DC source voltage amplification

[Boosan]

Hai,
I have a 3 volt DC supply output from a RF Sensor,
now i have to connect it as input to an 12v DC motor..
I need to convert this 3V to 12V..
How could i do that..?? But with a simple simpler or by the most simplest way??

 

[kripacharya]

use an opamp with gain = x4 followed by a totem pole NPN/ PNP bjt setup and feedback to the opamp from the emitter junctions.
Connect the emitter junction to your motor also.

That will work for your requirement as stated

 

[jiripolivka]

Hai,
I have a 3 volt DC supply output from a RF Sensor,
now i have to connect it as input to an 12v DC motor..
I need to convert this 3V to 12V..
How could i do that..?? But with a simple simpler or by the most simplest way??

If I understand what you wrote, your RF sensor has 3 V DC output and you need to use it to drive a 12 V DC motor.
This is not done by amplifiers but by a relay controlled by 3 V DC which will close or open contacts in the motor circuit powered from a separate 12 V DC power supply.

You do not give details about the RF sensor 3 V DC output POWER. MOst sensors generate a low power which possibly can drive the relay coil. If not, then I would use a TTL or CMOS logic gate which can deliver ~10-50 mA for relay coil. You can also use a 555 timer or an opamp for it.

For a better advice, more information is needed about the sensor 3 V DC output, and about the DC ,motor to be driven.