Terrarium 5V for TL072 Question

[Fever2112]

I do not understand the reason to run the TL072 at 5V. Can someone enlighten me?

 

[Robert]

Basically an inefficient method that has hung around since the first prototypes... Initially there were going to be relays, so it made more sense to have the 5V supply.

 

[Fever2112]

For relays I can see having it for a power source but not to power the TL072. So leaving out the regulator is preferred IMHO....

 

[tcpoint]

I tweaked my terrarium to run the tl072 at 9 volts.

 

[Fever2112]

I tweaked my terrarium to run the tl072 at 9 volts.

What did you do?

 

[tcpoint]

I can't remember but I probably just left the 78l05 off and jumpered the in and out and ran everything at 9 volts. The power supply on the daisy can handle 17 volts. (Edit: I looked at my modded Terrarium and that's exactly what I did).

 

[loveforcircuits]

The TL072 normally runs at higher supply voltages. Typical supplies are ±9 V or a single 18 V. At 5 V, input and output headroom become very limited. The TL072 isn't generally specified for such low voltages. In the Terrarium, 5 V may power digital circuitry. Whether the TL072 needs 5 V depends on the schematic.

 

[Robert]

In the Terrarium, 5 V may power digital circuitry. Whether the TL072 needs 5 V depends on the schematic.

It really is just an oversight/leftover... the TL072 should be running on 9V with a diode clamp before the Seed input.

It works fine, but it's not ideal and I wouldn't do it again.