Jap's electronic projects

Audio-video switch

designed by Jap


This is an 8-input x-output audio/video switch module to be controlled from a computer, for example from the parallel port. Each audio/video output can be switched to any of the 8 inputs, separately. One module drives one audio/video output and has a 34-pin connector to plug into the system interface.You can use video OPA-s on the 4051 output instead. Note that you can get full integrated video multiplexers from Maxim.

Schematic diagram

WARNING: the drawing has been updated and The circuit uses 5VDC as VCC and -7VDC as VEE. The video inputs are terminated to GND by 75 ohm resistors.

comments on this page:

posted by Robert Furlong on 2003-02-22 10:05
This is the type of application I'm looking for. I need a PC controlled device to turn on/off the VGA signal to a projector. In fact, the version that you are looking at to use the serial port is ideal for my application. Did you write the controlling software in VB ? Do you have some software that I can look at ?




posted by ana m on 2003-01-30 12:29
can u give me some of ur MPU based design Project coz i cant find one that is much cheaper but really great. plssss.....

posted by hamayoon amin on 2002-12-26 13:16
i am doing a project at home and would like if you can help me with some other projects which i could do.

posted by Isaac Edward on 2002-11-19 09:43
If you please send me FM transmitter circutes 3w to 4w with its details

thank you
isaac edward

posted by Vanidasan on 2002-11-11 10:06
Dear Sir,

I'm looking for a 15" Monitor circuit diagram and working details of the monitor but i found most of the site's are in Russian, Can i expect some kid of help on this


posted by bikk on 2002-10-21 09:42
Mi a k?

posted by Jeff on 2002-10-09 09:54
where can i get the CN RCA

posted by Jacky on 2002-09-22 13:45
hi there! i really need your help. can you please send me a MPU based design project with documents and datasheets? i really need it. our deadline is on wednesday. pls help me...

posted by HELENO ALVES DA SILVA on 2002-09-09 03:03
Gostaria Que se Posivel Mandar Alguns Exemplos Sobre Atmel AT29C040A e AT28HC256E Grato Desde J

posted by Lica Adrian on 2002-09-06 23:19
For the av/switch controlled by paralell port where is the soft because im very intrested in this schematics.by the way thanks for existing for your help in electronics.thanks.

posted by ian on 2002-08-30 07:40
I am an electronic engineering student requesting information about the caller ID on TV screen.Please send me the documents and other related topics including the schematic diagram. THANK YOU!!!

posted by hamid on 2002-08-20 08:33
please sent me another circut that you can.

posted by ROSITCA REMUS on 2002-08-02 21:14

posted by www.sakag.net on 2002-07-13 02:50
This plan is great

posted by ojok kenneth on 2002-05-24 12:59
How can one get the chip max 4051

posted by Cornel Barsan on 2002-05-19 21:37
Revansa Daciei www.armentarius.i8.com

posted by mehmood-ul-haque on 2002-03-27 10:05
Dear Sirs,

i like this page....because it help me for solving my project.
You are wonderful !!!

posted by sakag on 2002-03-15 03:16
Hello Jap

Fine stuff you make
Go on......


posted by Joe McMinn on 2002-02-03 21:34
Wow you have saved my career

Thanks Loads!

posted by DERRAR on 2002-01-30 19:35
et merci d,avance

posted by benny on 2001-12-01 06:32
i like this page....because it help me for solving my project.

posted by Behcet Berber on 2001-10-25 18:50
This page i`ts wery good

posted by Mustafa on 2001-10-20 11:31
You are wonderful !!!

posted by Liu Fu on 2001-07-25 05:09

Dear Sirs,
The attachment is our application block diagram of Video switch,kindly please send your detailed datasheet and quotation of video switch
which is suitable for our requirement to me if you have it ,or have your distributors in Singapore to call me at 65-7996740


Liu Fu

posted by jap on 2001-07-20 17:14

The 8255 control bus can be directly connected to the PC parallel port. The first switch exactly was connected this way. But when you reboot the PC, the switch states will be reset, so a next version is already planned on paper with serial connection and on-board microcontroller.

The next version of the switch uses max458 for switching video, max382/cd4051 for audio.

posted by D.subramaniyan on 2001-07-11 21:36
this is very useful to me and every (EL) people,please give same setup using with out (PC) & give video AMP circutes, thanks for ever

posted by Rad Cornel Dan (Romania) on 2001-04-12 23:42
This page i`ts wery good .
Thank you wery much !

posted by USMAN AZMAT on 2001-01-21 11:15

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