i want to produce negative volts from 5V?

• Jun 7, 2005

• #1

X

xxtigerxx

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i want to produce -5Volts and i have only ground and 5Volts..

THX.........

 

• Jun 7, 2005

• #2

I

instruite

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What is the load where you want to connect -5V?


Instruite
===============
Ideas that work,
Concepts that sell.
===============

 

• Jun 7, 2005

• #3

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IanP

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For small currents (<300mA) you can use simple circuit based on 555 timer:
https://www.aaroncake.net/circuits/vinvertr.htm
Regards,
IanP

 

• Jun 7, 2005

• #4

X

xxtigerxx

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the load is 20mA...

 

• Jun 7, 2005

• #5

snoopy

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You can use also ICL7660 voltage inverter.

**broken link removed**

Bojan

 

• Jun 7, 2005

• #6

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vdaniel

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If -4.1V is enough, then I highly recommend to use the Linear Techolology's
LTC1550L, because it makes practically no noise.

Varuzhan

 

• Jun 8, 2005

• #7

R

rhesusmonkeyboy

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You need an inverting buck-boost, which is an "easy" switched-mode power supply circuit, in its simplest form.

It'd require a pmos, gate drive, diode, inductor, and cap.

I don't know how to link things, I apologize, but if you search for those terms you'll no doubt find a schematic. ^-^

 

• Jun 8, 2005

• #8

djalli

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A simple ancient 741 opamp can do that

 

• Dec 26, 2005

• #9

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johnsmith101

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You can use an inverting buck-boost switching regulator or an inverting charge pump regulator depending on your load requirements.

 

• Dec 26, 2005

• #10

the_risk_master

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Or... You may want to connect the 5v to the OpAmp inveting amplifier

 

• Dec 27, 2005

• #11

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Nimer

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hi
the use of inverting opamp with unity gain is possible ,choose aone that uses single vcc supply of 5 volts so that you dont use extra sources


best regards

 

• Dec 27, 2005

• #12

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johnsmith101

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Sorry, you cannot use an opamp for this since the only supply available is 5V. You definitely have to use some type of switching converter whether it is inductor or capacitor based.

 

• Jan 3, 2006

• #13

H

huji

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Connect GND between 2 DC 5V supply and u will get 5V & -5V.