Powering 5v LCD-display with 9v battery. Voltage regulator?

[t]

I've successfully connected a LCD display (**broken link removed**) to my laptop using this circuit: **broken link removed**

The LCD should be powered with 5v and I'm currently using three 1.5v batteries. Now that I'm going to put the circuit in a box, I would like to power it using a 9v battery and I'm not sure how to do that. Will this circuit, http://www.hut.fi/Misc/Electronics/circuits/psu_5v.html work with a 9v battery?

The page says

Power supply voltage: Unreglated DC 8-18V power supply
Power supply current: Needed output current + 5 mA

I'm pretty much a newbie in electronics so any help would be appreciated.

 

[Nigel Goodwin]

All you need is a simple 5V regulator, have a look at the hardware pages for my PIC tutorials, the processor boards include just such a regulator to feed the 5V PIC (and LCD) from a 9V battery.

 

[t]

Thanks for your quick reply Nigel.

I suspected that I should use a voltage regulator but I wasn't sure how to connect it.
If I understand the circuit on your hardware page, **broken link removed**, correctly, you have connected the voltage regulator in a way similar to the page that I mentioned, http://www.hut.fi/Misc/Electronics/circuits/psu_5v.html. The difference is in the values of the capacitors.

Should I connect the voltage regulator like in the picture that I've attached below?

 

[Nigel Goodwin]

Should I connect the voltage regulator like in the picture that I've attached below?

Yes, that's fine - you don't need to use C3, that was just a capacitor added close to the PIC (which is always good practice).

The values are very uncritical, I used 1uF because they are small, and I had them handy. You must use capacitors near the chip to prevent it oscillating.

 

[t]

Thanks for your help!

 

[Sebi]

For 5mA i recommend to use 78 L 05 in TO92 or SOIC8 package.

 

[t]

Like this one? https://www.elfa.se/elfa-bin/setpage.pl?http://www.elfa.se/elfa/produkter/en/2021122.htm

Why is that one better?

 

[Sebi]

Just smaller (case and output current). The 7805 in TO220 pack can handle up to 1A output current, 78 L 05 only 100mA.

 

[t]

I see, thanks for your reply.

 

[Nigel Goodwin]

Just smaller (case and output current). The 7805 in TO220 pack can handle up to 1A output current, 78 L 05 only 100mA.

Most of my tutorials would be quite happy with a 78L05, in fact my 16F877 board uses one - the others used a 7805 'just in case', and because I happened to have them to hand