4 PORT EXPANDER CARD AND CONTROLLER

 Here we go again with another circuit addition to our Mixer/Console.

Buckle up dudes and dudetts, this may be a long one.

Since we MAY need more than 6 Inputs, we found a way to add more without taking up too much space.

We use an expander board.

This circuit will be wired up to feed up to 4 stereo feeds into ONE Input.

You can also use it in REVERSE to route up to 4 stereo feeds from any output. 

I built two of these for the dreaded rat invested Console I built many years ago. (see CHAPER ONE )

The 'toggle' switches on the top of the module were used to SET the timer/clock.

I found the LATCHING switches on EBAY.  I added some LEDs to show what switch was pushed in. To the left is the actual relay boards. (More on that to come)

Useless fact:  The original mixer concept called for "modules" rather than a large top that opened up. This idea was scrubbed when the folks at Radio Systems sent me a complete top. They had a program where a customer could have their top replaced by a newer and more modern top. And they took pity on this old dude and sent me one of the older "trade ins."

In other words, your older style RS Series Console

would turn into a nicer looking more modern "Millennium" console.

They got the idea of scrapping the mechanical (wafer type) push switches.

OK, enough B.S. Let's get back to why we are here.

I did build two of these units for the original mixer, but I think only one will be needed here. JLCPCB has a 5-board minimum, so I will have extra boards. Might as well make two.

If you look closely at the main board, you will see that J-1 & J-2 are wired in parallel. The extra connector would power a 2nd expander if you needed it.

The little expander boards worked well. Except for ONE issue. The switches would get dirty and make poor contact, causing the relays to drop out.

Here is where we depart from the OLD design and re-do a few things. Why you ask?

The switch problems were one of the few drawbacks to the older RS console design.

In the RS Console I installed at the radio station (1995) I continually had to replace switches. In all fairness, the problem was usually caused by heavy handed DJ's who never knew how to treat equipment properly.

This console was not designed to take a ton of abuse.

So, we are going to try to eliminate all the mechanical switches and use I.C.s instead.

Let's take a look at the schematic for the main expander board.

The 4 additional inputs come in via TB2 & TB3 and is routed to Relays K3, K4, K5, & K6. The output of those relays is then routed to relays K1 & K2. The proper relay configuration is selected via the switch panel J1. I will show that in a bit.

Here is how my new board will look like.

Component placement

Bottom Copper layer

Top Copper layer
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OK, now onto the controller.

Here is how Radio Systems controlled their expander board.

Note: R4 is a ZERO-ohm resistor. It is used as a "jumper" on their switch bank controller. J1-1 goes to +15 V.

You will also note that 'Select A' is not hooked up to anything. That is because "A" is the default selection. In other words, ALL the relays are 'relaxed' or non-energized.

The Radio Systems controller card was also used as a Timer Control. The only difference is what components are mounted with the switch. This way, they only had to keep ONE version in stock, then loaded the appropriate diodes or resistor.

You can see the additional 'holes' for components. I am showing my spare Timer Controller as I do not have a 4-port switch bank. But you get the idea, right?

Now, since we don't like the switches (and I haven't even mentioned how hard it is to get a square hole into a panel) we are going to REPLACE them with I.C.s. (we hope)

We did not show that the switches are fed with +15 V and the switches then send that +15V to the card. 

So....If we develop a 4-digit counter, then feed the +5v (High) to a transistor, we can turn on the transistor and feed +15 V to the card.

Right? 

Right?

So, let's start searching....................

OK, first up, I want to build a circuit that will light 4 LEDs in sequence then start over. That will give me the +5V to turn on a transistor. I really liked the 4017 CMOS chips we used when we were building the 1 sec. timer that drives clocks. So, let's search there.

I can also use this idea when it comes to building up the "Monitor and Headphone Control" cards."

I am back!!! I found 4 ideas I want to try.

 

Let's go to the breadboard and build up diagram A.  OK, Now for B.

And C.   Let's not forget D.

C was the winner winner, circuit dinner. (Too much Diners Drive Inns & Dives,)

I played around with A, B, & D and never got them to work as advertised.

Let's take a look at the Breadboard.

