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DIY Single to Dual Power Supply from 5V – 15V, with Virtual Ground

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by

Andrew
in ,

DIY Single Rail to Double Rail with Virtual Ground / Rail Splitter / Voltage Divider

Just released a video on how to create a small dual power supply based on a single power supply of between 5V an 15V.

Schematic update 2028.03.03.

NOTE: The pinout in the schematic does NOT represent the ฮผA741C pinout.

The video shows the schematic, a simulation in KiCad based on SPICE, and the final real working unit. Also a few measurements on the final unit to show how well it works: The “0V” output, alias middle or divided voltage, is less than 1/100 volt off from the middle between input ground and the input supply voltage.

What ever voltage input between 5V and 15V (when using ฮผA741C opamp), is transformed into a double rail +/- half the voltage, with an current output of up to at least 85 mA.

It is based on one OpAmp (ฮผA741C) and two transistors (2N3904+2N3906) with some resistors. Other OpAmps and transistors could be used too, though it might maybe need a change in resistors here and there.

If you used another OpAmp than the ฮผA741C, you could potentially reach a higher input voltage. The 2N3904 can already handle up to 40V (Collector โˆ’Emitter Voltage).

Video introduction

The introduction in the video presents two web pages and runs quickly over what they write on virtual ground and voltage divider. The two pages show various other simple suggestions for circuits. All depends on your needs, what’s best. If you want details in general on the topic, take a look at those pages.

The links for the two web pages

“Creating a Virtual Power Supply Ground” from forum.allaboutcircuits.com
https://forum.allaboutcircuits.com/threadsโ€ฆ

“Virtual Ground Circuits” from tangentsoft.com:
https://tangentsoft.com/elec/vgrounds.html

Datasheets

OpAmp ฮผA741 General-Purpose Operational Amplifiers:
https://www.ti.com/lit/ds/symlink/ua741.pdโ€ฆ

Transistor 2N3904:
https://www.onsemi.com/pdf/datasheet/2n390โ€ฆ

Transistor 2N3906:
https://www.onsemi.com/pdf/datasheet/2n390โ€ฆ

The Video

Unidentified Flying Electronics – Disclosing electronics not yet encountered on Earth.