV but how am I able to drive a 3V relay to let the relay works.

Hope I did made myself clear this time round.

 

[Nigel Goodwin]

Hi all,
Thank for the infor.

I intend to use the PC parallel port to control 4 output devices. I wonder is it possible to be done. I had information is that I could use a 3V relay to control the devices. But the problem is that the Voltage that is coming out from the parrallel port is like ard 3mV but how am I able to drive a 3V relay to let the relay works.

Hope I did made myself clear this time round.

The voltage out of the port is TTL levels, if it's only 3mV then the pin is set LOW and not HIGH.

 

[mkh]

The voltage out of the port is TTL levels, if it's only 3mV then the pin is set LOW and not HIGH.

i agree totally