Bg Micro Backlight Lcd Display

Testing/Troubleshooting
1

Hi everybody.

I have a problem with my Lcd.

It’s a 2x20 LCD from BG Micro website ( here )

Characters are display correctly but the backlight doesn’t work.

The power for the Lcd is +5V : it’s ok

I have made à EL inverter with a pot for the backlight. With -1 to -5 it doesn’t light :frowning:

somebody can help me ?

2

welcome to the board  :slight_smile:

I don’t know if you can dim EL-inverters. I actually don’t think so..

Are you sure that the EL-inverter has the right polarization?

3

thanks you.

for the polarization in my El-inverter it’s like that :

Input : +5

Ground

Output : -5

2 cables (black & white) are used for the backlight.

I tried :

B+(-5) : white

B-      : black

And

B+(-5) : black

B-      : white

Maybe this “reversing” broke the backlight (and I had already try with a positive voltage …) ?

Does the blacklight need more A for the power supply ?

Anybody have this cheap LCD Display ?  ???

 

4

I don’t know exactly what you want to tell me  ::slight_smile:

AFAIK, an inverter has an input (5V in your case, DC) and an output (about 120V AC).

Do you have a Datasheet for the inverter you use?

EDIT:

I’ve just recognized that you’re probably using a wrong inverter.

The inverter you use makes +5V to -5V. That won’t work.

You need a special EL-inverter because the EL-foil needs an alternating current of about 120V

to work.

This is a bit dangerous because of the high voltage, so you have to use some insulation-tape

and/or shrinking hose at the output.

5

sorry for my english … french  ::slight_smile:

My inverter make +5V to -5V.

The datasheet is here http://www.sub-version.net/images/negativeconversion.gif 

but it is not connected like the right part. I have not made modification on the core module, just like this ugly schema.

B+ -----------(+5V)---- [Inverter]------(-5V)----------  |  LCD Backlight  |

B- ------------------------------------------------------ |                        |

6

Je n’aime pas la langue francais… J’étais très mauvaise quand j’avais francais à l’école. Je préfère parler en allemand, mais l’anglais est la langue plus connue et plus facile.  :wink:

My inverter make +5V to -5V.

No. sorry mate but that won’t work.

You need an EL-inverter that makes 120V AC at the output.

Have a look here: http://en.wikipedia.org/wiki/Electroluminescence

(or here  :wink: http://fr.wikipedia.org/wiki/%C3%89lectroluminescence )

you need something like this: http://www1.conrad.de/scripts/wgate/zcop_b2c/~flNlc3Npb249UDkwV0dBVEU6Q19BR0FURTEyOjAwMDIuMDE1ZC5iNTgxYjE0YiZ+aHR0cF9jb250ZW50X2NoYXJzZXQ9aXNvLTg4NTktMSZ+U3RhdGU9NDAwMTM0MjU5Mg==?~template=PCAT_AREA_S_BROWSE&mfhelp=&p_selected_area=%24ROOT&p_selected_area_fh=&perform_special_action=&glb_user_js=Y&shop=B2C&vgl_artikel_in_index=&product_show_id=&p_page_to_display=DirektSearch&~cookies=1&zhmmh_lfo=&zhmmh_area_kz=&s_haupt_kategorie=&p_searchstring=EL-inverter&p_searchstring_artnr=&p_search_category=alle&r3_matn=&insert_kz=&area_s_url=&brand=&amount=&new_item_quantity=&area_url=&direkt_aufriss_area=&p_countdown=&p_80=&p_80_category=&p_80_article=&p_next_template_after_login=&mindestbestellwert=&login=&password=&bpemail=&bpid=&url=&show_wk=&use_search=3&p_back_template=&template=&kat_save=&updatestr=&vgl_artikel_in_vgl=&titel=&darsteller=&regisseur=&anbieter=&genre=&fsk=&jahr=&jahr2=&dvd_error=X&dvd_empty_error=X&dvd_year_error=&call_dvd=&kna_news=&p_status_scenario=&documentselector=&aktiv=&p_load_area=$ROOT&p_artikelbilder_mode=&p_sortopt=&page=&p_catalog_max_results=10

(the black box.)

Technical data:

Folienfläche: 30 - 105 cm² · Ausg.-spg.: 110V/AC · Ausgangsfrequenz: 700 Hz

in english:

size of EL-foil: 30 - 105 cm² . output voltage: 110V AC . output frequency: 700Hz

7

Ok thanks you  ;D

8

Good by EL-inverter.

I used 2 “super bright LED” connected to “B+ / B-” and it looks nice :slight_smile:

It could be a cheap alternative to the classical backlight system.