And we can watch it work !!!!

Only issue is with this circuit you press the switch 5 times. On the 5th push it shows NO lights. Then you press again for #1.

The circuit I found needed a slight revision. The original builder may have needed a "blank" setting, but I do not. 

Let's try THIS version on the breadboard.

I think we may have it.... No not really. Please follow to the end.

We can now try it out !!!

Let's see if we can drive a transistor with this circuit.

First effort started out great then went to hell with exploding transistors and HOT I.C.s. Not a fault of the circuit, but the nut building it.....SO until Amazon comes with deliveries, we will work on something else.

Now that we have spare parts, let's try this again.

This is where we all hum the theme from "Jeopardy".

OK, now that we have all that crap a workin', let's do some switch work.

Even using a tackle switch, the circuit may not be stable due to switch bouncing. A capacitor helps but I think we might be better off going a different route.

On the RS console input boards, they used nice switches to drive a 4011 chip.

And I have a TON of their nice switches.

I know what I said about square switches and mounting. But these have a little 'rims' around them that makes the mounting task a bit easier. The downside to these is they use incandescent bulbs that run on 15 volts. If I can't use the +15V from the transistor, I think I can just add another transistor. They did offer some LED "replacements" but they were not bright enough to suit me, and also worked on +15 V. We shall see how this develops as we go along.

Well, the Radio Systems nice switches did work well. I like the larger size.

BUT,

I went through some other switches and found this one from ALL ELECTRONICS (Part # MPB-35, and they are 3 for .99.) They also have a nice LED inside that I can light up... I scored a bunch of them.

I tried one of these hooked to the 4017 counter and it worked FLAWLESSLY. I bet I ran through 100 cycles, and it never bounced once. 

You can choose your own type of switch depending on your design.

So, let's continue with the controller.

 Let's take a look at how this idea will come together.

Here is what I came up with.

Let's go through the diagram. The 4017 chip is a basic counter chip that you may remember from our clock circuits. I want to send a +5 V pulse to Pin 14. That pulse comes from an outboard switch that goes to J-1. The counter will count 1 step with each push of the button. When you step from #4 the counter re-sets to # 1. LED D1-4 shows where the count is. 

Now that we have 4 outputs, we need to get them to switch +15 Volts that will go to the Expander board to energize the proper relays.

I found that I could easily switch a ground pulse by using a 2N4401 Transistor. I need that ground pulse to fire off a PNP transistor that will switch the +15 Volts. The +15 Volts is then fed to the Expander board control inputs.

Let's look at the Counter.

This shows the count on # 4. I used one of my smaller switches (see above) for the breadboard version.

Now see it work!! I know, we already did this once... But this is fun!!

Now, let's hook up some transzippers.

The green LEDs show 15 Volts leaving the output trans. I used those so we could see it in action. They are not really needed in the final design.

One the far right is a 2n4401 transistor. When it turns on, it turns on the transistor immediately to its left (2n3904) by giving it a ground. That transistor feeds the +15 volts to the connector. That voltage then goes to the expander board.

Let's walk through how it magic happens.

The output from the 4017 goes through R6 and enters the 2n4404 Base. (Q1) That turns "on" the transistor, and the ground flows through the collector and out of the emitter.

The output of the 2n4401 goes through R9 and into the 2n3906 at the base. (Q-4) The collector is wired to the +15 volts. When the transistor turns on, the 15 volts exits the emitter and on to the expander board.

"Hey Mister Engineer, why are there only three outputs going to the expander card ?????"

 Remember, count #1 means nothing. That is a default setting with all of the expander relays relaxed. So, no voltage is needed.

I did hook up one relay. (unseen) You can hear it 'click on and off' in the video.

OK, now for some "adjustments."

I decided to use the larger switches that I had from other RS Consoles. It is a lighted push button, and I can add a couple of connections and light it up. I did that with the small switch as well. It won't track the switching but will look cool.

We can also mount some separate LEDs to show where the count is.

Here is the revised schematic. You will notice some "Power Flags" on the drawing. They are only there to let KICAD understand what I am doing, so it does not "error". They are not part of the schematic in the real world.

