LCDInfo.com

http://www.lcdinfo.com
It is currently Thu Dec 14, 2017 6:22

All times are UTC + 2 hours




Post new topic Reply to topic  [ 18 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Sun Dec 08, 2002 19:37 
Offline

Joined: Sun Dec 01, 2002 21:30
Posts: 24
Okay here is some sircuits for powering lcd displays. Most of these will give negative 9-12V, but there is also some that give -15V or even up to -48V.
All of these works from +12V

http://www.p5taylor.btinternet.co.uk/11.pdf

http://www.reconnsworld.com/power_voltinvert.html

http://w1.859.telia.com/~u85920178/power/vconv_01.htm

http://www.hantronix.com/down/neg-invr.pdf

http://www.aaroncake.net/circuits/vinvertr.htm

I'm using one of those 555 based sircuits with an additional 7909 regulator and it seems to work fine.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 08, 2002 22:31 
Offline

Joined: Sun May 05, 2002 22:05
Posts: 2063
Location: Lappeenranta, Finland
Thanks, I'm sure these will be useful. :D


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 08, 2002 23:05 
Offline

Joined: Sun Dec 01, 2002 21:30
Posts: 24
Your welcome. Here is one more(ICL7660 and ICL7662) this has almost 100% conversion effiency!
http://www.intersil.com/design/parametric/productresults.asp?t=55&i=216&i=219&i=1045
You only need this chip and 2 capasitors. Cannot go much easier :D

Those are also quite cheap about 2-4€


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 08, 2002 23:30 
Offline

Joined: Sun May 05, 2002 22:05
Posts: 2063
Location: Lappeenranta, Finland
Spark wrote:
Your welcome. Here is one more(ICL7660 and ICL7662) this has almost 100% conversion effiency!
You only need this chip and 2 capasitors. Cannot go much easier :D
Those are also quite cheap about 2-4€

That sounds very good. With the chip and 2 caps it would be a very easy way to make the negative voltage.

Do you know where to get these chips easily ?


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 08, 2002 23:51 
Offline

Joined: Sun Dec 01, 2002 21:30
Posts: 24
http://www.spelektroniikka.fi Suomalaiset voi katsella tuolta.
Tarvii vielä etsiä josko löytyisi jokin toinen paikka.
For those of You that doesn't live in finland You can find these ICL7660 and ICL7662 from RS-COM http://www.rswww.com
There probaply is other places, but I dont wanna go thrue all those. Then there is also Intersil's own webshop, but i dont know do they deliver for end user. You could always try.


Top
 Profile  
 
 Post subject:
PostPosted: Mon Dec 09, 2002 1:36 
Offline

Joined: Thu Oct 24, 2002 2:24
Posts: 64
Location: Lisboa , Portugal
Thanks for the Links :wink:

The one i'm using uses 3 voltage regulators and some capacitors , it has been designed by me to powerup the lcd externaly , it uses an 2 x 24v 3VA Tranformer to get the midle point has ground , then after the rectifier circuitr contitued by a rectifier bride ,two 1000 uF (one for eache chanel), 2 100 nF capacitor's rigt after the 1000uF , then comes the voltage regulators for 5 v (7805) , and the voltage regulators for -20 (7920) and the -8 (7908) right next come two more 10 uf cacpcitors , betwen the Vin and Vout if The ic's there is also an diode to prevent short's ans inverse curent's , it's also a very cheap and functional power suply , i've already head of those chips , but due to my display need of -20 volt i've made one off these , all componentts are easy to find and very cheap (about 8 € including the circuit board)


As soon i have the schematic done i'll post it here in eagle format :wink:

Samtech


Top
 Profile  
 
 Post subject:
PostPosted: Mon Dec 09, 2002 13:30 
Offline

Joined: Sun Dec 01, 2002 21:30
Posts: 24
Your welcome. Here is few voltade doubler sircuits. Other is made with ICL7660 and I believe it might be possible to do an inverting voltage boubler with one icl7660 or 7662 chip.
I just ordered that ICL7662. Altought my 555 based inverter worked fine. Just want something that doesn't have so many components.

http://www.diystompboxes.com/pedals/vdbl.html
http://www.reconnsworld.com/power_voltdoubler.html


Top
 Profile  
 
 Post subject:
PostPosted: Tue Dec 17, 2002 22:02 
Offline

Joined: Sun Dec 01, 2002 21:30
Posts: 24
Just little note for useng those icl7662. There might be the need of use some external stabiling for examp. Zener diodi. You could also try to change that output capasitor.
I used resistor and zener diod. With out those my lcd goes crazy when I adjust contrast. :D


Top
 Profile  
 
 Post subject:
PostPosted: Thu Jun 26, 2003 4:47 
Offline

Joined: Thu Jun 26, 2003 4:18
Posts: 3
Hello,
which things I would need to get on the cheapest and simplest way
-24 Volt from a ATX Pc suply ?
that´s the last thing to connect my lcd

thx


Top
 Profile  
 
 Post subject:
PostPosted: Thu Jun 26, 2003 7:50 
Offline

Joined: Wed Jun 04, 2003 20:05
Posts: 3
DC/DC-Converter SIM1-524S.

Look here: http://www.reichelt.de/index_direkt.html?SIM1-0524S%20DIL8+PpK-x9S4AQ4AAHWFQYY+D481.

It's a german shop but you should get this (or a similar type).


Top
 Profile  
 
 Post subject:
PostPosted: Thu Jun 26, 2003 13:53 
are you shure thats it
I need negative -21 Volt


Top
  
 
 Post subject:
PostPosted: Thu Jun 26, 2003 14:09 
Offline

Joined: Fri Dec 13, 2002 20:24
Posts: 13
you could also use a LT1051.with 5 parts you can get the negative voltage out of a pos. 12 volts.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Jun 26, 2003 17:05 
Anonymous wrote:
are you shure thats it
I need negative -21 Volt


Simply connect the positive output to ground and at the negative you have the -24V. Input and output have no connection therefore you can put Vin- and Vout+ both to ground.


Top
  
 
 Post subject:
PostPosted: Wed Jul 02, 2003 17:09 
TI provide a built-in componant to do it alone :



http://focus.ti.com/docs/prod/productfo ... ber=PT5023


Top
  
 
 Post subject:
PostPosted: Sun Aug 03, 2003 12:17 
stef wrote:
TI provide a built-in componant to do it alone :



http://focus.ti.com/docs/prod/productfo ... ber=PT5023


WOW expensive thing euro 27 without the tax at Farnell, for the -12 volt version. Very handy though.


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 18 posts ]  Go to page 1, 2  Next

All times are UTC + 2 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group