Audio Video switching

[jbelectric777]

Hi everyone, I made a drawing of what I wanna do andif you guys can look at and tell me if it will work I'd appreciate it. We have 2 games 1 VCR and1 DVD player and always changing the AV cord. The drawing doesnt show all exact connections like 0V and 9V but shows basically what I wanna do.

The left side output is common to the television, Its not showing but the IC is a 4017 decade counter controlled by a momentary push button, when the button is pushed I want it to cycle thru the counter, when it hits 5 I want the IC to reset, so output on the 4017 will energize 2 pole PCB relays and the selected one will connect the right input to the common. Will it work like this ? Any suggestions ? Thanks, Jim

 

[jbelectric777]

I forgot to say the 4 green LED 's are connected in paralell with the 4017 outputs.

 

[mbarazeen]

Will it work like this ? Any suggestions ?

if you wire everything right it will work no doubt, if you use relay you have to have a driver transsistor in between not to over load the IC. also make sure to add de bouncing circuit to the push butto, otherwise you will experience random selection.

rather than mechanical relay you can use 4016 ICs to switch the selection see the data sheet bellow

CD4016 Datasheet pdf - Quad Bilateral Switch - Fairchild Semiconductor

 

[irbirb]

you might have to use a dual power supply for the 4016 to deal with the audio no? and then i wonder if you wouldn't need to clamp the video signal (black level restore) also.

perhaps relays will be better for what you want, especially if you just happen to have some laying around.

 

[jbelectric777]

instead of de bouncing can i use a hard single pole toggle instead ? it doesnt matter because the relays not holding the coil in, the NPN will be doing that from the chips own latching output. i know what you mean about bouncing, they are very sensitive.

 

[crutschow]

you might have to use a dual power supply for the 4016 to deal with the audio no? and then i wonder if you wouldn't need to clamp the video signal (black level restore) also.

You don't want to mess with the video signal, just pass it through unchanged. Any black level restore is done in the display.

 

[jbelectric777]

ok, so use NPN's off the 4017 and de-bounce the contacts. anyone know what value to use ? 2.2uf cap 1KΩ damper resistor ? do i need a buffer after the de-bounce ?

Thanks

 

[jbelectric777]

How about using a 555 timer ( i have one ) pushbutton charge capacitor and will trigger at 2/3Vcc then discharge (zero on time )

I drew another one for you to see.

 

[mbarazeen]

ok, so use NPN's off the 4017 and de-bounce the contacts. anyone know what value to use ? 2.2uf cap 1KΩ damper resistor ? do i need a buffer after the de-bounce ?

Thanks

you can use the value...time constant is not a concern for your requirement.
no need 555...
for 4016 you can use single supply no need dual...or use relays... put a resistor before connecting 4017 out to transistor base

 

[jbelectric777]

so you are saying that using 1000 ohms and 2.2uf capacitor is enough for switch contacts de-bouncing and no need for anything else, except you want me to put a resistor in the line in between the 4017 output and the transistor base for each relay coil, not a problem, thanks a lot much appreciated.

 

[jbelectric777]

i got the buffer thing md thanks, i only need to worry about the random outputs possible so im going with a cap and resistor dont need the buffer, i thought u were saying i needed an ic that would switch on a timed amount, no problem i got it and thanks again.

 

[audioguru]

Your English and spelling are so bad that I will not read them anymore.
Why can't you type in real and good English? Or maybe because you are a little kid? Recently from a foreign country?