How to generate Negative powser supply from +5V ? - Electronic Circuits Projects Diagrams Free

octal · 20th January 2007, 09:18 PM

Hi,
I would like to use a controller-less LCD. I have to supply (-19V) (negative power) to LCD controller. How can I generate it ? my circuits is powered by +5V regulated supply (I'm using a PIC microcontroller).

Best regards

**Nigel Goodwin** · 20th January 2007, 09:22 PM

Easy answer! - DON'T use a controllerless LCD, it's far too much work for too little gain.

But to get -19V it would be easiest to get it from the transformer if it's a mains project, for a battery project either an inverter and transformer, or inverter and voltage multiplier (assuming current requirements are low).

Depending on the PIC, you may even be able to use it's PWM module to generate a suitable voltage, check how the PICKit1 generates Vpp.

octal · 20th January 2007, 09:27 PM

Quote:

Originally Posted by Nigel Goodwin

Easy answer! - DON'T use a controllerless LCD, it's far too much work for too little gain.

But to get -19V it would be easiest to get it from the transformer if it's a mains project, for a battery project either an inverter and transformer, or inverter and voltage multiplier (assuming current requirements are low).

Depending on the PIC, you may even be able to use it's PWM module to generate a suitable voltage, check how the PICKit1 generates Vpp.

Thank you Nigel ... but my project is TO create a cheap intelligent controller to this kind of LCD. I have found a set of about 250 LCD at a very very low price (about 3 euro each) and they are 240 x 220 Pixels ... Actually I'm using an external negative power source, and my controller is almost working now. I just need to generate a negative power supply from 5 volt ...
Best regards

Hero999 · 20th January 2007, 10:00 PM

It's called a buck-boost converter.
http://www.google.com/search?q=Buck-...UTF-8&oe=UTF-8

justDIY · 21st January 2007, 04:39 AM

if the -19v is just a micro-current bias voltage, a capacitor charge pump inverter might work too, eliminating the need to rely on magnetics

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Title	Starter	Forum	Replies	Latest
Generate Negative Voltage	Dc5e	Electronic Projects Design/Ideas/Reviews	15	10th September 2008 06:44 PM
create component multisim8	max1000000	General Electronics Chat	1	4th December 2006 04:02 AM
Power Supply Experts!! Need help with KEPCO Labs Power Supply	headbuttking2	General Electronics Chat	1	24th October 2006 02:05 AM
how can i produce a negative supply voltage from +12V?	spyghost	Electronic Projects Design/Ideas/Reviews	15	3rd June 2004 07:05 AM
Power supply/ current supply design	inkedallusion	Electronic Projects Design/Ideas/Reviews	1	17th December 2002 02:10 AM

20th January 2007, 09:18 PM	(permalink)
octal	How to generate Negative powser supply from +5V ? Hi, I would like to use a controller-less LCD. I have to supply (-19V) (negative power) to LCD controller. How can I generate it ? my circuits is powered by +5V regulated supply (I'm using a PIC microcontroller). Best regards __________________ http://www.pocketmt.com the GLCD Font Creator home page

20th January 2007, 09:22 PM	(permalink)
Nigel Goodwin	Easy answer! - DON'T use a controllerless LCD, it's far too much work for too little gain. But to get -19V it would be easiest to get it from the transformer if it's a mains project, for a battery project either an inverter and transformer, or inverter and voltage multiplier (assuming current requirements are low). Depending on the PIC, you may even be able to use it's PWM module to generate a suitable voltage, check how the PICKit1 generates Vpp. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

20th January 2007, 10:00 PM	(permalink)
Hero999	It's called a buck-boost converter. http://www.google.com/search?q=Buck-...UTF-8&oe=UTF-8 __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez

21st January 2007, 04:39 AM	(permalink)
justDIY	if the -19v is just a micro-current bias voltage, a capacitor charge pump inverter might work too, eliminating the need to rely on magnetics __________________ If you don't have a planet, what good are gold bars? want to contact me directly? gmail gordonthree check out my project website: http://projects.dimension-x.net Favorite numbers: 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0