It worked like a champ, so I then took the nice Radio Systems switch, (Dial Light) found a bulb and hooked it up. Here it is on the bread board. 

It's not as bright as it looks. Now we can let this cook a while, so we can start on a circuit board for this part of the show.

And here is the board for the Controller.

And the 3-D view

I made a couple more changes in the board design, by flipping some LED's and connectors to the reverse side. You will see why when we mount it all up. Trust me.

Now that we have our design and the parts from Amazon, let's build up the prototype. And check our board design at the same time.

That's next time. See you then. I think it's time for a refreshing adult beverage.

You may now proceed past go, collect your $200.00 and land on the Next Chapter.

  YOU CAN NOW MOVE ON TO THE NEXT CHAPTER ---- BUILDING THE EXPANDER PROTO TYPE

God Speed Mother Nature.

Live Long and Prosper

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The information presented here in this web site is for personal use only and may not be

 used commercially

We make no claim as to the accuracy of the information with-in. 

CHAPTER 10 - - - CONSOLE TIMER

 CHAPTER 10 - CONSOLE TIMER

Now that the two clocks are finished, let's move on to the TIMER.

It is the easiest to build.

We decided on ONE board for this timer that will go inside the console itself. 

We also decided on smaller Seven Segment Displays (.54" vs the 1" we used on the clocks.)

There is no need for a controller, as all we will be doing is re-setting the timer to 00:00:00 and let it count.

For a reset, our console module will provide a "HIGH" when ever you push the Channel Button. (More on this later).

So here is the diagram for the Timer.

The timer works just like the clocks, only we use 3 of the 60 MODS

This will be a 60 hour counter. I can not imagine needing more. If you want a 100 hour counter, just leave off the 4081 section feeding the hours module. (U-5C)

The timer is re-set via a relay that closes when it receives a 'high' (1) from the console. The relay contact goes though 4 diodes that will feed a momentary +5 V to the re-set pins.

Easy Peazy. Bob's your uncle.

You build this the same way that you made the Clocks. Place the components, run the busses, and then wire it up.

Don't forget to TEST as you go along.

Everything 'should' work as designed. If so, let's go ahead and order the circuit board from JLC Pro.

Here is the blank board we got.

Let's stuff some parts, starting with the counter circuit and the seconds part of the timer. 

When that is verified as working, move onto the seconds section, then the minutes.

There you go, one timer ready to mount in the Mixer Panel.

We will now set this aside, and forge ahead.

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Some final thoughts on the clock/timer.

It was hard to get it to come together, but well worth the effort. 

Yes, I could have used a PIC/PUC or whatever they are called. Or an Arduino. Or even a programmable chip.

But I love CMOS and I am an old fart.

I ran into on LARGE issues with the finished board. When I hit the "reset", all the digits returned to 'zero" EXCEPT for the 'minutes' digit. It would always land on "1".

So I went back to the bread board to see if I could figure it out. For some reason, adding a resistor to the output of the 4018 solved the issue. I also added a couple of diodes. (The schematics and pictures do MATCH the fixed version.

I tested a wide variety of circuits. 

And yes, I had a few failures and changes in the designs.

But now I have 2 digital clocks in my Ham Shack. (one set to GMT, the other set to LOCAL time)

And a timer for the console.

I learned and relearned a lot of things doing this phase.

But I am glad it's over.

I hope you got as much out of it as I.

So now we have our clocks and timer completed and "running like a clock', we will move on.

It's time to check the clock and timer off of our Planning List.

