COMPLEX SOUND CHIP 76477

[MrDEB]

Am trying to enlarge the schematic in post 35. As for reading the schematic, I can read it but posting a readable schematic from Dipytace. The schematic in post #35 is pretty much done as it is a redraw schematic from the datasheet. As far as posting the schematic, I am just sharing since the datasheet should be correct (compared with several other similar schematic online. slight differences as to component values and amplifier set up.
Going to recheck my board layout and order two different boards (adapter board and complete circuit) the smaller adapter board for adapting the Sdip 1.7 pitch pins to a 2.54 pitch then I can breadboard before assembling circuit onto the second PCboard.
did some searching and found https://www.pcbway.com/?ad=pcbshopper to be the best price. just hope the quality is there. I wonder if Jonsea is still using Elcrow?

 

[large_ghostman]

So the schematic was from a datasheet? Post a link to it please, DO NOT worry about chopping this or that out at the moment, just post a link to the datasheet schematic you are copying.
Changes can be figured later. What size screen you using? Can use plug the computer into the TV screen?

 

[large_ghostman]

Am trying to enlarge the schematic in post 35. As for reading the schematic, I can read it but posting a readable schematic from Dipytace. The schematic in post #35 is pretty much done as it is a redraw schematic from the datasheet. As far as posting the schematic, I am just sharing since the datasheet should be correct (compared with several other similar schematic online. slight differences as to component values and amplifier set up.
Going to recheck my board layout and order two different boards (adapter board and complete circuit) the smaller adapter board for adapting the Sdip 1.7 pitch pins to a 2.54 pitch then I can breadboard before assembling circuit onto the second PCboard.
did some searching and found https://www.pcbway.com/?ad=pcbshopper to be the best price. just hope the quality is there. I wonder if Jonsea is still using Elcrow?

At the moment you have nothing to make, until you do you wont know the size, until you know the size you wont know how many you can fit on a pcb, until you know how many you can fit on a pcb you wont know where to get said pcb from......................

STOP! Take some drugs, and link me to the schematic, I will ASK you some questions based on this datasheet, YOU WILL ONLY answer the questions I ask. This way we can get it done and save 3TB of HDD space in the process . No go take the ADHD meds and come back with the datasheet link

 

[MrDEB]

here is the circuit I am using.
https://commons.wikimedia.org/wiki/File:76477_Demo_Circuit-D.JPG

 

[large_ghostman]

Great, can you also link the datasheet please, then give me a couple of days to clear a couple of things I am doing.

 

[MrDEB]

here you go. Just went google/sn76477
https://en.wikipedia.org/wiki/Texas_Instruments_SN76477
**broken link removed**

 

[large_ghostman]

Thank you

 

[large_ghostman]

Ok not forgotten this, i have ordered the chip to try something for you. I might have a nice way to get rid of some of the switches and make it more fun for kids and cut down the cost a little. When I have the part (hope early next week) I will post, I will post a schematic at the same time so everyone can read it, then you can copy to dip trace and just that for yourself.

 

[JonSea]

This could be a fantastic project, especially if the 20-some switches and 10 or so pots are laid out in a logical sequence so the operation makes sense (i.e., related controls are grouped together). This will require a large panel for a workable arrangement.

If I were doing it, I would want a large circuit board for all the controls. Soldering pigtails to switches and pots is something I hate - reliable results require a lot of effort. If I used pigtails, I would use separate 2 or 3 pin cables (as needed) to connectors on a circuit board. MrDEB's idea of a ribbon cable from a dual-row header fanned out to different switches and pots has never worked well for me; the conductors are too fine and won't take much abuse while getting everything wired up.

I look forward to seeing LGM's simplifications...and later his microcontroller interface <g>

 

[MrDEB]

The layout for the switches and other panel mounted hardware was originally going to be on a PCboard but each pot and rotary switch each have two wires connected, A ground and a connection to the chip. Had a board schematic using ribbon cable etc. but cost went up as well as PCB real estate. Basically same idea as Jonsea suggested.
Plan to use rotary switches https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2167322_-1h
then solder each resistor or cap end to each pole and the other end to the second gang common. The connection from the board to the "A" common and the "B" common back to the PCboard.
Two wires instead of 8 for a six position switch.
As for switches, I found on Ebay Bay 24 switches for $7
When I order the boards, if LGM wants a board, I would be more than happy to send him one but need address.
Looking at my present schematic, I see 25 wires from PCboard to panel hardware.

 

[JonSea]

Looking at the data sheet for the switch you specified, there are a couple of issues:

1. This switch has PCB pins rather than solder lugs. If you're going to connect components directly to the switch, solder lugs will work a lot better.

2. This switch is non-shorting. That means when changing positions, the circuit is open when switching between positions. If the sound is playing when the switches are switched, there will be a pop each time the switch is changed. Better would be a shorting switch, where the contacts are make-before-break - when switching the two contacts are shorted together when switching from one position to the next. Instead of an open-circuit transition and a big pop, the transition won't result in an open circuit condition and little interruption during switching.

 

[MrDEB]

I looked at the data sheet couple weeks ago and when a person places an order the data sheet specifies type of pins, shorting etc. but thanks for looking at it. The part number I deciphered is KC (24,25 or 26) B3001SLS Model#, actuator, actuator length, bushing, timing, termination, contact material
here is a look at my pcboard at this time. I find if I let it ferment awhile I get a fresh look and find errors. Did the same when searching for rotary switches and drawing schematic.

 

[MrDEB]

hopefully these files appear correct as I saved at 300DPI . Tried uploading without

 

[JonSea]

I looked at the data sheet couple weeks ago and when a person places an order the data sheet specifies type of pins, shorting etc. but thanks for looking at it....

Yeah, the switch is available in a number of configurations. The switch Jameco is selling is the configuration I have pointed out.

 

[JonSea]

Why would you zip a pdf? The zip file is probably larger than the original.

Maybe you'll get a clue if I say it again. Don't zip compressed image files.

Do your drawings look any better? Can't say. I'm not going to the trouble of downloading and unzipping them.

 

[MrDEB]

I tried uploading unziped but I got an error. Thinking maybe saving in bitmap at 300DPI then upload to photobucket.
I didn't want to compress the file but ??
The switch I posted was from Jamecos catalog and thank you for pointing out about the shorting/non-shorting. Didn't think about creating a thug when rotating the switch.

 

[MrDEB]

Alright lets try this. I decreased the image (pixel count)
this looks like it might work hopefully.

 

[Mikebits]

Gadzooks
Is there any particular reason you choose to not use the upload button as shown in image? What ever way you are doing it, it is making me open up a image viewer to look at the file, so I just hit cancel.

 

[JonSea]

MrDEB,
Once again i have reached the point where my phone is in danger of being thrown across the room.

I gave you a link to a 5 page forum thread where people explained step-by-excruiating-step how to post a readable schematic, yet for some reason you're trying to re-invent the process again.

The reason you couldn't upload the latest attempt is that you saved the images as BMP, which is a non-compressed image file. If you had saved them as JPG, a compressed file, they would have uploaded properly. This has been discussed to death in that previous thread I menrioned.

Here are a few hints:

1. Look at the file size before you upload it. If it's huge, you don't have the right format. Use JPG.

2. After you upload it, look at it . If you can't easily read it, just delete it and try again.

3. Go back and follow the previous thread I linked. This has all been explained before.

 

[JonSea]

That "look at it" part? This is what you'd see.