In dealing with a Matrice of switches, the best that comes to mind is the present readily available LED Matrice circuits, if only one could replace the LEDs with some type of Optical Switch or for that matter any switch! Then one could easily benefit from their existing software etc.

Please advise if this is possible at all and if yes how?

thanks in advance

 

Hello,

Do you have the schematic of the current situation?
Then we can have a look how to adapt it if possible.

Greetings,
Bertus

 

Hello,

Do you have the schematic of the current situation?
Then we can have a look how to adapt it if possible.

Greetings,
Bertus

Would this be a reasonable example(basically any LED circuit would do)?
thanks

http://www.bowdenshobbycircuits.info/60sec.gif

p.s.
there's also this one.
60 Light Sequencer using a Matrix

The circuit below illustrates using a 10x10 matrix to sequence up to 100 LEDs with just three ICs and 20 transistors.

http://www.bowdenshobbycircuits.info/page5.htm#60sec.gif

Although the above says sequencer, Vs. my need to turn LEDs/Switches OFF/ON based on any predetermined pattern.

 

Hello,

You can put the leds of an optocoupler in series with the origenal led.
The voltage drop will rise about 1.2 volts by doing this
(the IR led has a voltage drop of about 1.2 Volts).

Greetings,
Bertus

 

Bertus,
Thank you so much, that makes a lot of sense. Now I have the following 2 questions:
1- Can't the LEDs be replaced with the optocouplerto accommodate the voltage drop?
2- Since the LEDs are turned on and off by a series of pulses(or frequency change or what not, since I do not know how they work), would these short pulses cause any problems in the optocouple? Like they would be turning on and off with every pulse?

please excuse my lack of knowledge of electronics.

 

Hello,

The leds can be replaced by the leds from the optocouplers.
You will have to limit the current by placing a resistor in series with the leds.
The maximum current can be found in the datasheet of the corresponding optocoupler.

Greetings,
Bertus

 

Thank you Bertus,
This seems just great, after all an optocoupler is indeed an LED itself! Now to my other question and sorry for being so lame in this subject.
I was told the LED is turned ON/OFF like 24 times/second? How would that effect the optocoupler? Would it activate the optocoupler switch 24 times/second too?

grateful for all your help

Cy

 

Hello,

Yes, if the led is switched 24 times a second, the transistor in the optocoupler will switch also 24 times a second.
Speed is of no consern here as there are optocouplers that can switch even in the kHz range.

Greetings,
Bertus

 

Bertus,

Thanks for the help. I'll go and try this out and keep the forum posted on the progress.

Best wishes

Cy

 

Please check out this simple LED circuit and advice on how to replace the LEDs with Optocouplers.
The Optocouplers will be used to activate solenoids that are fed off of a 24v supply.

thanks

 

Is the circuit shown above Charlieplexing or Multiplexing or neither?

 

Hello,

The circuit shown uses multiplexing.
The row must me low and a colum high to let the led burn.

Greetings,
Bertus

 

Thanks again Bertus,
Can I just go ahead and replace the LEDs with Optocouplers? Or do I also need to add resistors, diodes etc.?

Is multiplexing preferred to Charlieplexing?

appreciate your help.

 

Hello,

There are already 330 Ohms resistors in the schematic.
This value is dependend on the led characteristics of the optocoupler.
There is also a limatation at the controller side.
I do not know how much current an out put of the controller may deliver.

Greetings,
Bertus

 

Hi Bertus,
Thanks for the quick reply.
I'm going to try with PC817 and/OR P521. I'll just do some trial error and hopefully get it right.

cheers

 

Hello,

330 Ohms = 0.33 kOhm.
Color code orange,orange,brown.

See also this page:
http://www.diyaudioandvideo.com/Electronics/Color/

This is a link from the EDUCYPEDIA on component coding:
http://www.educypedia.be/electronics/datacomponent.htm

Greetings,
Bertus

 

Hello,

330 Ohms = 0.33 kOhm.
Color code orange,orange,brown.

See also this page:
http://www.diyaudioandvideo.com/Electronics/Color/

This is a link from the EDUCYPEDIA on component coding:
http://www.educypedia.be/electronics/datacomponent.htm

Greetings,
Bertus

Thank you so much, I am learning a lot here.

 

for other noobs like myself...

http://www.doctronics.co.uk/resistor.htm