MIXER PLANNING

1) POWER SUPPLIES

+/- 15 VDC XMFR 1

+/- 7.5 V DC XMFR 1

+ 5.0 VDC (CLOCK/TIMERS) XMFR 2 OR COMMERICAL UNIT

SCHEMATICS

CIR BOARDS

CABINET

2) TIMER / CLOCK - SEPERATE UNITS FROM MIXER DUE TO SPACE LIMITS

12 HOUR MOD 60 MOD 60 MOD 12

24 HOUR MOD 60 MOD 60 MOD 23

TIMER UNIT

RE-SET PANEL

DISPLAY BOARD SCHEMATIC CIR BOARD

MAIN BOARD SCHEMATIC CIR BOARD

60 SEC/MIN MOD SCHEMATIC CIR BOARD

23 HOUR MOD SCHEMATIC CIR BOARD

12 HOUR MOD SCHEMATIC CIR BOARD

CABINET

PROTO TYPE

FINAL

3) HEADPHONE AMPLIFIER

DESIGN

SCHEMATIC

PROTO TYPE

CIRCUIT BOARD

4) CUE AMPLIFIER

CAN ALSO USE AS A TEST AMP WHILE BUILDING AUDIO BOARDS

DESIGN

SCHEMATICS

PROTO TYPE

CIRCUIT BOARDS

5) POWER AMPLIFIER (REPLACES TASCAM PA-30)

DESIGN

SCHEMATICS

PROTO TYPE

CIRCUIT BOARDS

6) OUTPUT BOARD

DESIGN

SCHEMATICS

PROTO TYPE

CIRCUIT BOARDS

7) MONITOR SELECT

DESIGN

AVOID OLD STYLE SWITCHES, USE DIGITAL

SCHEMATIC

PROTO TYPE

CIR. BOARD

8) PGM / AUD / MONO SELECT

DESIGN

AVOID OLD STYLE SWITCHES, USE DIGITAL

SCHEMATIC

PROTO TYPE

CIR. BOARD

9) INPUT SELECT

DESIGN

AVOID OLD STYLE SWITCHES, USE DIGITAL

SCHEMATIC

PROTO TYPE

CIR. BOARD

10) AUDIO INPUT BOARD

DESIGN

RS-12 VERSION

SCHEMATIC

PROTO TYPE - NOT DOING A PROTO TYPE

CIR. BOARD

11) MONITOR BOARD

DESIGN BASED ON MONITOR SELECT DESIGN

SCHEMATIC

PROTO TYPE

CIR. BOARD

12) EXTERNAL MONITOR BOARD

DESIGN

SCHEMATIC

PROTO TYPE

CIR BOARD

13) VU METER BOARD - SEPERATE UNIT ON SHELF

ONLY USED BECAUSE IT IS ALREADY BUILT

14) LED METERING - ON BOARD

USE RS-12 CIRCUIT REG LED'S OR BAR GRAPHS ????

SCHEMATICS

PROTO TYPE

CIRCUIT BOARD

15) D.A. AMPLIFIER

DESIGN

SCHEMATIC

PROTO TYPE

CIR BOARD

16) 4 PORT EXPANDER BOARD

DESIGN

SCHEMATIC

PROTO TYPE

CIR BOARD

17) POWER SUPPLY DISTRIBUTION BOARD ??

MAY BE NEEDED WITH MULTIPLE BOARDS ??

YEAH, Number 2 is completed !!!!!!

Coming up next on "Let's Build An Audio Console"-------- We were going to do an Audio Amplifier next, but changed our minds. 

I think we may move onto the audio INPUT cards and a way to feed 4 stereo inputs into ONE Input.

Hope you come along.

 

God Speed, Mother Nature.

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The information presented here in this web site is for personal use only and may not be

 used commercially

We make no claim as to the accuracy of the information with-in. 

CHAPTER 9 - - - CLOCK ENCLOSURE

WELCOME BACK !!!!

    We are now ready to mount our Clocks in some type of enclosure. 

    I opted for a side by side configuration right above my computer monitor. I may mount the VU meters above the clocks, but that is a project for another day.

    Since we are not a wood working blog, and your needs will differ, I decided this chapter would be more pictures than design. I will give some helpful hints as we go along. 

    A lot of my woodwork designs are done during the construction rather than before.

    I know that is not the correct way, but it's my way.

    So here we go.

    I am going to start by mounting the two clocks  on a large board, so I can get an idea of the cabinet size that will be needed.

    If I am clever, I can have a skeleton version mounted, then build the box to put it in.

    The first thing to do is figure a way to mount the DISPLAY boards. I opted to mount them right against the Plexiglass. If I can figure out the proper bracket, I can avoid putting bolts through the Plexi.

    I 'think' I have an idea.

