Simple divider or voltage regulator?

I'm working on a project that will be powered by a PC PSU, so I'll have 12v on Vin.

I am using a GLCD that wants between 6v and 7v to do it's thing.

Now, I'm not sure yet how clean the 12v from the molex is, but was wondering if I should go the route of a simple resistor divider, or use a voltage regulator.

My inclination is towards the regulator, as that sounds like it would give me a more consistent voltage.

Definitely a regulator. A voltage divider is not good for anything except situations where very little current draw is required (e.g. setting a reference voltage to an op-amp input).

-- Beat707: MIDI drum machine / sequencer / groove-box for Arduino

Time to go shopping then :)

Perhaps something like the "1A Positive Fixed Voltage Regulators" at Maplin will do.

The 7806 should work and give you 6V. Do you know how much current your GLCD demands? If it's >100mA or so I'd recommend getting a heat sink too as the difference between 12V in and 6V out on the 7806 will cause it to get quite warm (the excess energy is dissipated as heat).

-- The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons

Datasheet says 200mA at full brightness.

I’ve spotted the LM317 which seems like a nice fit for my needs - it’s cheap and reusable :slight_smile:

I’ve configured it to hopefully output about 6.5V from the ~12V supply, using a 240R resistor paired with a 1kR resistor. (Based on calculations and help from Daycounter)

On the recommendations of a couple of other posts I’ve seen here in the past, I’ve added the capacitors. The DS recommends using Tantalum caps. I’ve not used those before, are they interchangeable with the electrolytic caps I have? The examples in the DS seem to also imply simple ceramic caps are okay for my use-case, but I’m not 100% confident reading that correctly.


Tantalum caps have a longer life than aluminium electrolytics, but for prototyping its not really worth it, they are more expensive.

Cool, thanks. I'll just use my idle electrolytic caps then :)