Low Voltage regulator

[mesamune80]

Hi all,i would like to build a voltage step up for my force sensor .As i know the output from the sensor is quite small about (few mV) only.so inorder for me to detect it i need to boost up the voltage to a significant value (few V).Is there any way for me to achieve this?
Thanks All.

 

[kchriste]

You can use a low noise, low offset, op-amp to amplify the voltage signal.

 

[mesamune80]

Thanks for your info but after browsing through the web i still not sure which one to use. >_< i am currently using LM124 to amplify the output signal from the sensor,but i am not sure whether it is suitable or not,this Op-Amp can give me a ~100+ gain.
But afer the amplification i need to do a window comparator to control a motor.(TTL logic 5.0V)
For comparator i used LM 119 for the job,so is there any good combination to subsitute these 2 IC? or any better way to do the job?
Done mind to share out your idea ya?
Thanks ^_^

 

[on1aag]

Hi Mesamune80,

A replacement for both, op amp and integrator could be a LM392.

https://www.electro-tech-online.com/custompdfs/2007/04/LM392.pdf

A better choice would be a dual precision rail-to-rail op amp like
the OPA2350. ( And use the second op amp as a comparator. )

https://www.electro-tech-online.com/custompdfs/2007/04/sbos099c.pdf

There are a lot of other suitable candidates for that task, search
for a dual precision rail-to-rail op amp.

on1aag.

 

[mesamune80]

Dear All,

I had used the previous ICs to do the job but,i am not sure for the new part that recommended like OPA350,LM392 i mean the circuit design for the part can i just follow what i had designed and replace the IC instead? and for the window comparator i just replace the old one (LM119) to LM392?
**broken link removed**
this is the circuit that i used now.
Thanks

 

[on1aag]

Hi Mesamune80,

You should have added the schematic in your first post.
The first part of your circuit is actually an instrumentation
amplifier, the problem is that all resistors should be matched
to 0,1 % and these resistors cost about € 1 each . . . .
I think you should replace the first part of your circuit with
a real instrumentation amplifier and only one resistor. ( For
the gain setting.)

https://www.electro-tech-online.com/custompdfs/2007/04/AD623.pdf

For the second part I would suggest a dual comparator like
the LM393, nothing special about that.

**broken link removed**

on1aag.

 

[mesamune80]

Thanks on1aag for the information,after glance through the data sheet i feel the device that you recommended is more suitable for my project i'll try to seach for the device.^_^

 

[mesamune80]

Ya i forgot 1 thing here,as the window comparator need 2 input source as upper and lower limit voltage range ,any better way for me to do a adjustable volage regulator?
From 0V as input voltage,what i currently use now is as below:

**broken link removed**

but i think this is not very suit my design,any good ideas?
Thanks.