    We also need to come up with a scheme to mount the controller board.

    I am going to try to 'hide' the re-set switches behind a magnetic panel that I can remove to set the clocks, then replace it. When I made the VU meter box for my old mixer, I hid all the adjustments behind a wood panel, that I could unscrew to gain access. It worked perfectly.

    Then we mount the Clock boards.

    We want to keep in mind that we may need to get at all of this for any needed repairs or  (or modifications)

    The first thing we did was get a large piece of plywood to use as a temporary base. (We will make a nice one later)

    One the longest side of your board, measure in about an inch and cut a groove along that side. Make the groove wide enough so the RED Plexiglass can slide in.    

Here I have cut a groove in the temporary plywood base to slide in the plexiglass

    Now you should make a set of brackets to hold the display modules.

    I took some aluminum stock, cut it to 10". 

The BLACK mark is where I will bend the aluminum

    I then used my metal brake to bend them into a 90 degree "L" One side of the "L" is ___", the other side is ____". We will be mounting our displays on the short part of the bracket,

BEFORE THE BEND

AFTER THE BENDING PROCESS

    You can also use a hammer and a vice, but they will not come out right.

    You can see the brackets on the right are NOT square, while the ones on the left line up perfectly.  

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    You can get a metal brake at Harbor Freight. This is the one that I use.

METAL BRAKE 

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    You might also be able to find some ready made brackets that will suit your needs.

    The idea is to get the display right up against the red plexiglass.

    Now that we have our brackets made, let's mount up the two display boards.

    Take your time and get them LEVEL !!!

    Here is a shot of the brackets in use.

    We can now proceed to mount the little controller board. It goes underneath the display board. (In the center) Make sure the switches do NOT go beyond the front of the plexi.

When I started to look at mounting the controller, I realized that I did NOT leave any room on one side for the brackets. So I had to re-make them.

Original controller   

 Take your plexiglass over to a bandsaw or scroll saw, and cut out the area for the switch bank.

   
    We will be placing a strip over the front of the  switches to hide them. 

    Here is my initial idea.

    Yes, one of the plexiglass covers is not in the groove all the way. Remember, this is all 'temporary' to get some idea of the sizes and procedure we will use on the main cabinet.

    Now we can mount the two boards (temporarily)

 

I will have to shorten the Ribbon Cables on the Right Side clock.

    At this point I wired it all up and verified that everything was still functioning as designed.

    I did make one more change in the design. Since these clocks are going above the computer monitor, I decided on a separate power supply. I still have the original 5 Volt supply from my last mixer project, so I mounted that in the clock box. You can see it in the picture above. It is right above the clock boards.

    I will use my console power supply to power the timer in the mixer.

    Now that we have some ideas, let's build the box.

    As some of you know, in 1990, my wife and I bought an old Victorian home in the Historic District. After three years of renovations, we moved in and lived there until I retired in 2017. And yes, we made a BOATLOAD.

    When we were renovating, I saved a lot of original Florida Heart Pine. I decided to use this 125 year old wood for this clock cabinet.

    Here are the boards glued up and drying.

    When the glue is dry, I will cut to size and sand, sand, sand, and sand some more. This project calls for some real woodworking. I plan to finish the cabinet in a clear lacquer. The redness of the Pine will shine through.

    If you want more info on Heart Pine and how to buy it, there is a lumber mill just north of us that specializes in the recovery and milling of old logs. They were featured in an episode of Norm Abrams 'New Yankee Workshop.' Most of the wood for Norm's Heart Pine projects came from here.

GOODWIN HEART PINE

    It is by far my favorite wood. 

    Now that the glue has dried, we scrape off the excess with a scraper. Then I will cut it "almost to size" and start sanding.

    One I have sanded to my satisfaction, I will trim all the boards to size. 

    And there you go, a nice cabinet to finish off our clock project....

    Let's build up the easy one. A regular up counter.

 Now we can move on to our next chapter BUILDING THE CONSOLE TIMER

God Speed, Mother Nature.

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The information presented here in this web site is for personal use only and may not be

 used commercially

We make no claim as to the accuracy of the information with-in.